basic info on your v8 lube system


Staff member
now think it thru,
HERES SOME USEFUL INFO, that might help in this thread and the sub links

the first thing Id be doing here, if your not getting a strong oil flow at each rocker while your turn the engine manually and use the oil priming tool, is carefully visual checking of BOTH the valve train rocker geometry and that the push rods are completely hollow and free of debris, by cleaning each with solvent and high pressure air, then mocking the drive train up and verifying that BOTH the rocker and push rod oil feed holes line up at some point in the 720 degrees of rotation, and that the bottom end of the push rods stay aligned with the center of the lifters, seat, this might sound like its a assumed fact, but its easily possible for the push rods to bind on the push rod guide plates or guide slots in the cylinder heads, this potential BINDING will move the push rod , out of its seat on the lifter or rocker preventing proper oil feed out of the lifter or rockers proper alignment, if the oil feed holes are not properly lined up oil won't flow freely.
the oil mist bath, being constantly thrown from the rotating crank assembly unto the lower bore walls,and rockers over the valve train,valve springs, rockers,rods and underside of the pistons does A GREAT DEAL of the initial heat absorption and heat transfer,
and prevents the pistons and rings from being damaged,
only as the hot oil falls, and drains back into the lower sump is much of the heat transferred to the coolant in the block.
oil flow and coolant flow are both required to absorb and remove heat build-up from the engine,especially from the rotating assembly , bearings,and valve train components







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Chevrolet Performance 14091563
Left (Driver Side) Dipstick Plug
Chevrolet Performance 9421743

Right (Passenger Side) Dipstick Plug


On oil pans I prefer studs, and an oil pan back plate


you might want to Use with P/N 12553058 RH and P/N 12553059 LH oil pan reinforcement plates to distribute the bolt stress on the oil pan rail for 1985 and earlier oil pans P/N 14088501 (LH) and P/N 14088502 (RH).1986 and newer

thats a very common question but the answers no!





VS AROUND IT INTO THE BLOCKS OIL PASSAGES, oil enters the area over the oil filter in the block and is forced into the outer holes in the oil filter perimeter down through the case and filter element and up through the central hollow screw retention stud into the blocks oil passages, if the resistance too flow is too great the oil filter bye-pass valve routes oil around the filter directly from oil pump to the blocks oil passages.




yes the oil flows around the mounting stud,from oil pump to main cap to reach the engine oil passages, thru the oil filter



failure to use the correct oil pump,mounting stud, bolt or nut or carefully check clearances when mounting an oil pump can cause problems






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Chevy Oiling 4k.jpg

Chevy Oiling 3k.png

Cadillac Oiling 1.jpg




pressure is a measure of RESISTANCE to oil flow, if the pumps providing flow and yes that needs to be verified,
( because if the oil pump pick-up is less than a 1/4" off the oil pan floor flow is potentially restricted)
if your getting oil flow from the oil pump and no back pressure Id suggest checking the flow control valves, bearing clearances and oil passage plugs at the ends of the lifter gallery passages, any major open to flow oil passage results in very low oil pressure readings





Big Block Chevrolet Gen V and Gen VI Oiling SystemSolving the mystery of the Gen V and Gen VI Priority Main Oiling system
Priority Main Oiling System
The Generation V and VI big block Chevrolet blocks feature a priority main oiling system where the main oil supply passage is located adjacent to the camshaft tunnel. Drilled passages which intersect this large oil tunnel carry oil directly to the main bearings. If you are facing the front of the block with the engine in the upright position, this main oil supply tunnel is located in the 2 o’clock position just below the right hand lifter oil supply line.

Oil Cooler Plumbing
Located along the oil pan rail just ahead of the oil filter pad are two drilled and tapped (3/8” NPT) oil passages for routing oil to an external oil cooler. The hole located closest to the oil filter pad (#2) is for the outgoing supply line to the oil cooler. The front passage (#1), which is farthest from the filter pad, is the return line from the oil cooler.

Careful examination reveals that these two passages intersect the same return line that feeds oil back to the main oil tunnel. This requires that a special fitting be used in the #2 supply line to prevent oil from short circuiting the oil cooler.

Part number SD1540 provides the necessary diverter basket to prevent the supply oil from entering the return line before going to the oil cooler. This fitting has a dash 10AN thread to allow the use of aftermarket components to plumb your external oil cooler. The front passage #1 will require a 3/8” NPT by dash 10AN adapter (#FCM2185), which is available from Scoggin-Dickey.

Understanding By-pass Valve Locations
Factory assembled 454, 502 engines and short blocks have two by-pass valves installed in the block. These factory installed by-pass valves (#25013759) will open at an 11 psi pressure differential. One by-pass valve is installed in the center hole on the oil filter pad (#4). This hole is the oil return passage from the oil filter. The second by-pass valve is installed in the adjacent hole (#3). The egg shaped hole (#5) is the high pressure oil supply passage from the oil pump.

For all racing application that will NOT use an oil cooler but will maintain the stock oil filter location, you must remove the center by-pass valve in location #4. Removing this valve eliminates three redundant right runs in the oil system. However, if you leave this by-pass in place the oil system will still function as it was intended, but a loss of oil pressure can result from the four right angle turns required for oil to return to the main oil tunnel.

If you intend to use a remote oil filter, a high pressure by-pass valve part number 25161284 must be installed in position #3. This valve will open at a 30 psi pressure differential. A plug will be installed in position #4 to prevent oil flow thru this passage. Oil should be returned to the block in the 3/8” hole located just able the oil filter pad. An oil filter block off plate kit (#SD3891) can be purchased from Scoggin-Dickey for Gen V and VI blocks to plumb your external oil filter.

If you intend to maintain the stock filter location and will use the factory provided oil cooler passages to install your oil cooler, then you must install two high pressure by-pass valves (#25161284). One will be installed in location #3 and the second in location #4.

















use this oil pump(link below) in most stock SBC builds, as it produces a 10% increase in oil volume and standard pressure which is just fine , but obviously check your bearing clearances and oil pump to oil pan floor clearances and braze the CORRECT MATCHING pick-up to the pump, and I,d also suggest if you have the room, for clearance that you look into one of the less expensive 7 quart baffled oil pans as they provide a good deal more potential protection and durability to your bearings longevity. be very sure you verify the oil pump pick-up to oil pan floor clearance, and braze the pick-up to the pump body.
yes theres less expensive oil pumps that will work, but thats a good value, in a well made pump.

first choice SBC
or BBC

second choice SBC
keep in mind the sbc oil pump has 7 tooth gears and the big block pumps have 12 teeth making the oil flow smoother and less pulsed, plus having larger gears they tend to supply more oil at lower rpms
look closely and youll see the big block oil pump has a 5 bolt lower cover and the oil pump pick-up with its 3/4" feed seats into the main pump casting while the small block oil pump has a 4 bolt cover and the sbc oil pump pick-up with its 5/8" feed seats into the pumps cover plate

Id also point out that its virtually impossible , in a well designed engine to run the engine "long enough to pump all the oil upstairs."[/img]

as with a properly designed baffled oil pan, with a carefully fitted and clearanced windage screen and crank scraper, the oil pump simply reaches a flow rate pumping oil out of about 100 or so potential lubricant flow leakage points

OIL PRESSURE read on the oil pressure gauge is a MEASURE of RESISTANCE to oil flow, you can REDUCE the pressure the gauge reads by either increasing the engine clearances or REDUCING the oil viscosity (thickness) so it flows thru the clearances faster with less resistance.(OR INSTALLING A SLIGHTLY WEAKER OIL PUMP BYE_PASS SPRING,that limits the pump pressure before it allows some oil to re-circulate back through the bye-pass valve ,from the high pressure back to the low pressure side of the pump impellers, but only the max pressure you reach is limited by the bye-pass spring,in your oil pressure bye pass circuit and its that spring resistance determines the point where the bye-pass circuit, opens and limits max oil pressure, but the bye-pass circuit has zero to do with anything else, if its functioning correctly,
there are many oil leakage points(100) in a standard Chevy engine.
16 lifter to push rod points
16 push rod to rocker arm points
32 lifter bores 16 x 2 ends
10 main bearing edges
9 cam bearing edges
16 rod bearing edges
2 distributor shaft leaks
1 distributor shaft to shim above the cam gear(some engines that have an oil pressure feed distributor shaft bearing.)
once oil exits the bearings or valve train it flows mostly by gravity back to the oil pan sump, but a properly designed windage screen and crank scraper correctly clearanced allows the spinning crank/rotating assembly to act like a directional pump that drags the vast majority of the oil flow back to the sump, by design.
your 55 psi at idle serves no purpose as 15psi-25psi is all thats expected in a new engine with tight clearances using a good 10W30 oil, if your using a higher viscosity than 10w30 its reducing oil flow rates and reducing heat transfer rates, Id suggest using a good 10W30 oil. and use of a 7-8 quart, baffled oil pan and windage tray



10553High pressure performance upgrade for M-55 & M-55A.
Standard volume oil pump.
The 10553 housing and cover are CNC machined and phosphate coated.
Manufactured with pink spring installed for higher pressure (M-55A).
To change pump to lower pressure (M-55) install the supplied yellow spring.
Includes intermediate shaft with steel guide.
The 10553 uses a 5/8” press in screen.


High volume performance oil pump.
10% increase in volume over stock oil pump.
The 10552 is manufactured with the drive and idler shafts extended to allow for additional support in the cover eliminating dynamic shaft deflection at increased RPM levels.
The cover is doweled to the pump housing to assure alignment of the shaft bores.
Screw in plug retains relief valve spring instead of pin.
Relief hole in cover uses screw in plug instead of pressed cup plug.
All bolts are self locking socket heads, with the wrench supplied.
The housing and cover are CNC machined and phosphate coated.
Includes intermediate shaft with steel guide. Uses both 3/4” bolt on or press in screen.
The lower pressure spring is included to reduce pressure if desired.
Patent No. 5,810,571.

10778C (Anti-Cavitation)
High volume performance upgrade for the 10770.
Increase in volume of 25% over stock oil pump.
The same as the 10778 except with the addition of grooves machined in the housing and cover. The grooves reduce cavitation effects in high RPM applications.
Using this oil pump will reduce pressure at idle.
Includes intermediate shaft with steel guide.
Uses 3/4” press in screen.
Racing applications only.
Patent No. 5,810,571


from chevy high performance mag




keep in mind that as oil temps increase the oil viscosity tends to decrease, thus cold oil, at lets say 70F might cause the oil pressure gauge to read 50 psi at idle but the pressure reading slowly goes down to 25 psi once the oils reached lets say 210F, this is normal and expected

you might want to read thru these links and sub links,
as theres a great deal of related useful info contained





(1)pressure is the measure of resistance to oil flow
If you decrease the viscosity to a lighter oil, you tend to increase flow at a loss of pressure. High flow helps to carry away more bearing heat at a faster rate, but it must be balanced with the pressure levels, High pressure helps to keep metal parts like the crank and rod bearings out of direct contact with each other as they are separated by a film of supporting oil (scuffing).â€

(2) the high volume pump can push about 25% more oil , high flow rates result in more heat transferred from bearings, and rockers and valves ETC. to the oil flowing thru the clearances
(3) the oil pump bye-pass circuit limits the max pressure in either size pump to about 65lbs-75 lbs MAXIMUM before it BYE-PASSES enough additional oil volume to limit the pressure
(4) the engine can accept and use only the max flow volume that the engine passages, and clearances can flow at the max pressure the pump provides , at any point less than max pressure the passages can flow only what the pressure and volume provided by the pump supplies
(5)if the bearing clearances can flow more than the pump provides in volume and pressure at any rpm level the film of cooling oil that provides a cushion between the bearing surfaces are at risk of not being supported and separated by that cushion of flowing oil
(6) now since the sweep volume is greater with the high volume pump it will reach that bye-pass circuits max pressure at about 25% lower rpms and supply a POTENTIALLY higher volume of oil to the supply passages/bearings
(7)SO... all a high volute pump does is provide the maximum oil flow the engine can use up to the max pressure allowed by the bye-pass circuit at a 25% lower rpm level if the system can reach max pressure, but it also supplies 25% more oil at every rpm level below that point to provide additional cooling and protection for the engine. and if the engine can flow more than the stock pump can provide the high volume pump helps fill the need faster
(8)oil flow through the bearing clearances INCREASES at a faster rate as the rpms increase
(9) in most engines the oil flow can be provided by the stock pump IF the clearances are close to stock AND THE RPM LEVELS ARE KEPT IN ABOUT THE idle-6000rpm range but if rpm levels exceed ABOUT 6000rpm,or if bearing loads greatly exceed the stock hp levels, or the clearances are greater than stock, the high volume pump is a good idea , simply because it potentially provides that extra volume of oil.
(10) you generally want to run the THINNEST VISCOSITY oil that will maintain about 20-25 psi at operation temps at about 1000rpm, to provide the maximum flow rates, and check the rest of the threads info, synthetics tend to have higher temperature tolerances
there are oil pump testers available commercially or if your mechanically inclined you can fabricate one with reasonable care, after a bit of measuring and purchasing a gauge

any less than about a 1/4" tends to restrict oil flow into the pick-up on many oil pump pick-up pan combo designs and more than about 3/8" to about 1/2 MAX tends to allow air to be sucked under some hard braking or acceleration with some pan and pick up designs so a 3/8"-1/2" pick-up to pan floor clearance is what I tend to try for, Ive seen numerious cases where a high volume pump was installed without checking the clearances (and of course the pick-up moved closer to the oil pan floor simply because the oil pump itself is longer and the pick ups deeper in the pan if its reused from the old pump)and the engine SEEMED to run out of oil pressure almost instantly on acceleration, (Im sure this is what leads to the myth of pumping the pan dry, but simply swapping pick-ups and verifying the pan floor to pick-up clearances cured the lack of oil flow into the pump and restriction that was the true cause of the low oil pressure condition.

remember the high volume pumps have a deeper body to fit the longer impeller gears. this places the oil pump pickup closer to the oil pan floor if no other changes are made when swapping to a high volume pump from the standard pump and can restrict oil flow into the pump

if you choose to install a high volume oil pump you should SERIOUSLY consider the fact that the pump is only a small part of the whole oil system,(which includes a high volume BAFFLED oil pan (7qts or more is ideal) and a windage screen, which is necessary to quickly return that extra oil to the sump, and doing the distributor mod is a big help, as it prevents any potential for cam/gear wear (something already almost non-existent with synthetic oil and the proper distributor gear material.)

the bye-pass spring only limits the pressure at which the bye-pass OPENS thus it only effects the upper pressure limit and has NOTHING to do with oil pressures or flow BELOW that level

BTW heres an old post that will answer several questions

I just got asked

" I just installed a new oil pump and have no oil pressure over about 1500rpm. but IM pulling about 24 psi at IDLE?? whats wrong GRUMPY"
mark iv blocks

mark v blocks

(keep in mind that ALL '91 and later Gen.V and Gen.VI big blocks come with 4-bolt main caps. The two-bolt big blocks are no longer in production
MANY BUT NOT ALL aftermarket head designs have been modified to work on both the early MARK IV 1965-90 and later MARK V & VI blocks 1991-later.)
BTW, , on BIG BLOCKS the oil pumps and oil filter adapters are different due to the block oil filter recess and rear seals being different

GEN V and VI




the oil pick-up needs to be mounted between 3/8-1/2" from the oil pan floor.MOUNT THE PUMPS INTAKE TOO CLOSE TOO THE PAN FLOOR AND YOU LL GET THE RESULTS YOUR SEEING! THE reason is that at low rpms the pumps pick-up can feed enough oil but speed up the pump, the flow requirement goes up and since the pick-up can,t supply the pumps needs, it sucks air and oil pressure falls rapidly to near ZERO ..until the rpms drop back to the point where the pick-up CAN supply the pumps needs


small block oil pumps generally but not in all cases have 5/8" pickup tube dia. while BIG blocks generally but not in all cases have 3/4" pickup tube diam.
keep in mind that in many cases the big block pump can be bolted onto and used on the small block engine (a comon mod) and that you need to carefully check clearances on the oil pump,oil pump drive shaft to distributor length and pan to pickup clearances in all oil pump installations

braze the pick-up tube to the pump body so the pick up is 3/8" MINIMUM, 1/2" maximum from the oil pan floor and use a large lump of MODELING CLAY (every mechanic should have some its great for checking clearances)on the pickup then install the pan temp. with no gasket and remove to measure the thickness of the clay
your local arts/craft store sells it in 1 lb blocks I usually use brite blue or black but suit your self, a digital caliper or even a ruler will get you the thickness measurement your looking for)


once its correctly positioned ,remove the bye pass spring and gears from the oil pump,and have the pick-up brazed or welded to the pump body, then after it SLOWLY AIR cools (DON,T DROP IT IN WATER LET IT AIR COOL)replace the bypass spring and gears, lube the pump,with assembly lube on the gears, check the clearances, check clearances again! and install! just be damn sure its brazed or welded in the correct location as that 3/8"-1/2" is critical to good oil volume feeding the pick-up


worth reading«

silver soldering is basically lower temp brazing , the soldering metal flows over the surface and into micro cracks in the surface of the other metal forming a almost un-removeable bond to the other metals surface it allows you to stick iron to steel or brass to steel, it works more or less like normal solder does on copper but at higher temps and has a much stronger grip in addition too working on iron and steel

I vastly prefer the 5 BOLT BBC style pumps with the 12 tooth gears and their larger 3/4" pick-up VS the small 4 bolt pumps with their 5/8" pick-ups and 7 tooth gears. the oil flow is both higher pressure at low rpms and smoother in pulse pressure spread,no! you don,t need it on a non-race combo, or even on some race combos but its nice to have and I willingly will loose a few hp pumping oil for better engine lubrication

most common question I get? "will a high volume oil pump help or hurt my engine?" followed by some guy saying
"If you're using a stock capacity pan, the high volume oil pump could actually suck out all the oil from the pan before it is drained back in, thus creating bad, bad problems"
absolutely proven false bye SMOKE YUNICK with HIGH SPEED PHOTOGRAPHY and CLEAR WINDOWS IN ROCKER COVERS AND OIL PANbut what can and does happen is the oil pump pickup can and does get mounted or moved too high or low in the oil pan,restricting access to the oil supply, sometimes the pickup comes loose or under hard acceleration or braking the oil in a non-baffled pan can rush away from the pickup under (G) forces, this is not pumping the pan dry, a baffled pan with a windage screen with the same oil supply volume would work perfectly
ok lets look at a few things, pressure is the result of a resistance to flow , no matter how much oil is put out by the oil pump there is almost no pressure unless there is a resistance to that oil flow and the main resistance is from oil trying to flow through the bearing surface clearances and once the pumps output pressure exceeds the engines ability to accept the oilflow at the max pressure the oil return system/bypass spring allows the oil circles back through the pump ,now the amount of oil flow necessary to reach the furthest parts in the engine from the oil pump does not go up in direct relation to rpm, but it instead increases with rpm at a steadily increasing rate that increases faster than the engine rpm due to centrifugal force draining the oil from the rods as they swing faster and faster since energy increases with the square of the velocity the rate of oil use goes up quite a bit faster due to the greatly increased (G-FORCES) pulling oil from the rod bearings over 5000rpm going to 8000rpm than the rate of oil flow increases from 2000 rpm to 5000rpm (the same 3000rpm spread) and remember the often stated (10 lbs per 1000rpm)needs to be measured at the furthest rod and main bearing from the pump not at the pump itself, next lets look at the oil flow itself, you have about 5-6 quarts in an average small block now the valve covers never get and hold more than about 1/3 to 2/3 of a quart each even at 8000 rpm (high speed photography by SMOKEY YUNICK doing stock car engine research with clear plastic valve covers prove that from what Ive read) theres about 1 quart in the lifter gallery at max and theres about 1 quart in the filter and in the oil passages in the block, that leaves at least 2 quarts in the pan at all times and for those that want to tell me about oil wrapped around the crankshaft at high rpms try squirting oil on a spinning surface doing even 2000rpm (yes that's right its thrown off as fast as it hits by centrifugal force, yes its possible for the crankshaft WITHOUT A WINDAGE SCREEN to keep acting like a propeller and pulling oil around with it in the crank case but that's what the wrap around style milodon type windage screen is designed to stop)the only way to run out of oil is to start with less than 4 quarts or to plug the oil return passages in the lifter gallery with sludge or gasket material! now add a good windage tray and a crank scrapper and almost all the oil is returned to the sump as it enters the area of the spinning crankshaft! forming a more or less endless supply to the oil pump, BTW almost all pro teams now use DRY SUMP SYSTEMS WITH POSITIVE DISPLACEMENT GERATOR PUMPS that are 3,4,or 5 stage pumps each section of which has more volume than a standard volume oil pump because its been found total oil control is necessary at high rpms to keep bearings cool and lubed.
keep in mind both engine oil temps and trans fluid temps seldom reach operational temps,
and stabilize , for semi consistent data,in under 12-15 minutes of drive time.

ok look at it this way,what your trying to do here is keep an pressurized oil film on the surface of all the bearings to lube and cool them and have enough oil spraying from the rod and main bearing clearances to lube the cam and cylinder walls/rings. now a standard pump does a good job up to 5000rpm and 400 hp but above 6000rpm and 400hp the bearings are under more stress and need more oil flow to cool and because the pressure on the bearings is greater you need higher pressures to maintain that oil film.lets look at the flow versus pressure curve. keep this in mind, good oil flow volume across the bearing surfaces to cool and lubricate them and to provide a boundary layer between the metal surfaces is more important than the pressure reached at all rpms. since oil is a liquid its non-compressible and flow will increase with rpm up to the point where the bypass circuit starts to re-route the excess flow at the point were the pressure exceeds the bypass spring pressure. but the volume will be equal to the pumps sweep volume times the rpm of the pump, since the high volume pump has a sweep volume 1.3-1.5 times the standard pump volume it will push 1.3-1.5 times the volume of oil up to the bypass circuit cut in point,that means that since the engine bearings leakage rate increases faster as the rpms increase because the clearances don,t change but the bleed off rate does that the amount of oil and the pressure that it is under will increase faster and reach the bypass circuit pressure faster with the high volume pump. the advantage here is that the metal parts MUST be floated on that oil film to keep the metal parts from touching/wearing and the more leakage points the oil flows by the less the volume of oil thats available for each leakage point beyond it and as the oil heats up it becomes easier to push through the as the rpms and cylinder pressures increase in your goal to add power the loads trying to squeeze that oil out of those clearances also increase. ALL mods that increase power either increase rpms,cylinder pressures or reduce friction or mechanical losses. there are many oil leakage points(100) in a standard Chevy engine.
16 lifter to push rod points
16 push rod to rocker arm points
32 lifter bores 16 x 2 ends
10 main bearing edges
9 cam bearing edges
16 rod bearing edges
2 distributor shaft leaks
1 distributor shaft to shim above the cam gear(some engines that have an oil pressure feed distributor shaft bearing.)
so the more oil volume the better.Chevy did an excellent job in the design but as the stresses increase the cooling volume of the extra oil available from the larger pump helps to prevent lubrication delivery failure, do you need a better pump below 5000rpm or 400hp (hell no! at that level the stock pump works fine) above that level the extra oil will definitely help possible deficient oil flow and bearing cooling and a simple increase in pressure does not provide a big increase in volume that may be necessary to keep that oil film in the correct places at the correct volume at all times.the stock system was designed for a 265cid engine in a passenger car turning a max of about 6000 rpm but only having the stress of under 300hp transmitted to the bearings, Im sure the original designers never thought that the sbc or bbc would someday be asked to on occasion hold up to 450-800hp and 6000-8000 rpm. nor did they foresee valve springs that placed sometimes as much as 500lbs and up loads on the lifters and the use of over 9 to 1 compression ratios in the original design so the oil volumes and pressures necessary to cool those valve springs and bearings at those stress levels were never taken into account for that either , the stock pump works but was never designed for the loads and rpms that a modern engine hotrodded to over 450hp sees

the standard volume pump gears are about 1.2" long the high volume pump gears are about 1.5 inches long (depends on manufacturer)
heres the descriptions right from Chevy

SBC Oil Pump, High Pressure Z28/LT1. Production high-pressure oil pump with 1.20" gears.Will produce 60-70 psi oil pressure. Does not include screen. The pickup tube dia. is 5/8" for this pump.

SBC Oil Pump, High-Volume. This high-volume pump has1.50" long gears.It has approximately 25% more capacity than a production pump at standard pressure. Does not include screen.

and yes I comonly build small blocks useing bbc oil pumps like the ls7 pump, it has 1.3" gears but they are bigger in dia. and have 12 not 7 teethlike the small block pumps (many standard sbc pickups use 5/8" dia. pickups) (the ls7 pump is best used on 8qt-9qt road racing oilpans as the larger 3/4" pickup flows lots of oil for extreme high rpm engines with a multi baffled pan using windage screens, scrappers and cut outs for extreme (G) loads where a dry sump can,t be used or cost makes you stick to a wet sump pan. these LS7 pumps don't fit most sbc oil pans so your stuck using the high volume sbc oil pump if your not using a true racing 8-9 qt style oil pan in some cases

since I just got an E-MAIL about what mods are necessary or at least a good idea when running a high volume oil pump, and concern over possible extra gear wear caused by the slightly and I do mean slightly increased pressure on the gears, guys Im getting the idea here that most of you are not aware that your normally suppose to cut a .060 wide x .005-9 deep groove in the lower band on the distributor housing so that extra oil sprays constantly on the contact point between the cam and distributor gears and that a ARP style drive shaft with a steel collar to hold the drive shaft alignment on true center is mandatory for long high rpm use. look at this picture:


The groove is cut under the bottom (O)ring in the band just above the gear (look at the picture above, (BTW the pic shows a smaller groove than ideal)) and in line with the gears so that oil sprays on the gear contact points at all times, this is a mod most old time racers know about and use, but Im getting the idea the new guys have not picked up on it! (those two bands form the side of an oil passage in the block and the distributor shaft seals that passage, cutting the groove sends a spray of high pressure oil onto the contact point at all times, if you don't cut the groove your relieing on returning zero pressure oil flowing down the rear lifter gallery drain holes to lube the gears
BTW the other way to do this is to groove the block in the distributors lower band area as this keeps the location of the oil jet constant as the distributor is turned, for a full contact spray on the gears so I generally do BOTH
heres more OIL info



theres three potential GATES or valves in the oil flow path thru the blocks oil passages, the pump provides oil flow, and a bye-pass valve internal to the pump limiting max oil pressure to the spring resistance selected (usually 60-75 psi)



many oil filters have an ANTI-DRAIN BACK VALVE



many oil filter adapters have a oil filter bye-pass valve, that opens if the resistance to oil flow exceeds 10 psi



Don’t forget the “forgotten†plug. If you don’t remove it before the block is cleaned, debris can hide in the main oil passages. And if you forget to reinstall it before the rear main cap is bolted on, oil will not be directed through the oil filter!





first gen small block oiling




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one or at the most two of outer plugs for the oil passages plugs above the cam, drill a .030-.038 hole in one or both , naturally the one on the left is preferred as the rotation favors that side for spraying oil everywhere under the timing cover

BTW DRILL the removed oil passage plugs, while they are clamped between a couple boards with a drill press If you can, you don,t want metallic shavings in the engine

don,t get too wrapped up in worrying about which oil is superior, keep in mind oils main function is to provide a lubricating film and transfer absorbed heat,away from the moving parts, almost ANY of the name brand oils do that well and ALMOST ANY oil will last at least 5000 miles without significant loss of its abilities to do that if the filters used keep the particles in it minimized AND the temp stays in the 190F-250F range. but like I stated earlier, oil needs to get up to 215F at least for a short time to burn off moisture, and above about 240F it slowly brakes down, its the regular replacement with clean oil , to remove the crud from the engine and good filters that's the key!
EVEN if you had the best oil in the world, that could easily last 30K-35K miles the CRUD & acids trapped in the oil from combustion,would cause wear and reduce its lubrication abilities over time, if the filters don,t remove the majority of that crud the oils life expectancy is limited regardless of the oil quality itself , and regular replacement is the key

a few pictures above may help

a high volume pump has slightly longer gears, usually about 10%-20% longer, that build the volume of oil pushed thru the engines oil passages,and engines clearances 10%-20% faster at any given rpm, PRESSURE is a measure of resistance to oil flow thru those clearances, theres a bye-pass circuit in the pump designed to open and limit the pressure at a set pressure level, that's usually 60-65 psi in a high volume pump and at 65-70 psi in a high pressure pump, theres no real disadvantage unless the pumps bye-pass circuit is not functioning correctly and starts to restrict the flow and the pressure builds to higher levels than intended resulting in resistance to the pump which adds drag and eats hp.
theres no lubrication increase past about 55-60 psi of oil flow thru the bearing clearances so the idea is to match the oils viscosity to the engine clearances at the engines operational temperature and to use an oil cooler and the engines oil bye-pass circuit to maintain the pressure and temperature within known, and predicted limits.
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Ive always found the best results from keeping the low rpm pressure in the 30psi at idle and no lower than, in the 15psi-20psi at hot idle range and no more than 65psi at high rpms,is really useful, the voluum required depends on the way the engines clearances and oil systems designed or modified ,voluum/viscosity/clearances in the approximately stock range works fine in most .
I like high volume pumps but I certainly don't use them IF the engines nearly stock as the standard Z28 SBC pump works fine
"the standard volume pump gears are about 1.2" long the high volume pump gears are about 1.5 inches long (depends on manufacturer)
here's the description's right from chevy


obviously the small groove is intended to flow extra oil volume to the rear vertical thrust bearing surfaces

If your not getting oil to the rockers but have 65 psi as the engine idles,
Id suspect either the cam bearings (especially the rear cam bearing or the oil passage plugs under the timing chain are incorrectly installed







in a properly set up block a pressurized oil film supports the cam and main bearings
oil flows around the outer bearing in the groove in the back of the bearing and the matching groove in the cam journal cut in the block


SBC Oil Pump, High Pressure Z28/LT1. Production high-pressure oil pump with 1.20" gears.Will produce 60-70 psi oil pressure. Does not include screen. The pickup tube dia. is 5/8" for this pump.

the true high voluum pumps like this below are not necessary UNTILL youve done extensive mods that require the expra oil flow voluum

SBC Oil Pump, High-Volume. This high-volume pump has1.50" long gears.It has approximately 25% more capacity than a production pump at standard pressure. Does not include screen."


Now the question always comes up, why do I need a high volume oil pump and 6-8 quart oil pan, the main reason you'll use a high volume pump to begin with is to provide more volume of oil,at any given rpm,oil that cools the rings, rockers, bearings,that are being stressed to levels the original engineers ever expected. etc, plus at high rpm levels there 2-2.5 quarts of oil in the valve covers, lifter gallery and trapped rotating with the crank assembly if you don,t have a windage screen and baffled oil pan, now hit the brakes or accelerate hard, oil stacks into one end of the oil pan and theres darn little oil left above the oil pump pickup with a non baffled 4-5 qt oil pan,but the mods are really , required only if you have increased the oil flow rates,by increasing the bearing clearances,and re directing oil and as a result you also need to control the flow better and have more oil in the sump, ordinarily the engines needs are supplied, and the adequate volume can easily be supplied by the standard oil pump if you have not increased the clearances and done a few other mods to increase the oil flow rates to parts in the engine to increase the flow rates to cool and lubricate the components.
so the obvious question is why do you bother doing the mods in the first place, if the standard pump will work, the answer is the standard pump works fine up to the limits it was designed for, and thats a engine of about 327-350 cubic inches and spinning under about 6500rpm that produces under about 370hp,
once you start to exceed that theres a few modifications that can, if done correctly increase the cooling and engine durability, but those mods require a greater volume of oil flowing over parts to cool and lubricate them than the stock pump cam provide, if you read the linked info you'll see that there are modifications to a, stock sbc to convert it into a race engine that are neither needed or useful on a street engine, but due to the far higher stress levels in a race engine those mods become more important to durability.
its the quality of the oil.
its additives and formulation that will provide most of the lubrication,protection to the moving surfaces and its the viscosity that provides the resistance to flow through the bearing clearances, its that resistance to flow that's being read as BACK pressure or oil pressure on your gauge, thinner oils like 10w30 tend to pump faster and cool better with the higher flow rates , and because most wear in any engine occurs during start-up before pressurized oil flow can force a protective film between moving surfaces the automotive manufacturers have, along with the conversion to roller lifter based valve trains, slowly graduated to the thinner and lower viscosity oils,because they realize the benefits.
As long as you have at least 15-20 psi oil pressure at idle once the cars up to full operational temps (generally 180f oil temps) youll be better off with the thinner synthetic oils that have a higher heat tolerance in many engines

now Im sure you want to know what mods, well that depends on the application
but I generally put a small groove in the block in the distributor shaft mount hole to spray extra oil flow directly onto the cam/distributor mesh point
I generally drill the two forward cam oil passage plugs with a .036 dril bit to spray oil into the back of the cam gear.

I generally use this tool,(below) to insure extra oil too the cam lobes

on solid lifter engines I use these

I also run an OIL COOLER,


and a decent oil pan


several places sell sump extension kits so you can add capacity to the oil system


Ive also smoothed/enlarged the blocks drain passages, installed magnets to pick up metalic dust

I run a mix of 9 QTS of mobile 1 10w30 and 1 QT of MARVEL MYSTERY OIL in my 10 qt oil system in my main toy(the 1985 corvette) and a similar ratio in my other two vettes, but the longer I build and race cars the more Ive come to beleive that almost any decent name brand synthetic with some MMO added to get the extra solvents and detergents that the MMO has added will work just fine just keep the air and oil filters changed out at about 3000-3500 miles and the oil changed at 3500-7000 miles, and making darn sure you use a QUALITY oil filter and have a few MAGNETS in your oil pan.
the larger capacity baffled oil pans with a windage screen, help here as they tend to keep the temp stable and the oil sump full
naturally your success will depend on keeping your oil temp in the correct operational range (190f-215F most of the time,max -250F) once the cars up to temp (preferably in the 215F-230F range at least several times during each drive so it burns of moisture and can lubricate and flow correctly,(non-synthetics should not exceed about 230F and generally work best in the 190F- 215F-225F range) and having the bearing clearances correct.
oil pressure should be between about 20 PSI at idle(once its up to temp.) and 60-65psi at high rpms.
but again the KEY if frequent oil and filter changes, failure, to change the oil and filters is usually the main problem but if the oil doesn,t reach 215F oil forms/traps moisture and tends form acids that are bad for bearings



BTW, keep the oil temp in a narrow range and TUNING the engine if FAR easier


viewtopic.php?f=54&t=4793Small Block Chevy Oil & Lubrication Systems
The Chevy smallblock lubrication system is very reliable and presents no design defects to worry
about. Just keep everything clean. Change the oil and filter on a regular basis, and it will provide good
service for more than one hundred thousand miles. If the recommended main and rod bearing and
rod side clearances are maintained, a stock volume oil pump is all that is required. A high-volume or
high-pressure pump or an oil pump from a bigblock Chevy are not needed in most street applications.
These other pumps take additional horsepower to run and add more strain on the cam/distributor
drive gears and drive shaft. Checking the operating clearances on the stock oil pump and optimizing
them if necessary, will ensure adequate oil pressure. The clearance between the pump gears and the
pump gear cover should be .002" to .0025". If there is more clearance, take a sheet of 400-grit
sandpaper and some oil, then move the main pump body in a figure-8 motion over the wet sandpaper
to remove material until the clearance is correct. If there is less than the minimum clearance, you can
sand the pump gears. Remember to Loctite the pump cover bolts when you put the pump back
Stock small block oil pump Oil pump drive shafts compared

The stock standard volume smallblock oil
pump will give excellent service in most
applications. Make sure that the pickup screen
you use fits the depth of the oil pan and that
the pickup tube is welded or bolted to the
pump body.
The oil pump drive shaft on the left fits any
Gen. I smallblock except the 400. The 400
shaft on the right is necked down in the center
portion to clear the wider main caps found on
the 400.

Oil pump pressure relief spring
You can increase the operating oil
pressure in a standard volume oil
pump by changing the pressure relief
spring to the Z-28 302 spring offered
under (PN-3848911, color-coded
white). With this high-pressure spring,
there is no need for washer shims or
carb jets. Operating pressures will be
65 to 70 pounds.

Two different oil pump intermediate drive shafts have been used in Gen. I blocks. All Gen. I blocks
except the 400 use a drive shaft that is 53⁄4" long overall and is the same shaft diameter its entire
length up to where the plastic or metal coupling sleeve attaches. The 400-style shaft is the same
length, but the diameter is necked down in a portion of the shaft to clear the wider journal 400 main
caps. The oil pump drive shaft for a Chevy bigblock is longer (61⁄2" overall) and is not
interchangeable. Gen. II engines that have a front-mounted OptiSpark distributor use an oil pump
drive shaft stub, which connects the gear on the rear of the cam to the oil pump. If you have a Gen. II
long-block and elect to use a Bowtie four-barrel carburetor aluminum intake and a rear-mounted
distributor, you must change the oil pump stub drive shaft to the conventional intermediate drive shaft
found on Gen. I motors.

Have the oil pump screen and pickup tube welded to the pump body. Remove the pump’s pressure
bypass spring in the pump before you do any welding to prevent heat damage to the spring. There
are some aftermarket pickup screens and tubes that will bolt to the pump and give positive retention
of the pickup instead of welding.

Make sure that you prime the oil pump before you install it. Squirt some oil into the pump or stick the
pickup down into some oil and turn the pump shaft by hand to coat the pump gears. This ensures that
the pump will move oil as soon as the new motor is turned over the first time you start it. It’s also a
good practice to use a priming tool on an assembled motor, before it is started for the first time. Oil
can then be pumped throughout the engine.
Continue to use the priming tool until you see oil come out of all of the rocker arm oiling holes.
Check that there is 1⁄4" to 3⁄8" clearance between the lowest point of the pickup screen and the
bottom of the oil pan.

Generally, the rule of thumb for oil pressure is 10 pounds of pressure for every 1,000 rpm. For
example, you should have 40 pounds of hot oil pressure at 4,000 rpm, 50 pounds at 5,000 rpm and
60 pounds at 6,000 rpm. Chevrolet makes a high-pressure relief spring (PN-3848911). It is color
coded white and will provide a maximum of approximately 70 pounds of oil pressure. This spring is
used in high-performance oil pump (PN-3848907). You can add this spring to a stock standard
volume oil pump for increased line pressure.
(PN-3848907) is a standard volume oil pump with Z-28 pressure relief spring.

(PN-3848911) is a pressure relief spring; Z-28; 70psi.

(PN-3855152) oil pump pickup screen and tube is used with (PN-465220) Z-28 oil pan and standard
volume Z-28 pump.

(PN-10046007) is an oil pump mounting bolt.

(PN-3998287) is an oil pump / distributor drive shaft, use with plastic retainer / connector
(PN-3764554 or 10105879)
If you do use a high-volume or high-pressure oil pump, use a pump drive shaft that has a metal
coupler instead of using the stock plastic coupler. The LS1 Gen. III 350 uses a front-mounted gerotor
oil pump that is driven by a gear on the crank snout. A long pickup tube is routed from the pump to
the pickup screen in the Gen. III cast aluminum pan.
Oil Pans
First make sure that whichever oil pan you intend to use will fit inside your engine compartment
without hitting the front suspension crossmembers. Also determine on which side of the engine the
dipstick will go. It must match the dipstick location in the block and the oil pan. If you mistakenly put an
oil pan with a passenger side dipstick location on to a block with a driver’s side dipstick location, you
can develop an oil leak. Check these things before you build the engine and certainly before you
install the engine into the vehicle.

Over the years, two-piece rear main oil seal pans used two different thicknesses of seals between the
front oil pan surface and the timing chain cover. Here’s how to tell which front pan gasket to use. On
engines from 1955 to ’74, a 1⁄4" thin gasket was used; and from 1975 to ’85, a 3⁄8" thick gasket was
used. Take the oil pan you’re going to use and place a straightedge across the pan rails over the
front gasket half-moon opening. Measure the distance from the seal surface to the bottom of the
straightedge. If the distance is 21⁄4" use the 1⁄4" thin seal. If the distance is 23⁄8", use the 3⁄8" thick
seal. You can use a two-piece seal oil pan with a thick gasket on a block that originally used a thin
gasket and pan, if you must. Just make sure you use the appropriate front pan seal and that the pan
has the dipstick location that matches the block and location that you need.
A Moroso deep sump oil pan
A Moroso deep sump oil pan. Note
the trap door baffle to keep oil
around the oil pump pickup screen
and the curved portion of the pan
rail to accommodate a driver’s side
dipstick and tube.

Also, make sure that you use a pan for a two-piece rear main oil seal with a block that has the
two-piece rear seal. Likewise, a one-piece rear main seal block and crank requires an oil pan suited
for this application. Chevy and some aftermarket suppliers do make adapters to mount a two-piece
seal crank into a one-piece seal block and use the appropriate pan. Make sure you figure this all out
and make your parts selection before you build the motor.
Moroso deep sump oil pan
Make sure that the type of pan
you have chosen will fit in the
engine compartment of your
vehicle. This type of deep sump
pan oil fits most vehicle

(PN-359942) is a 5-quart oil pan with trap door baffles and a bigger sump. It was used on Gen. I
engines in Corvettes with a two-piece rear oil seal block; driver’s side dipstick position. This pan will fit
pre-’86 Corvettes, but may not fit your application due to crossmember clearance problems with the
larger sump.

(PN-360866) is a Corvette 4-quart Gen. I oil pan with a driver’s side dipstick and is used with two-
piece rear main oil seals.

(PN-465220) is a 1969 Z-28 Camaro oil pan with better baffling, for use with two-piece rear seals. This
pan has a 4-quart capacity and a driver’s side dipstick for use with Gen. I blocks.
(PN-465221) is the standard production Gen. I 4-quart oil pan. Chevy windage trays will not fit this
pan. It is used with two-piece rear seals and has a driver’s side dipstick location.

(PN-10055765) is a 1986 and newer Corvette 5-quart Gen. I and II pan for use with one-piece rear
main seals. It has a passenger side dipstick location.

(PN-10066039) is a 4-quart pan for two-piece rear seals and is used on the Gen. I Goodwrench
350/190hp, 350/285hp crate motors. It will clear and fit most front crossmembers

they still sell these and you could modify them or use as designed

this lower designs what Ive used for decades:like:
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BTW, for you big block guys, you want the oil pressure to be at least 15psi at idle and it should jump up quickly as the rpms increase, and as long as theres oil flowing fairly steadily from every rocker arm and pushrods at idle you should be fine, it doesn,t need to be squiting from the rockers,over the fenders, the design of the valve train, the geometry of the lifters too the oil passages in the block, the rockers to pushrod oil passages and rocker geometry all effect the flow rates, but its not necessary to squirt oil over the fenders to effectively lube and cool the valve train. a steady trickles at idles ok, (looser lash or less preload generally increases the flow voluum ,you may also want to verify the pushrods are clear inside and theres no sludge and the holes align for full oil flow, you might also check the clearance or lash (solid lifters)or lifter preload (hydrolics) and the viscosity of the oil used, and verify the pushrods don,t bind even slightly in the pushrod guide plates durring ANY point durring the full travel arc of the rockers as that does effect the volume of oil that reaches the valve train, get the rocker geometry and clearances correct and if the oil pressure is correct and you don,t abuse it too much the engine will last a long time.

the most valuable tool you can acquire is as broad a selection of valid information,
on exactly how and why things work in your car,s engine, drive train
and suspension , as a reference base to work from,
and acquiring a good set of testing and measuring tools to verify and test with
you really should get these books and read them before going any further, it will help a good deal





From the Manufacturer: Cool Collar Lab Test Results:

Test Results Laboratory Test

Castrol GTX 10W30 motor oil was heated to a temperature of 220 degrees F. and pumped simultaneously through two identical oil filters. One oil filter had a Cool Collar attached, the other did not. A fan was used to direct seventy degree F. ambient air over both oil filters at a velocity of fifty miles per hour. The oil exiting the filter having the Cool Collar installed indicated a h eat removal approximately equal totwo degrees per minute. Whereas the oil temperature exiting the filter without the Cool Collar showed no change. (Typically an automotive engine passes all the oil through the filter more than once per minute).

Summary: With a constant heat source applied to the oil, the temperature dropped to 202 degrees F (from 220 degrees F.) with five minutes. This translates to a 12% temperature decrease of the heat added to ambient temperature.

Liquid Cooled Automotive Engine (Road Test)

This test was an actual highway test. The car used was a late model Corvette equipped with digital readout oil temperature and coolant temperature gauges. On a 72 degree F. day, at 65 miles per hour, the oil temperature read a constant 221 degrees F. The water temperature was 195 degrees. The corvette was then pulled off the road and a Cool Collar was installed. Testing was then resumed. Within a distance of five miles the Cool Collar was responsible for lowering and maintaining the oil temperature at 203 degrees F.

Summary: Our tests again indicated a 12% approximate reduction above ambient temperature of oil heat. On similar testes, it was found that after installation of the Cool Collar the oil temperature will typically drop near to the level of the engine coolant temperature.

Air Cooled Engine (Road Test)

The test vehicle used was a 1978, 911SC Porsche, equipped with a Carrera style oil cooler. The car was driven 65 MPH on a 85 degree day for approximately 35 miles. The car was then stopped and a I.R. thermometer was used to check the temperatures at various points along the oil lines, tank and cooler. In addition, the reading on the dash temperature gauge was noted. An average temperature of 220 degrees was logged.

Testing was then resumed, with the Cool Collar installed on the oil filter, over the same coarse and speed. At the end of the 35 miles the temperatures were then checked again using the infra-red thermometer at the same points as before. The indicated temperature readings showed an average reading of 208 degrees, a reduction of 12 degrees.
BE AWARE NOT ALL BBC OIL PUMPS FIT ALL BBC ENGINES, the LATER GEN V, and GEN VI HAVE A DIFFERENT PUMP due to main cap clearance issues (YEAH IM AWARE they can be retro fitted)


Im 68 years old and Ive been building and racing cars and engines since I was in my teens,Ive probably built an average of 3-4 BBC, and or SBC engines a year
(with more than a few mopar, caddy, Buick, Pontiac engines along the way)
mostly for the local muscle car guys and myself over the last 45 plus years and I can assure you both research and experience maters, I look back at what I built during my 20s and remember the frustration I felt not knowing what was required and thinking about all the mistakes I made back then I have constantly tried hard to help the newer guys avoid many of the pit-falls I learned from.

yeah reading links sucks but it takes far less time and wastes FAR less money than blindly and randomly jumping into an engine build ignoring the potential problems and knowing what your doing and why and how its done never hurts
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The most sophisticated windage tray available today! This exclusive Milodon design features hundreds and hundreds of small louvers that quickly scavenge oil from crankshaft rotation, but prevents reversion common to screen-type windage trays. This is a completely finished, gold irradiated part that does not require additional fitting. And it flat works! Extensive dynometers and on-track testing verifies that Milodon "Diamond Stripper" windage trays out-perform all other screen type trays on the market.
These trays will fit both the Small Block Chevy 350 and 400 main cap bolt pattern. They will also fit right and left hand dipstick engines, as when adjusted properly the dipstick will pass underneath the tray.


32640, #32645

Additional "free" horsepower can be found by the installation of a crankshaft scraper. A scraper will remove any excess oil left on the crank & rods that the windage tray does not remove. Scraper requires fitting to individual crank and rod profile, as well as to engine stroke. Wiper should be fitted to within .045" from rods and .035" from crank counterweights. When installed, scraper is sandwiched between pan rail and block.
Small Block Chevy 32640 \


What do the scrapers bolt to? The pan rails, what do they do?

they either bolt to the block,between the oil pan gasket and the pan or you can weld them to the oil pan rail, on the oil pan,most guys braze or J&B EPOXY THEM TO THE OIL PAN RAIL, no they don,t touch the rotating assembly, you place them and carefully trim them, durring the engine assembly process, so that while you spin the rotaing assembly the teeth miss the outer arc of the rotation by about 1/8" and they are placed on the side of the engine that sees the rotation upwards from the sump, the idea is to restrict oil flow from the sump following the spinning assembly around in the lower block, it helps skim away and restrict oil falling from the upper engine, to remain in the sump area of the oil pan, after the crank assembly sweeps it into the sump.
that way almosrt all the oil makes only a 100-250 degree trip around with the spinning crank a single time, before being forced back into the oil pan.

the combo of these two components and an oil pan similar to this


will provide better oil control

Most synthetics tend to have a wider heat tolerance and they can go longer between oil changes as they don,t tend to break down as quickly, but you will generally want to at least change the oil filter out at the 3500-5000 mile point and Id certainly suggest changing oil and filter with synthetics at no longer than the 7000-10,000 mile point no mater what some of the advertizements claim, simply because although the oil may be ok, its got a good bit of crud in suspension, and acids and metallic dust in the filter at that point.
ALL the mineral base motor oils will mix with MOST synthetics with zero problems, and theres no reason, not to mix if you can,t get access to strait synthetic oil, as an example IVE always thrown a qt of MARVEL MYSTERY OIL in with mostly synthetic MOBILE 1 oil in my engines, but Id use KENDAL GT,VALVOLINE,TEXACO, SHELL, ETC, if I can,t get mobile 1 on a trip to top off if I'm running a bit low.
some SEALANTS are not designed for use with synthetic oil, as an example that yellow weather strip adhesive contact cement many guys use slowly dissolves in hot synthetic oil over several months resulting in oil leaks if it was used where it was never designed to be used as an engine gasket cement


Look closely at this picture its quite common for a non-brazed oil pump pick-up to vibrate loose over time until like this one has obviously done, if the oil pump pick-up rotates down until it touches the oil pan floor,it almost always causes oil pressure and flow to be reduced, thats bad because in restricts oil flow into the oil pump and tends to increase bearing wear rates,bu iit can get even worse, it may take months or even years but if it vibrates down to touch the oil pan floor, theres a good chance that it will eventually vibrate loose and fall out of the pump casting, thats why brazing the pick-up to the pump body and using a brace that bolts to the pump increases durability.
the oil pump pick-up should remain parallel with the oil pan floor and at a distance of between 3/8" min to about 1/2" max to maintain maximum flow rates thru the oil pump



Ive generally found the 12 gear tooth BBC oil pumps to work very well, on both the SBC,
if you need significantly more oil flow than the stock z28 style pump provides,
(unlikely on a nearly stock SBC)

and the LS7 BBC works well on the BBC engines.
a great many problems seemingly related to oil pumps,
are really the result of improper clearances on the oil pump pick-up to oil pan floor.
or use of the wrong oil pump drive shaft length or type.

you have several potential major sources for traditional wet sump SBC and BBC oil pumps
obviously youll want to shop carefully to correctly match the pump and pick-up combo ,
to the engines requirements and oil pan clearances


MELLING oil pumps&ar=1&kr=melling chevy oil pumps



related threads with info you might want

oil system mods that help

heres a short list REMEMBER the object or goal in building and maintaining the lubrication system is too maintain a 100% dependable pressurized cooling flow of lubricant to the bearings, rockers,valves etc. obviously use of a high quality synthetic oil that has a higher heat tolerance and that...

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The question comes up rather frequently when I suggest buying or modifying oil pans as to "WHY BOTHER?" well its simply the fact that most stock oil pans were designed simply to be the cheapest to manufacture component that would function on an engine that would rarely be spinning over 3500rpm...

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heres an old post "Any source for the magnets Grumpy? what do you use? " ... SH&cat=167 magnets are ceramic and glass hard, don,t try to drill or grind them, as they can shatter or proper magnets trap...

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an oil accumulator is basically an aux pressurized oil tank , that in most cases holds 1.5-4 quarts of oil in reserve, the engine oil pump pumps it full once the oil pressures in the engines oil passages is high enough, and feeds it back into the passages under pressure if the oil pump sucks air...

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Grumpy: Read your post on the subject of Valve Spring Cooling with Engine Oil. Thanks VERY MUCH for bringing this to my attention. I have built a SBC 383 stroker going into a 1971 Datsun 240Z. Used a shaft rocker setup, but am uncertain that the trunion is being lubricated via Engine Oil...

bearings and oil flow

Bearings and oil flow viewtopic.php?f=53&t=88 ... cation.htm

Shimming An Oil Pump Relief Spring

I was recently asked HOW to shim an oil pump relief spring to gain added oil pressure!:rolleyes: many pumps come with two springs , one standard and one high pressure you should NEVER shim an oil pumps pressure relief spring back in the 1950s-1960s it was common to pull the pressure...
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its fairly comon practice for race engines to install a course meash screen over the oil return holes in the block to limit the travel of fragmented valve train components, should something rather nasty occure and bits and pieces of fragmented valve train find thier way into the lifter gallery, Ive always used 3/16" -or 1/4" grid stainless screens and used epoxy too secure the screens to the block surfaces over the drain back holes, along with high temp magnets, the reason is that a single roller bearing , bit of shattered valve spring,or valve keeper that gets into the lower engine can do an amazing amount of damage and its PREVENTABLE with the magnets and screens installed



moroso sells kits but you can easily do it yourself

viewtopic.php?f=62&t=1518&p=3473#p3473 ... Code=13021

J&B weld works if the blocks been degreased before the epoxys used

IVE used it for many years with zero problems

btw, add a few magnets to the oil pan and drain back area in your engine, the trap and hold metalic dust that comes from wear and increase engine life span by preventing that crap embedding in the bearings

these are even more tollerant of temp swings and retain strength at even higher engine oil temps plus they are smaller and easier to use

custom made by HELICOIL, this shows hes thinking things thru!

The SH material in the D66SH magnets, means that the magnets can be heated to 300° F without any loss of magnetic strength, unlike standard neodymium magnets that begin to lose strength at 175° F. Suitable for many high temperature applications. ... study.html

if your worried about the potential for valve train shrapnel getting into your engine use several of these magnets in the lifter gallery and oil pan and shrapnel screens in the lifter galleries, its amazing the crud they collect and hold and prevent from getting into the oil pump

yes controling heat is a very significant issue but,
maintaining a pressurized hydraulic film of lubricating oil between the moving surfaces is critical, for durability.
honestly the engines lube system is critical to long term durability, and you really can,t reasonably expect an engine to last if you don,t maintain consistent cooling and lubrication.







keep in mind that your oil pressure gauge measures the resistance to flow the oil sees as it flows thru the bearing clearances, larger clearances will require higher flow rates or a higher viscosity oil, higher flow rates can be supplied with a high volume oil pump but that also requires a larger baffled oil pan and windage screen to control the higher oil flow rates
















yes controlling engine and lubrication oil heat is a very significant issue but,
maintaining a pressurized hydraulic film of lubricating oil between the moving surfaces is critical, for durability.your valve springs won,t last 20 minutes without some cooling oil flow to prevent them from over heating and I can,t believe how many people actually believe a crank shaft journal actually rides directly on the bearing surface , without that pressurized film of oil separating the two moving surfaces the bearings are going to be trashed in minutes
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comp cams sells a lifter bore groove tool linked to here


chevy has a .842 factory lifter bore diam.
use of quality oil and roller lifters and a billet can core helps, keeping the spring load rates as low as you can for the application helps and an oil cooler and baffled oil pan with a minimum of 6 qts sure won,t hurt

Developed by one of the top NASCAR Winston Cup Engine Builders, this innovative new tool precisely grooves the lifter bore to ensure that pressure fed oil is directly injected into the contact area between lifter and camshaft. This increased oiling significantly reduces wear on the camshaft and lifters and decreases the risk of premature failure during break in. This machining operation to the block is quick, easy, inexpensive and is the best insurance for a new camshaft. The replaceable carbide cutters are also available separately. Comes complete with grooving tool, cutter and handle.

Note: The engine must be disassembled to use this tool. cuts groove from .009" to .012".

OIL pressure you see on the gauge, is the way you measure the RESISTANCE to oil flow rates , as oil heats up its VISCOSITY drops making it far easier to pump thus the RESISTANCE level drops reflected in the lower gauge readings, 20-25 psi at idle once the engine reaches operational temps is IDEAL

oilvis2.jpg ... ?id=200746 ... ad&A_id=64
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btw common mods that help on both the BBC and SBC


cutting a groove in your lower distributor oil band in-line with the beginning contact point between the gears meshing will provide extra oil flow to the gears but having compatible materials and clearances will be critical, your cam manufacturer will know the correct distributor gear material to use.

drill a .040 hole in the pass side oil passage plug to supply a stead stream of oil to the timing chain



from chevy high performance mag



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hey GRUMPYVETTE??, i have a NEW BUILT 406 in a stock car (MONTE) and oil pressure is connected at block by dist. when at idle it reads 26lbs but at throttle it goes down to zero..7 quart pan with 20 50 oil and have gone thru two guages...any help? can i relocate my pressure to oil filter?

wait, stop right there

don,t assume the gauge or the sensors defective!

that is a very common SYMPTOM, or INDICATION, of a fairly common problem, that's usually the result of the oil pump pick-up being mounted too close to the oil pan floor, at low rpms, theres just enough flow to maintain oil pressure but as the rpms increase your flow into the pump quickly becomes restricted and oil pressure drops to zip, but returns when the rpms fall.
remember as the rpms increase so does the amount of oil being pumped.
oil pressure is the measure of restriction to flow on the pressure side of the pump, in the blocks oil passages, restrict the flow into the pump and pressure falls rapidly.
if you have a massive internal oil leak such as would result from a oil passage plug falling out pressure is reduced significantly but still goes up with the rpms, but restrict the pumps intake and it falls with rpm increases



you must verify theres a MINIMUM or 3/8" under the oil pump pick-up to pan floor.

this is especially common if you've installed a high volume oil pump, because the pumps longer and the oil pump pick-ups moved about 3/8"-1/2" closer to the oil pan floor , this results in that restriction to flow with some pick-up screens if you don,t verify the clearance, or if the pick-up moves due to vibration if you fail to braze it to the pump, this is the source of the MYTH that high volume oil pumps pump the pan dry, when in fact theres plenty of oil in the pan, its just not accessible due to clearance/flow restriction issues



TALLER GEARS SWEEP 25% more OIL per revolution
this simply means you reach the same oil flow rates at a 25% lower rpm,with the hv pump or it takes the standard pump 25% higher rpms to pump exactly the same oil volume ,the pump internally bye passes oil once the bye-pass circuit pressure spring is over come


TALLER gears MAKE the pump body sit lower in the oil pan, if the stock pick-up was 3/8" from the pan floor, swapping to the longer pump body places it about ON the pan floor with many oil pan designs and it WILL severely restrict oil flow into the pump,if its that close to the pan floor and if you don,t change the pick-up that means the pan floor to pick-up clearance is MARGINAL to critical if the pumps changed from the standard to the high volume oil pump

Oil Pumps: The Heart of the Engine

By Larry Carley

Larry Carley

The oil pump is literally the heart of an engine’s lubrication system. It sucks oil in from the crankcase and pushes it through the filter and oil galleries to the crankshaft and camshaft bearings. A constant supply of oil is needed to support and cool the bearings. If for any reason the pump cannot keep the oil circulating it’s the end of the road for the engine.

An oil pump failure is just as bad as cardiac arrest because the results are almost always fatal. Loss of oil pressure means loss of the protective oil film between the bearings and their journals. With no oil to keep the surfaces apart, the bearings wipe and fail.

A worn oil pump can’t deliver the same volume of oil as a pump with normal clearances. With less flow, there’s less oil pressure, less oil to maintain the oil film in the bearings and less cooling for the bearings. Under heavy load or at idle, there may not be enough oil flow to keep the bearings adequately lubed. The result is wiped bearings and engine failure.

Nothing Lasts Forever
A brand new oil pump is engineered to last the life of the engine, which on late model cars and light trucks is typically 150,000 miles or more. But like any other mechanical component the pump is subject to wear. In fact, the oil pump experiences more wear than most other engine parts because it is the only internal engine component that runs on unfiltered oil.

Think about it. The filter protects the bearings and other internal engine parts by trapping wear particles and debris that end up in the crankcase. But the filter provides no protection whatsoever for the pump because the filter is located after the pump. The oil pump just sucks up whatever is in the crankcase and pushes it along to the filter. The only protection for the pump is a screen at the end of the pickup tube. The screen can stop big chunks of debris but little else. Some pickups even have slits that allow cold oil to bypass the screen when the engine is first started, so if there’s any junk in the oil it will be sucked right into the pump.

Pump failure can occur if anything large enough to jam the gears or rotors enters the pump. This includes metallic debris from bearings or castings, gasket or seal debris, shot peening remnants, glass beads from bead blasting, or anything else that doesn’t belong in the crankcase. With twin-gear pumps, a foreign object that enters the pump can lodge between the close-fitting gears or the gears and housing causing the pump to lock up. Once the gears stop turning, something has to give. Usually the pump shaft twists or shears off. Sometimes a pump seizure tears up the teeth on the camshaft or distributor drive gears depending on how the pump is driven. With front mounted rotor style pumps, debris usually won’t lock up the pump because it is driven directly off the crankshaft, but it can damage or destroy the rotors.

Even if a pump doesn’t fail, it loses efficiency as it wears. Over time, the effects of pumping unfiltered oil takes a toll. Scratches and wear in the gears and pump housing increase clearances and reduce pumping efficiency. The result is a gradual loss of oil flow and oil pressure.

An oil pump, by the way, does not create oil pressure. It pushes oil from one place to another. It is a positive displacement pump that moves oil every time it turns. Oil is incompressible so once it leaves the pump it continues to flow until it encounters resistance in the filter, oil galleries and bearings. It’s the resistance to flow that builds pressure in the oil system. Trying to force oil through a small opening is going to create more resistance and pressure than allowing it to pass freely through a large opening.

A worn pump can’t deliver the same volume of oil as a new pump, so with less flow there’s a drop in oil pressure.

As pressure starts to back up in the oil system, it has to go somewhere. A spring-loaded "pressure relief valve" built in the oil pump (or next to the pump) opens when pressure exceeds a certain limit (typically 50 to 60 psi) and either reroutes oil back into the pump’s inlet or the oil pan. This prevents a dangerous buildup of pressure that could rupture the oil filter or blow out press-fit oil plugs.

At idle, most oil pumps do not produce enough flow to force open the relief valve. Oil pumps that are camshaft driven only turn at half engine speed so output isn’t great at idle and low rpm. Even pumps that are crankshaft driven and turn at engine speed (or double engine speed in a few instances) don’t pump enough oil to overcome the relief valve spring. The relief valve generally only comes into play at higher rpms when the pump’s output pushes more oil into the system than it can handle. Then the relief valve opens to vent oil and limit maximum oil pressure until engine returns to idle or a lower rpm.

Vehicle manufacturers have traditionally recommended a minimum of 10 psi of oil pressure for every 1,000 rpm of engine speed. Using these numbers, most stock engines don’t need any more than 50 to 60 psi of oil pressure. With tighter bearing clearances, pressure goes up requiring less flow from the pump and less parasitic horsepower loss to drive the oil pump.

In racing applications, the old school of thought was more oil pressure was needed to keep the engine lubed. That’s true if bearing clearances are loosened up. But most engine builders today tighten clearances so less oil flow is needed to maintain adequate oil pressure. This approach increases the horsepower output because less power is needed to drive the pump at high rpm.

According to various sources, a stock oil pump is usually more than adequate for modified stock block performance engines. NASCAR engines typically get by just fine with no more than 50 psi of oil pressure at 9,000 rpm! Some top fuel dragster and funny car engines are set up so the oil pump will dump excessive oil pressure at high rpm so more power will be routed to the rear wheels.

High Volume/Pressure
In applications where more oil flow is desired either to increase oil flow and pressure for better bearing lubrication and cooling, an oil pump with longer or larger gears may be installed. The physically larger surface area of the gears pushes more oil through the pump at the same rpm as a stock pump. A high volume oil pump typically flows 20 to 25 percent more oil than a stock pump. The increase in oil flow produces an increase oil pressure at idle, which helps compensate for increased bearing clearances. Consequently, some people may install a high volume pump in a high mileage engine in an attempt to restore normal oil pressure. But oil isn’t metal, and the only real cure for low oil pressure is to replace worn bearings and restore normal clearances.

High pressure oil pumps are another option. A high pressure pump contains a stiffer relief valve spring that does not open until a higher pressure is reached (75 psi or higher). The actual flow rate of a high pressure pump may be no different than a stock pump, or it may be higher if longer gears are used. Either way, the pump will increase the system oil pressure reading at high rpm when the pump is working hard, but it won’t have any effect on idle pressure when the pump is turning slowly.

A high volume or high pressure oil pump may be recommended in engines where bearing clearances are looser than normal, in engines where an auxiliary external oil cooler has been added to improve oil cooling, and in racing engines where a oil accumulator has been installed.

Rebuild or Replace?
When a high mileage engine is being remanufactured, you have the option of rebuilding or replacing the oil pump. No engine builder in their right mind is going to risk a warranty return by reusing a worn pump in a rebuilt engine, so most simply replace the pump. According to Melling Engine Parts, a major supplier of oil pumps and repair kits, most engine builders today replace pumps rather than rebuild them because installing a new pump is quicker, easier and less risky.

Replacing the gears in a twin-gear pump can restore gear-to-gear clearances but not gear-to-housing clearances. The end plate that covers the pump often develops a heavy wear pattern that is most noticeable on the outlet gear side. Regrinding the face of the plate smooth can restore end play tolerances between the plate and gears but it can’t compensate for wear in the housing. Deep scratches or grooves worn into the sides of the housing will leak oil and reduce the pump’s ability to move oil.

In the case of front cover oil pumps on overhead cam engines, the pump turns at engine rpm and generates more flow at idle than crankcase mounted pumps. Consequently, when the pump becomes worn it isn’t always necessary to replace the entire cover assembly – provided the pump housing inside the cover isn’t worn or damaged. A new drive gear can be mounted on the crankshaft and a new rotor installed in the cover to restore normal oil pressure. This approach can usually save you 50 percent or more over replacing the entire cover assembly.

In cases where an engine has experienced a bearing failure or any other kind of internal failure that puts debris into the crankcase, the oil pump should always be replaced.

Another item that should always be replaced (but often isn’t) is the pickup tube and screen. Pickups are difficult to clean and can hide debris that may damage a new pump or the the engine.

Pump Modifications
Performance engine builders will often rework the inlet and outlet ports of a stock oil pump housing to eliminate sharp edges that restrict oil flow. Using a die grinder to smooth and blend the sharp edges of the ports will enhance flow in and out of the pump. The clearance between the end of the gears and the pump housing cover should also be minimized to reduce pumping losses.

Some engine builders also install big block Chevy oil pumps on small block Chevy engines to increase oil flow. A stock big block Chevy oil pump has 12 teeth per gear versus 7 for the small block version, and flows about 10 percent more oil at the same rpm.

Something else to watch out for when installing a high volume oil pump in a small block Chevy V8 is the nylon retainer on the pump shaft. A better choice would be a pinned steel retainer to provide extra support between the intermediate shaft and pump shaft.

Care must also be used when tightening down the pump mounting bolts on small block and big block Chevy V8s because the pumps do not use a mounting gasket. The bolts should be torqued to 60-70 ft. lbs. so there are no leaks or sloppiness that would eventually cause the shaft to break.

Reducing Warranty Issues
The greatest oil pump in the world won’t keep an engine properly lubed if it is dry when the engine is first started, or it if sucks air because the oil level in the crankcase is low or the pickup screen is mounted too far above the floor of the oil pan.

The pickup tube should be installed so it is located no less than 3/8˝ above the floor of the oil pan (to allow good intake flow), and no more than 1/2˝ above the floor so it doesn’t run out of oil in a sharp turn.

The pump should also be filled with oil when it is mounted on the block to prime it and reduce the risk of a dry start. Do not use grease or assembly lube here. In the case of front mounted oil pumps inside the timing cover, the pump rotors can be coated with heavy oil such as 50W or even gear oil to keep the pump primed.

You should also attach a yellow or red tag on the engine warning the installer to prime the oil system with a pressurized oiler before cranking or attempting to start the engine. Oil tends to drain off bearing surfaces when an engine sits for more than a week or so without running. So if an engine has been sitting in a warehouse for a month or more before it is installed in a vehicle, you can bet the bearings are going to be dry unless they were precoated with a long-lived assembly lube.

On older engines with distributor driven oil pumps, the engine can be primed by using a drill to spin the oil pump shaft through the distributor hole. But on engines with no distributor or those with oil pumps inside the front cover, this isn’t possible. Feeding pressurized oil into the main oil gallery through the oil pressure sending unit fitting will route oil to all the critical areas inside the engine and eliminate the risk of scuffing the bearings when it is first started.

New Oil Pump Program
Vern Schumann of Schumann’s Sales & Service in Blue Grass, IA, said his company is launching a brand new oil pump program that will be sold under the Manley brand name. The new line will eventually include twelve of the most popular oil pumps, starting with four pumps in February. "Our goal is to create a quality program that will grow at its own rate, probably one pump a month," said Schumann.

"Our first applications will be for small block Chevy V8s and short deck 289/302 Windsor Ford V8s. The numbers are 55, 55HV (high volume), 55HV Racing, and 68."

Schumann said one of the advantages of launching an entirely new pump program from scratch is that he is not locked into any existing designs. Consequently, gear tolerances and relief pressures can be optimized for the aftermarket.

"Our 55 pump, for example, will have a kick out pressure of 60 psi, which is on the high end of the specifications. When engines are rebuilt, customers never complain about too much oil pressure. They typically complain about too little oil pressure. On small block Chevys with hot thin oil in the crankcase and a 200 degree thermostat, it’s common to see only about 10 to 15 psi of oil pressure at idle on the oil pressure gauge – which is not very reassuring. So we’re minimizing clearances to reduce pumping losses and to maximize oil flow at idle.

"Another problem with most relief valves is that the side of the valve as well as the end is exposed to oil pressure. This produces a sideways thrust that can cause the valve to hang up halfway in the bore. Our relief valves are redesigned so pressure is only applied to the end of the valve."

Schumann said improving machining accuracy and reducing tooth-to-tooth tolerances and gear-to-housing tolerances maximizes oil pressure at idle. "Something else you have to watch is the finish on the pedestal pads because this affects the end play of the pump gears. You don’t want any chatter marks on the pads because it will increase end play and cause a loss of pressure. Our pumps have .002˝ of end play and will stay that way because there are no chatter marks to wear away."

As for pricing, Schumann said his pumps will be competitively priced somewhere between the old DynaGear prices and those of the other major aftermarket suppliers.




if the oil flow came through the push rods as you primed the engine, in that order your rear cam bearing may not be correctly indexed/installed incorrectly, BOTH the front and rear cam bearings feed oil across to the other lifter gallery when the front and rear cam bearings are correctly indexed to the lifter gallery oil feeds






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Most of the stock automobile engines are designed to operate from idle to 4500 RPM. The original volume and pressure oil pump will work fine in this type of application. As the demands on the engine increase so does the demands on the oiling system and pump.
The oil pump's most difficult task is to supply oil to the connecting rod bearing that is the farthest from the pump. To reach this bearing, the oil travels from three to four feet, turns numerous square corners thru small holes in the crankshaft to the rod bearing. The rod bearing doesn't help matters. It is traveling in a circle which means centrifugal force is pulling the oil out of the bearing.

A 350 Chevy has a 3.4811 stroke and a 2.111 rod journal. The outer edge of the journal travels 17.5311 every revolution. At 1000 RPM, the outer edge is traveling at 16.6 MPH and 74.7 MPH at 4500 RPM. If we take this engine to 6500 the outer edge is up to 107.9 and at 8500 it is 141.1 MPH. Now imagine driving a car around a curve at those speeds and you can feel the centrifugal force. Now imagine doing it around a circle with a 5.581, diameter.

The size of the gears or rotors determines the amount of oil a pump can move at any given RPM. Resistance to this movement creates the pressure. If a pump is not large enough to meet the demands of the engine, there will not be any pressure. Or if the demands of the engine are increased beyond the pumps capabilities there will be a loss of oil pressure. This is where high volume pumps come in; they take care of any increased demands of the engine.

Increases in the engine's oil requirements come from higher RPM, being able to rev faster, INCREASED BEARING CLEARANCES, remote oil cooler and/or filter and any combination of these. Most high volume pumps also have a increase in pressure to help get the oil out to the bearings faster.

That is what a high volume pump will do. Now lets consider what it will not do.

It will not replace a rebuild in a worn-out engine. It may increase pressure but the engine is still worn-out.

It will not pump the oil pan dry. Both solid and hydraulic lifters have metering valves to limit flow of the oil to the top of the engine. If a pan is pumped dry, it is because the holes that drain oil back to the pan are plugged. If the high volume pump is also higher pressure, there will be a slight increase in flow to the top.

It will not wear out distributor gears. The load on the gear is directly related to the resistance to flow. Oil pressure is the measure of resistance to flow. The Ford 427 FE "side oiler" used a pump with relief valve set at 125 psi and it used a standard distributor gear. Distributor gear failures are usually caused by a worn gear on a new cam gear and/or worn bearings allowing misalignment.

It will not cause foaming of the oil. With any oil pump, the excess oil not needed by the engine is recirculated within the pump. Any additional foaming is usually created by revving the engine higher. The oil thrown from the rod bearings is going faster and causes the foaming. This is why high performance engines use a windage tray.

It will not cause spark scatter. Because of the pump pressure there is a load on the distributor gear. The number of teeth on the oil pump gears determine the number of impulses per revolution of the pump. In a SB Chevy there are seven teeth on each gear giving 14 impulses per revolution. At 6000 RPM the oil pump is turning 3000 RPM or 50 revolutions per second. To have an effect on the distributor, these impulses would have to vibrate the distributor gear through an intermediate shaft that has loose connections at both ends. Spark scatter is usually caused by weak springs in the points or dust inside the distributor cap.
different blocks and bearing locations have slightly different configs,
obviously if theres no oil feed groove under the bearing the oil feed holes must align with the oil feed passages,
with the block in the upright position the cam bearings are fed,
from the upper central cam, or lifter gallery oil passage, look at the diagrams
most cam bearings come with instructions and diagrams.
and yeah it generally helps to look at the old cam bearings and oil feed hole locations, take notes and in most cases re-install the new bearings in a similar fashion.
chevy V8 cam bearings are NOT universally interchangeable between locations












carefully measure the old cam bearings and pay attention to oil feed hole locations
the bearings are not universally interchangeable and yes size varied


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" GRUMPY I want to install a big block stroker in my 1959 corvette, after careful measuring I find the main issue may well be oil pan to ground clearance, any suggestions "

measure from the block oil pan rails down to the bottom of your current oil pan, the stock oil pump extends down to about 7.2" so a 7.5" oil pan sump is about the limit on a WET SUMP system,with the stock oil pump, but if your willing to go DRY SUMP oiling with a side mount belt driven oil pump like many serious race applications use, you can get that closer to 6" deep. a remote oil cooler and remote mount oil filters might help with clearance and an oil accumulator might be useful.










IF you've wondered why I suggest buying and using a well designed BAFFLED oil pan with 7-8 quart capacity its to prevent the oil from uncovering the oil pump pick-up under performance use.
without control baffles oil sloshes away from the oil pump pick-up



Slosh2.jpg ... 2/10002/-1 ... P4092.aspx ... rettyPhoto
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Casey said:
i Verified the cap was in place IN THE OIL PASSAGE..... Pulled the front cover and slid the cam forward enough to use a borescope and cam bearings are good. Buttoned it all backup, I replaced oil filter and primed it.NOW I Have 70 psi on the gauge with a 3k rpm drill. Taking the pressure at the port next to the dizzy, not above the oil filter. I Have to replace a freeze plug UNDER THE MAIN CAP before I can run it and check final pressures. Since the plug next to the dizzy is the final point in the oiling system, how different would it be vs the port above the OIL filter?

Pressure is a measure of resistance to flow, if your measuring 70psi at one point in the oil passage the other end should be nearly the same reading
points A,B,C should be very similar pressures, the only reason they are not IDENTICAL is because the oil system in a small block has about 100 points where oil seeps out under pressure thru bearing clearances etc. I doubt you can measure the difference with automotive gauges
16 lifter to push rod points
16 push rod to rocker arm points
32 lifter bores 16 x 2 ends
10 main bearing edges
9 cam bearing edges
16 rod bearing edges
2 distributor shaft leaks
1 distributor shaft to shim above the cam gear(some engines that have an oil pressure feed distributor shaft bearing.)


"Pascal's law states that when there is an increase in pressure at any point in a confined fluid, there is an equal increase at every other point in the container."

read thru these links ... forman.pdf ... ooving.pdf


TB 2051 2/10/2000
Influence of Grooving on Main Bearing Performance
Various forms of main bearing grooving have been used over the years. We are
frequently asked what difference grooving makes.
First, it’s essential to understand that bearings depend on a film of oil to keep them
separated from the shaft surface. This oil film is developed by shaft rotation. As the shaft
rotates it pulls oil into the loaded area of the bearing and rides up on this film much like a
tire hydroplaning on wet pavement. Grooving in a bearing acts like tread in a tire to break
up the oil film. While you want your tires to grip the road, you don’t want your bearings
to grip the shaft.
The primary reason for having any grooving in a main bearing is to provide oil to the
connecting rods. Without rod bearings to feed, a simple oil hole would be sufficient to
lubricate a main bearing. Many early engines used full grooved bearings and some even
used multiple grooves. As engine and bearing technology developed, bearing grooving
was removed from modern lower main bearings. The result is in a thicker film of oil for
the shaft to ride on. This provides a greater safety margin and improved bearing life.
Upper main shells, which see lower loads than the lowers, have retained a groove to
supply the connecting rods with oil.
In an effort to develop the best possible main bearing designs for High Performance
engines, we’ve investigated the effects of main bearing grooving on bearing performance.
The graphs on the next page illustrate that a simple 180
groove in the upper main shell is
still the best overall design.
While a slightly shorter groove of 140
provides a marginal gain, most of the benefit is to
the upper shell, which doesn’t need improvement. On the other hand, extending the
groove into the lower half, even as little as 20
at each parting line (220
in total), takes
away from upper bearing performance without providing any benefit to the lower half.
It’s also interesting to note that as groove length increases so do Horsepower Loss and
Peak Oil Film Pressure which is transmitted directly to the bearing
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Jolle said:
Hi, just recently overhauled my 427 engine and upon start-up (or actually 200 km) it started to leak in one of the oil galley plugs (side plug closest to the enegine mount on the drivers side. Now I hope that someone of you experts can advice me how to stop this leak.
1. Can I re-tighten the plug without breaking the thread sealant.
2 If I need to remove the plug and re-seal with proper sealant, will I need to re-prime the oil prior to start-up, having in mind air now being in the oil galley?
a well supported oil pump pick-up tends to cause far fewer issues than one that cab flex and vibrate as metal fatigue can eventually cause them to break


BRAZING IS ALWAYS A GOOD IDEA,(just be sure to remove the bye-pass circuite parts and verify function when reinstalled)

vibration can and does occasionally cause pick-up failures
broken oilpickup.jpg

Im new at this, as you may see on my questions, but I would really appreciate your input here as I dont want to make things worse by doing wrong. Thanks in advance..




heating the plugs with a torch then rapidly cooling them with this FREEALLOIL HEAT AND spray a few times in rapid succession usually frees them up to spin out with far less resistance to the wrench applied torque

order a couple cans, trust me youll order one and feel like an idiot when it runs out and you don,t have any left




just back out the leaking plug,from the lower blocks oil passage on the side of the block, clean it carefully coat with the proper sealant and re-install then prime the oil system to test for no leaks

there will be other factors at play

when your installing something similar to this engine, the stock fuel lines and fuel pump were never designed to keep up or provide adequate flow


AN#8 or 1/2" internal fuel diam. size lines and a 120-140 gal per hour pump (general rule is the fuel pump should have a rating of a minimum of 150% of the engines minimum requirements to compensate for the inevitable flow restriction losses in lines and fittings and inertial loads during acceleration) would meet your engines requirements, the 5/16" fuel tank connection will be a big restriction, and you should use a return style fuel pressure regulator and a AN#* ideally, but AN# 6 - 3/8" MINIMUM return line, and a fuel pressure regulator that has 1/2" inside diam,diam fuel line fittings(


Ive found that if you select a decent quality radiator , like the 3 or four tube high fin count designs,equipped with a matching fan and fan shroud,
your generally fine with a 1.7-2 square inch of frontal surface area per horsepower, if you had a 700 hp engine this will rather obviously pose a problem,as a bit of quick math will obviously show theres not nearly enough surface area for ideal engine cooling, as most muscle car radiators are in the 400-500 square inches of surface area range (18"-19"tall and 24"-30" wide), so adding oil coolers, transmission fluid coolers and very effective fans that increase the cooling capacity are generally required.
adding high efficiency fans and shrouds boosts heat transfer rates,but youll rapidly find just a radiator won,t tend to be adequate in heavy traffic and low speed driving on hot days,unless your very careful with a multi level cooling system design, the stock radiator would rapidly prove it was inadequate.


larger capacity oil and trans fluid coolers with power fans can remove a good deal of the heat load an engines cooling system would otherwise be burdened with.
having a large capacity oil and transmission fluid cooler separate from the engine coolant radiator, increases the surface area the air flow through the additional fan equipped fluid coolers , ideally mounted around the car rather than stacked in front of the cars radiator has the desired and more effective use of that air flow to transfer that heat with.
remember your oil and lube system are used to absorb and transfer a great deal of the engines heat from moving parts before the coolant comes into play, so constantly cooling the engines internal lubricating oil flow pays off in reduced engine temps.

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