oil pump drive shafts

grumpyvette

Administrator
Staff member
I was asked recently, as to my best guess, as to why a recently installed oil pump was making noise,
oil pumps rarely make much noise, unless, the drive shaft driving the oil pump, is rubbing on the block which will happen if you install a standard drive shaft in a 400 type small block which requires the drive shaft with the smaller diameter midsection. (what was going on in this case) Or you forget to install that little metal or nylon collar that keeps it aligned, or if your drive shaft has one the little spring clip, and remember to install the shaft along with the oil pump from below because the collar is designed to be too large to pass thru the block passage above it to insure the drive shaft stays attached to the oil pump. remember if the clearances inside the oil pump are not checked, and is partly binding or in some cases of the oil pump has ingested, some small bits of metal or other foreign material. the pump might be damaged, the standard high-performance oil pump drive shaft looks like the one below ,it has a steel collar and is made from a stronger than normal steel
heres a standard volume BBC oil pump which can be used in a small block high performance application provided its matched to the correct oil pan and oil pump pick-up of course.
REMEMBER once the oil pumps installed on the main cap and the distributors test fitted on the intake manifold there should be about .050=.060 vertical clearance remaining on the oil pump drive shaft between the oil pump and distributor with the distributor firmly seated on the intake manifold and at least .060 in all directions around the oil pump drive shaft, "CHECK THE COLLAR" in rare cases it binds

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http://m.summitracing.com/parts/mel-m77

http://m.summitracing.com/parts/mel-77060

chevy oil pump drive shafts come in several lengths and styles and some have metal or nylon collars, you should select the oil pump drive shaft that allows about a .050-.060 thousands clearance between the oil pump and distributor when the distributors seated on the intake manifold
its not uncommon for distributor gears and cam gears to not be perfectly lined up as to depth of the distributor or length of the oil pump drive, theres several different pump drive shaft lengths and spacer shims but in many cases a slip collar on the distributor or modifying the oil pump drive shaft will be required to get perfect alignment

your current distributor can usually be easily modified by a local machine shop with a lathe for an adjustable slip collar by carefully machining off the current one and adding a slip collar, if you need to make distributor gear to cam gear engagement or oil pump drive shaft length changes
MOR-26217_QQ.jpg

http://www.summitracing.com/parts/MOR-26217/?rtype=10
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viewtopic.php?f=54&t=2187&p=5890#p5890
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adding "ST" to the end of the existing melling part number denotes the helical gear set option


bracing the oil pump with a milodon vibration brace can increase durability
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make sure the oil groove lines up with where the gears mesh when the distributors installed and timed correctly.
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btw a long blade screw driver will allow you to index or rotate the oil pump drive shaft to any location you choose, too allow the distributor to fully seat
Its smart to file a small groove in the lower distributor so oil spray from the oil passage constantly lubricates the distributor gear to cam gar contact point

the standard non- reduced mid section type oil pump drive shaft should never be used in a 400 type blocks, and I don't use them on any engine builds
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the ARP style with the reduced cross-section of metal is the preferred type, when you do get around the checking the clearances between the gears of the oil pump, and a removable floor plate, the end play clearances should be no more than .003 maximum, .002 preferred, you'll see one driven gear and one drive gear, I normally pull off the driven gear and carefully drill of the 1/16 inch holes in the bottom of the gear tooth slot, at three places spaced vertically, and horizontally one third of the way around an up-and-down on those seven to 12 gear teeth have(depends on the pump your using) if done correctly and carefully this modification at least in theory aids the oil flow sporting that driven gear, as in most engine mods, no one thing does tell a lot, but the accumulation of a lot of little things and modifications, makes for a winning engine combination.
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READ THIS LINK
viewtopic.php?f=70&t=251&p=1366#p1366

theres a difference between the sbc and bbc drive shaft designs so don,t mix them up
The bottom of a Chevrolet distributor housing can be modified to spray pressurized oil onto the distributor drive gear. The extra lubrication will reduce distributor gear and camshaft gear wear. This is especially important when the gear is used to drive non-standard accessories, such as a high volume oil pump, or a magneto that puts additional loads on it and the cam. When the distributor is installed, the bands at the bottom of the housing are designed to complete the internal right side lifter galley on all small and big block Chevrolet V-8s and 90° V-6 engines. If you hand file a small vertical groove .030" wide x .030"( thats the diam. that crane recommends Ive always used the larger groove with no problemsdeep on the bottom band (above the gear), pressurized oil running between the two bands will be directed downward onto both the gear and the camThis procedure is recommended for all Chevrolet engines no matter what material gear (cast or bronze) or what type of camshaft (cast or steel) you are using
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keep in mind the groove MUST be lined up with the cam gear when the distributor. is installed
another potential source of problems and noise that you should but know about is that, YOU must always install and aluminum bronze distributor gear on a steel cam normally these are roller cam's than normal distributor gear is made of what looks like cast-iron will not work on a steel roller cam a steel roller cam will quickly destroyed a standard gear that's why you must use the aluminum bronze gear.... unless , the steel cam has had pressed on cast-iron gear to match the standard distributor gear.
almost every sbc engine I build uses a standard volute big block pump or a high volume standard pressure oil pump with no problems at all, my 383 in my 1985 vette gets pulled out and checked , new rings and bearings just as a standard rebuild about every 18 months and not once has either the distributor. or cam gear show excessive or for that matter even measurable wear, the fact that I run a 9.5qt oil pan, with magnets that pick up all metallic dust, good oil filters, and 90% plus synthetic oil, a groove in the lower distributor oil band, that sprays a constant stream of oil onto the contact point I think is the main factor READ THIS http://www.melling.com/highvol.html http://www.melling.com/engoil.html http://www.melling.com/miscon.html
now think it thru,
(1)pressure is the RESULT of resistance to oil flow
(2) the high volume pump can push about 25% more oil
(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 all additional oil volume
(4) the engine can accept and use only the max flow volume that the engine passages 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 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 SO...
(7)all a high volume 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 THE idle-6000rpm range but if rpm levels exceed 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
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the oil pump drive and gears can benefit from extra oil flow mods

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read thru this threads





http://www.moroso.com/catalog/pdf/Oil_Pumps_106.pdf
 
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don't ignore links

if your distributor won,t seat on the manifold and gasket the oil pump drive shaft may need to be shortened (thats the correct route)or theres distributor shim gaskets

http://garage.grumpysperformance.co...ke-manifold-distributor.464/page-2#post-39647

viewtopic.php?f=54&t=123&p=326#p326

http://www.stockcarracing.com/techartic ... tallation/

http://www.summitracing.com/parts/mor-26150
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they are installed from the pump side of the block , the pump being bolted in place keeps it from dropping out below and the collar on the shaft won,t allow it to slide upward more than a minimal amount. keep in mind the distributor to oil pump drive shaft vertical clearance must have about .020- .050 clearance or it binds

once you get the distributor clamped down in place on the intake that's installed,on your engine , you'll need to verify that theres some remaining vertical oil pump drive shaft clearance in the distributor or you'll destroy the pump or distributor shaft bearings in short order, they can,t be bearing tightly against each other ,you should still be able to lift the distributor driven oil pump drive shaft, and lower it in the space between the distributor and oil pump about .040 thousands or theres a problem, that needs to be addressed, the distributor drive to the oil pump shaft length will need to be shortened a few thousands to prevent binding, failure to leave some slack will result in component failure, the distributor shaft itself needs to be shimmed for minimal movement in the distributor body, see the link posted below
,

viewtopic.php?f=70&t=251&p=299&hilit=shims+distributor#p299

did you replace the oil pump drive shaft?
theres three common lengths in those oil pump drive shafts
theres a difference in length between the drive shaft used for a common sbc oil pump,
the drive shaft used for a BIG BLOCK oil pump in a SMALL BLOCK APPLICATION,
and a BIG BLOCK oil pump drive shaft length
all can be placed in a small block,or a big block but only the correct length will function in each application

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http://www.msdignition.com/Products/Dis ... butor.aspx

theres a difference between the sbc and bbc drive shaft designs so don,t mix them up
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the "shroud" or tubing like lower section slides over and keeps the oil pump drive perfectly aligned with the oil pump gear drive shaft in the pump, it also tends to prevent the EARS on the oil pump drive from getting bent, just as the upper end does by sliding into the distributor drive gear
the stock non-guided oil pump drive shaft tends to bind slightly in some applications
keep in mind that the 400 SBC has a larger main bearing diameter and REQUIRES a drive shaft thats a bit smaller in mid section diameter to clear the internal block s casting near the main crank bearing to obtain the proper alignment, and that means that a drive shaft designed for a 350 will tend to rub or not allow the distributor to seat without binding the shaft, so use the slim center section ARP shaft with a tempered steel shaft on 400 block based builds
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there should be about vertical .050- .060 play in the oil pump drive with the distributor clamped in the intake
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your current distributor can usually be easily modified by a local machine shop with a lathe for an adjustable slip collar by carefully machining off the current one and adding a slip collar, if you need to make distributor gear to cam gear engagement or oil pump drive shaft length changes
MOR-26217_QQ.jpg

http://www.summitracing.com/parts/MOR-26217/?rtype=10


READ THIS

viewtopic.php?f=52&t=57&p=70&hilit=pump+drive+shaft#p70
http://www.msdignition.com/uploadedFile ... ctions.pdf
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http://www.jegs.com/i/Mallory/650/29003 ... tId=750253
If you decide to use a crank trigger /magnetic pick-up trigger ignition , you generally won,t be using a typical distributor, this is sometimes required when the intake system is making installing a common rear distributor difficult due to limited room at the rear of the engine, a fairly typical condition with some tunnel ram or injection induction systems, but because the distributor drives the oil pump on a chevy your forced to make a substitute oil pump drive.
yes MALORY makes an direct full length, oil pump drive to replace the distributor's lower section in first gen chevys if you choose to use a crank trigger ignition with a magnetic pick-up on the flywheel or DAMPER
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If you have a lt1 block you of course already have that replaced due to the opti crap ignition, notice the short LT1 oil pump drive bolts under the intake to the block casting, these are available in metal or plastic, obviously plastic is weaker and there's NO HOLE IN THE LT1 INTAKE, for a distributor in most versions notice the full length mallory version is a direct distributor replacement REQUIRING the hole in the intake to be alined and bolted, into place
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grumpyvette said:
once you get the distributor clamped down in place on the intake that's installed,on your engine , you'll need to verify that theres some remaining vertical shaft clearance in the distributor or you'll destroy the pump or distributor shaft bearings in short order, they can,t be bearing tightly against each other ,you should still be able to lift the distributor shaft, and lower it in the distributor body about .040 thousands or theres a problem, that needs to be addressed, the distributor drive to the oil pump shaft length will need to be shortened a few thousands to prevent binding, failure to leave some slack will result in component failure
Seems like that .040" end play would be for the oil pump drive-shaft, instead of the distributor shaft. I measured the end play on my new MSD 8360, it was .015". Wouldn't erratic timing be possible with the larger end play on the distributor shaft.

grumpy, no mater how hard I tighten the distributor clamp on my intake manifold,
I will almost enviably, find its moved and will require re-timing. any ideas?

Ive seen this frequently, and almost always its a case where if you measure carefully, youll almost surely find,
the oil pump drive shaft is bottoming out solidly between the oil pump and the distributor gear is binding,
so the distributor is not firmly seated against the intake manifold surface.
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the oil pump drive shaft length MUST BE about .050 SHORTER than the distance it would take to firmly seat it inside the distributor drive gear, the cam has a gear that spins the distributor and the oil pump drive shaft is driven by that distributor gear in the lower distributor that extends down to the oil pump drive.


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this gear must not bind on the distributor too oil pump drive shaft when the distributor is seated firmly on the intake manifold and clamped into place there must be about .050 clearance minimum
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ctrp_0606_gear_01_z+distributor_installation+camshaft.jpg

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related threads you should really read

http://garage.grumpysperformance.com/index.php?threads/oil-pump-drive-shafts.123/

http://garage.grumpysperformance.co...ibutors-wont-seat-on-intake.12538/#post-63636

http://garage.grumpysperformance.com/index.php?threads/oil-pump-drive-shafts.123/#post-19025

http://garage.grumpysperformance.co...ing-an-oil-pump-pick-up-tube.1800/#post-43110

http://garage.grumpysperformance.com/index.php?threads/distributor-gear-wear.1701/#post-4160

http://garage.grumpysperformance.co...butor-clamp-that-just-won-t-clamp-firmly.871/

http://garage.grumpysperformance.co...-allows-the-distrib-to-turn-even-tighten.873/

http://garage.grumpysperformance.com/index.php?threads/setting-timing-question.1411/#post-3131
thanks for pointing out that screw-up,your totally correct thats a stupid typo,brain fart, I was referring to the oil pump drive shaft
it should read

they are installed from the pump side of the block , the pump being bolted in place keeps it from dropping out below and the collar on the shaft won,t allow it to slide upward more than a minimal amount. keep in mind the distributor to oil pump drive shaft vertical clearance must have about .020- .050 clearance or it binds

once you get the distributor clamped down in place on the intake that's installed,on your engine , you'll need to verify that theres some remaining vertical oil pump drive shaft clearance in the distributor or you'll destroy the pump or distributor shaft bearings in short order, they can,t be bearing tightly against each other ,you should still be able to lift the distributor driven oil pump drive shaft, and lower it in the space between the distributor and oil pump about .040 thousands or theres a problem, that needs to be addressed, the distributor drive to the oil pump shaft length will need to be shortened a few thousands to prevent binding, failure to leave some slack will result in component failure, the distributor shaft itself needs to be shimmed for minimal movement in the distributor body, see the link posted below
,

viewtopic.php?f=70&t=251&p=299&hilit=shims+distributor#p299

viewtopic.php?f=54&t=3536&p=9372&hilit=shimming+distributor#p9372

viewtopic.php?f=54&t=6479

"grumpy, Ive been checking things during my engine assembly, Ive got a problem, my distributor doesn,t have an adjustable sliding collar to make the clamp height adjustable and when I seat the distributor its resting firmly on the oil pump drive shaft and still not seated on the intake, so clamping it puts a significant load on the oil pump...now what?"


As Im sure you know the lower distributor body forms one wall on an internal oil passage and the gear on the cam drives the distributor and the internal blade inside the distributor gear is semi interlocked with the oil pump drive shaft.,
Im sure you know the oil pump drive will only slide inside the distributor gear in two locations where the two ears on the oil pump drive line up with the blade inside the distributor gear.

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obviously you can pre align the slot to accept the slot inside the distributor gear in the base of the distributor to allow the distributor get the rotor to face any direction when seated
distre1.jpg

you should be trying to get about a .020-.050 clearance between the fully seated distributor and the oil pump drive shaft,
If you find its the length of the oil pump drive shaft thats preventing the distributor from fully seating, those oil pump drive shafts are available in several lengths and you might need to grind or machine off a bit of length to get the ideal fit/clearance.
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http://www.hawaiiracing.com/?page=shop/ ... 66efce1a0d
THERE ARE slide collars available in the aftermarket for less than $20 and almost any chevy distributor body can be machined to remove the original collar and install a sliding collar. almost any good machine shop with a lathe can do the required mods.

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READ THE RELATED THREADS

viewtopic.php?f=48&t=873&p=1367&hilit=clamp+distrib#p1367

viewtopic.php?f=54&t=6479&p=20555&hilit=pump+drive+shaft#p20555

viewtopic.php?f=54&t=123&p=19025&hilit=pump+drive+shaft#p19025

http://garage.grumpysperformance.com/index.php?threads/sbc-oil-pump-noise.14582/

viewtopic.php?f=32&t=36&p=44&hilit=pump+drive+shaft#p44
 
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