Valve Spring Cooling via Engine Oil



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 from the Pushrods. Also know that the Valve Springs are not getting oil cooling. The engine has little run time on it, yet I want to ensure the the trunions are getting engine oil. Additionally, I have envisioned a spray bar system for cooling the valve springs with Engine Oil. The first thing that would need is to tap the left and right oil galleries and route a hard line up through the cylinder head to a log manifold next to the valve springs. Then off the manifold via squirters onto the valve springs. The squirters should have an opening pinched into a figure 8 pattern, much like windshield washers, such that the oil spray from them would be a vertical fan centered on the individual valve springs.

Would appreciate your thoughts or perhaps another method of cooling valve springs with engine oil. I have a high volume racing oil pan with kick-outs and a High Volume Big Block Oil Pump inside the pan. Also purchased AFR-195 STREET cylinder heads and purchased the heavier duty competition valve springs from AFR and installed them as they have greater open and seat pressure. Also read your comments about using Rev Kit springs. VERY GOOD suggestion as the valve spring could be a BEE HIVE spring, instead of a DUAL STRAIGHT valve spring and reduced possibility of valve train damage.

Looking forward to your response and suggestions.


Rolland Sicard, Tucson Arizona


Staff member
with the fairly low valve spring load rates and average rpms that the stock engines are designed to run with the oil flow from the push-rods flowing over the rockers and down over the valve springs, usually supplies adequate valve spring cooling
but on a performance engine with its higher average rpm and power band the stock oil flow thru the valve train can be marginal, under some would not be the first guy to add , or think about adding spray oil cooling to the valve train, on a street car or drag race car its probably a good deal more work that the mod provides in benefit to the engine but theres no question that in endurance racing its a great idea.
valve springs and rockers that are not constantly bathed in fresh cool oil rapidly heat up, valve springs can reach temps that reduce the spring temper,thus a constant bath in fresh cooler oil is mandatory for loner term durability,
keep in mind both engine oil temps and trans fluid temps seldom reach operational temps,fluid
and stabilize , for semi consistent data,in under 12-15 minutes of drive time,temps have a huge effect on lubricant viscosity and durability. .

many shaft rocker systems have strategically located oil shaft holes that direct flowing oil to the valve springs and rockers.
almost all lubrication oil flow thats cooling the valve train on a stock Chevy V8 flows up thru the push-rods on a Chevy valve train,these links and pictures below and sub linked info may help, keep in mind your forced to deal with the issue of increased heat generated as you increase engine power levels,in the valve train, and engine bearings cooling with a system approach where you first provided increased oil flow on the heated parts to lubricate and absorb the heat then your forced to deal with,transport and remove that higher heat, with an auxiliary oil cooler and oil pan with increased capacity, (and larger remotely mounted oil filters certainly won,t hurt)
look over this picture.
yes an effective oil cooler will reduce engine operating temps 10-15 degrees ,and in some cases dramatically reduce wear , by keeping oil temps low, its lower engine oil temps,that allow the oil to efficiently absorb and transfer the higher stressed and higher heat being generated and higher engine temps to the coolant, its the oil that initially cools the valve train and piston rings and bearings and those areas do produce a good deal of the engines heat, its the oil that transfers much of that heat to the cylinder block and head surfaces where the coolant can absorb and transfer it to the radiator, where its dispersed to the outside airflow.


IM currently using this on my 1985 corvertte but have used others in the past

on endurance applications like circle track or off shore race boats plumbing a separate pressurized spray bar to cool valve springs and rockers that feeds from either a passage in the block or a separate oil pump has proven to be very helpful in long term durability, because the rapid cycling torsional stress on valve springs can easily cause them to heat to over 700F if not bathed in a constant flow of oil that absorbs and carry's away the heat that builds up rapidly, most people don,t understand that almost 1/2 of an engines total heat comes from the valve train and bearing friction





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High Performance Rocker Arms, Valve Springs, Retainers and Locks


hotrod said:
For a dual-purpose car, engine oil needs to be at least 220 degrees F to burn off all the deposits and accumulated water vapor. For every pound of fuel burned in an engine, the combustion process also generates a pound of water! If engine sump temperatures rarely exceed 212 degrees (water’s boiling point), the water will mix with sulfur (another combustion by-product) and create acids that can eventually damage bearings.

As for ultimate power potential, the general consensus among most racers is that hot oil and cool water make more power in most engines. Cold engine oil causes excessive frictional drag on the bearings and cylinder walls. A quality conventional motor oil will tolerate oil sump temperatures of up to 250 degrees, but starts breaking down over 275 degrees. The traditional approach is to try to hold oil temperatures between 230 and 260 degrees. Even on a short-duration, drag-only combo where oil is frequently changed, I would not want to routinely see under-200-degree oil temps.

Larry Carley

Upper valvetrain components have more of an effect on power and reliability than you might realize. Most engine builders know that changing the rocker arm ratio increases valve lift for more power. But did you know that changing the rocker arm pivot point can also reduce friction and the rate at which the valves open and close?

On a small block Chevy, altering the rocker arm geometry without changing the rocker arm lift ratio can add 15 to 20 horsepower at the rear wheels.

The stock lift ratio for a small block (SB) Chevy V8 rocker arm is 1.5:1, and for a big block (BB) Chevy V8, the ratio is 1.7:1. Bolt-on aftermarket high lift rocker arms with higher ratios are often used to get more net lift out of an existing cam profile. The most common high lift ratio upgrade for a SB Chevy engine is 1.6:1 rocker arms, and 1.8:1 rockers for BB Chevys. But some performance rockers now offer ratios as high as 2.0:1 or even higher!

Increasing the lift ratio adds horsepower with little or no loss in low rpm torque, idle quality or vacuum. By opening and closing the valves at a faster rate, the engine flows more air for the same number of degrees of valve duration. High lift rocker arms also reduce the amount of lifter travel needed to open the valves, which reduces friction and the inertia of the lifters and pushrods that must be overcome by the valve springs to close the valves. On the other hand, increasing the rocker ratio also increases the effort required to open the valves because of the leverage effect. The higher the rocker arm ratio, the greater the force the camshaft, lifters and pushrods have to exert to push the valves open. But when the valves close, the increased leverage of the rocker arms works the other way making it easier for the springs to shut the valves and push the rocker arms, pushrods and lifters back to their rest positions.

On SB Chevy engines, the stock stud-mounted rocker arms are supposed to be self-centering and self-aligning. The ball pivot inside the stamped steel rocker arm allows the tip of the rocker arm to follow the top of the valve as the valve is pushed open. This creates some back and forth scrubbing friction between the tip of the rocker arm and the top of the valve. And the higher the valve lift and the stiffer the springs, the greater the friction. Over time, this can cause side wear in the valve guides, tip wear on the end of the valve stems, and worn rocker arms.

Aftermarket performance rocker arms, whether they are stamped steel, stainless steel, or diecast, extruded or machined aluminum, usually have a roller tip to reduce friction between the rocker arm and valve. The roller, in theory, rolls back and forth on the top of the valve stem to reduce friction, wear and side forces exerted against the valve. Most stud-mounted aluminum rocker arms also have a needle bearing fulcrum to further reduce friction at the pivot point, and a hardened steel insert in the short end of the arm to accommodate the pushrod. Power gains of 15 to 30 horsepower are often claimed for aftermarket rocker arms even with stock ratios because of reduced friction. Aftermarket performance rocker arms are also stronger than stock stamped steel rocker arms, and provide improved reliability and longevity. But stud-mounted rockers have certain limitations.

One is that they often require pushrod guide plates to help keep everything in proper alignment, especially at high rpms and spring loads. Another limitation is that they can't handle valvetrain misalignment very well. If the rocker arm twists, it may bend the pushrod and/or allow the tip of the rocker arm to walk off the side the valve tip. If that happens, the rocker may push down on the retainer instead of the valve, causing the locks to pop out and the valve to disappear down the guide, destroying the engine.

The hot setup today is shaft-mounted rocker arms. Shaft mounted rockers would seem to be a throwback to the days before the first stud-mounted stamped steel rocker arms appeared on small block Chevy V8s in 1955. One of the features that made the SB Chevy such a performer was its lightweight, high revving valvetrain. But keep in mind, that was a time when maximum engine speeds were in the 6,500 to 7,000 rpm range, not 8,500 to 9,000 rpm or higher, and most engines were running single springs, not double or even triple springs.

Shaft mounted rockers have a number of advantages. One is better alignment. The shaft is rigid so the rockers are held in perfect alignment. This eliminates the need for separate pushrod guide plates while also limiting valve train deflection. At high rpm, pushrods and rocker arm studs can flex quite a bit, and the more they deflect the more it hurts valve lift, duration and valve control. This costs horsepower and can be seen on a dyno. So the more rigid the valvetrain, the less the valve flutter at high rpm. Shaft mounted rocker arms also provide extra strength and support, eliminating the need for a separate stud girdle. Aluminum stud girdles are often necessary to reinforce the valvetrain when a high lift cam (or rockers) and stiff springs are used. The girdle clamps around the studs and ties them together to reduce stud flex and the risk of breakage. But the girdle also makes it harder to adjust the valves. Shaft mounted rocker arms don't have that issue because the adjusters are on the arms, not the studs, and are easily accessible.

Mounting the rocker arms on a rigid shaft also eliminates the "jack hammer" effect that occurs with stud-mounted rockers. Every time the valve opens and closes, the change in valve lash that occurs with a solid lifter cam causes a stud-mounted rocker arm to slide up and down on its stud. This hammering effect can pull a pressed-in stud out of the cylinder head, and may cause fatigue failure in a screw-in stud or the rocker arm.

Another advantage of shaft-mounted rockers is better geometry. By lowering the pivot point of the rockers slightly with respect to the valves and pushrods, the arc that the tip of the arm follows is moved further down the curve. This reduces the back and forth scrubbing on the top of the valve, which reduces friction even more. One supplier of shaft-mounted rockers says this change alone reduces the torque it takes to turn a SB Chevy over by 80 ft. lbs, and is good for 15 to 20 horsepower.

Lubrication can also be an advantage with shaft-mounted rockers. Some have internal oil passages that route pressurized oil directly to the rocker arms and/or valve springs instead of relying on splash lubrication from oil squirting up through the pushrods. Shaft mounted rockers are available from a number of aftermarket suppliers, and fit not only stock SB Chevy and Ford heads but also most of the popular aftermarket heads made by Brodix, World, Edelbrock and others. The shaft-mounted rockers typically sell in the $700 to $900 range and are an excellent upgrade for any performance engine.

Another supplier of aftermarket rocker arms has taken a similar approach by redesigning some of their stud-mounted rocker arms for the LS1 Chevy. The rocker arms require milling the stud pads on the cylinder heads .170" to accommodate the lowered rockers, but the net result is better geometry, less side wear on the valves and faster initial opening that produces more horsepower.

What you may not know is that the actual ratio at which a rocker arm opens a valve is not constant, but varies as the valve opens and closes depending on the arc the arm travels and the position of the rocker pivot point with respect to the top of the valve and the pushrod. The stock LS1 rockers are mounted rather high and initially open the valve at a rate equivalent to about 1.54 to 1 before eventually reaching 1.7:1. The quick lifting aftermarket rocker arms, by comparison, lift the valve off the seat at a ratio that is closer to 1.8 to 1 and then goes to 1.7 to 1 at .200" valve lift. This has the same effect as increasing valve duration about six degrees, and produces 15 to 18 more horsepower.

As the ratio of the rocker arms goes up, the net lift of the valves increase and the valve springs are compressed much closer together. Clearances must be checked to avoid coil bind and contact between the bottom of the valve retainer and top of the valve guide. Springs should have a safety margin of .060" of remaining travel at maximum valve lift to avoid coil bind. The minimum clearance between the retainer and valve guide at maximum valve lift should also be .060". If the minimum clearances are not maintained and the valve spring or retainer bottoms out, the valvetrain will usually bend or break a pushrod. Clearance between the rocker arm and spring retainer must also be checked at maximum lift to make sure they don't touch. The stock rockers on a SB Chevy V8 can handle about .470" of valve lift. More lift requires switching to "long slot" rockers or aftermarket rockers with extra clearance.

High lift aftermarket rocker arms or a high lift cam may require using different springs that allow increased spring travel. Some springs cannot handle a maximum valve lift of more than .550". For higher lifts, different springs are required. Follow the spring supplier's recommendations when matching valve springs to maximum valve lift. Another way to avoid spring bind is to raise the installed height of the valve or to lower the spring seat. But both of these will reduce spring tension, which is not the way to go with a high revving engine.

For small block street performance engines with a flat tappet cam and no more than .450" of lift, single springs with 80 to 90 lbs. of seat pressure with the valves closed are usually adequate. For street/strip performance engines, springs with 100 to 120 lbs. of seat pressure are usually recommended. For street hydraulic roller cams, seat pressure should typically be 105 to 140 lbs., and should not exceed a maximum of 150 lbs. with a mechanical roller cam.

Double or even triple springs are usually required to achieve higher spring pressures. Seat pressures for double springs typically range from 130 to 150 lbs. or higher, and 300 or more lbs. for triple springs. Most NASCAR teams run dual springs with seat pressures of 190 to 200 lbs. and open pressures of 500 to 600 lbs. at .750" lift. Pro Stock drag racers, by comparison, typically run triple springs with seat pressures of 375 to 475 lbs. with the valves closed, and up to 1,000 lbs. open!

Increasing spring pressure increases the rpm and horsepower potential of the engine. Every additional 100 rpm may be worth an extra 20 or more horsepower on a highly modified performance motor. The current limit for steel valve springs is about 83 to 85 cycles per second, or about 10,000 rpm. NASCAR teams run a 200 to 400 mile race at 8,500 to 9,000 rpm. But drag racers only run a quarter of a mile.

High pressure valve springs can deliver the rpms, but there's a price to be paid because the springs don't last. Running at such high rpm wears out the springs. Consequently, the springs have to be replaced fairly often (every race with NASCAR engines, and after so many runs with drag racers).

Higher spring pressures also puts more load on the rocker arms, pushrods, lifters and cam lobes, which increases the risk of something breaking.

According to one major camshaft supplier, standard camshafts can usually handle open valve spring pressures of up to 550 lbs. But for higher spring pressures, a carburized 8620 or 9310 steel camshaft is required.

Installing double springs may require the following modifications:

Flycutting the spring seats in the heads to accept the springs.
Changing the spring retainers to ones that are designed for double or triple springs.
Changing the valve seals and/or machining the guides for extra clearance.
Replacing pressed-in rocker arm studs with screw-in studs and a stud girdle, or installing shaft-mounted rocker arms.
Replacing the stock pushrods with stronger and stiffer 4130 chrome moly pushrods (to prevent pushrod flexing and breakage).
If the springs provide more than 350 lbs. of pressure when the valves are open, the stock stamped steel rockers will have to be replaced with stronger aftermarket steel or aluminum rockers.

Beehive springs that taper towards the top are a hot commodity in the aftermarket, but date back to the earliest days of the automobile. Like shaft-mounted rockers, though, they are finding new applications in todays high performance engines. Chevy LS1/LS7 series engines use a factory beehive spring, as do Ford modular 4.6L V8s. Similar spring designs have been developed for SB Chevy and Ford engines by aftermarket suppliers. Unlike a conventional valve spring that has a constant diameter, a beehive spring tapers in toward the top sort of like a real beehive (thus the name). A smaller top means a smaller and lighter valve spring retainer can be used to reduce weight. Also, the change in the diameter of the spring as it tapers toward the top creates a progressive spring rate that helps the spring resist harmonics that occur in conventional constant rate springs. The bottom line is that beehive springs perform better than conventional single springs on many (but not all) engine applications.

One spring supplier said their beehive springs can increase the rpm potential of an engine 100 to 1,200 rpm depending on the cam, valvetrain and other engine modifications. The maximum amount of valve lift a beehive spring can handle is about .650", so if the engine needs more lift it will require dual or triple springs.

Beehive springs have been popular on the street, but some racers are cautious about using them because there's no safety margin if a spring breaks. With a double or triple spring, the engine won't eat a valve if a spring breaks. The extra springs serve as a backup to pull the valve shut.

Heat is the main enemy of the springs, with dual and triple springs typically generating more heat than single springs because they rub against each other. Managing heat, therefore, is critical for spring longevity.

The durability of a spring depends on the quality and purity of the alloy that is used to manufacture the spring, the heat treatment the spring receives, and any additional surface treatments the spring is given. Some springs are nitrited while others are coated with proprietary chemicals that help the spring run cooler. Another trick that can extend spring life is to have the springs cryogenically treated. Freezing the springs to 300 degrees below zero can increase spring life up to five-fold, according to those who do it.

There are a couple of things to watch when installing valve springs. One is height. This ensures the springs have the required pressure to keep the valves shut. Height is checked by measuring the distance between the spring seat in the head and the retainer on the valve stem. Most performance valve springs are closely matched, but if adjustments are needed it can be done by shimming the valves to equalize pressures. The thicker the shim, the more it increases spring pressure. Don't overshim, though, because doing so may lead to coil bind with a high lift cam or rocker arms.

Shims are made of hardened steel, come in various thicknesses and are usually serrated on one side to prevent rotation (the serrated side faces the head). Some shims are also designed to help insulate the springs from heat generated by the cylinder head. Springs should also be lubricated when they are installed in a new engine, especially double and triple springs, to reduce friction. Soaking the springs in oil or coating them with assembly lube should provide adequate protection during the critical first start-up.

Reducing weight on the valve side of the rocker arm has more of an impact than reducing weight on the pushrod side because of the leverage effect. Lightweight valve retainers made of titanium have long been the preferred upgrade here. But in the past year, the price of titanium has skyrocketed. Most of the world's titanium supply comes from Russia and is being consumed by China. Some aftermarket suppliers have responded to the changing market conditions by introducing new lightweight steel retainers.

For street applications, steel retainers with stock 7 degree locks are usually recommended. But for racing or high rpm roller cams, titanium retainers with 7 or 10 degree locks can reduce weight. Some locks have an extra step inside that reinforces the bottom of the retainer and reduces the risk of the valve pulling through at high rpm. When the valve locks are installed around the valve stem, their edges must not touch each other. They should clamp against the valve stem and hold it securely. Keep in mind that the design of the retainer affects the installed valve height and spring tension.
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Staff member
Ive seen a few guys take injector fuel rail like something similar too these pictures below and have it drilled thru the valve cover ,you drill and weld the EFI fuel rail to the aluminum valve covers and tap thru to the under side of the spray bar mounted on and welded to the outer surface of the valve cover over each rocker after taping the oil spray holes with removable holley carburetor jets so they could easily regulate the oil flow rates by swapping jet sizes and feed the EFI fuel rail with pressurized oil .
adding an oil cooler and a windage screen and 7-9 quart baffled oil pan to the car also has major benefits on endurance applications
don,t forget that oil flow rates, and reducing the transmission fluid temp in the lower radiator on cars equipped with an automatic transmission, have a big effect on engine cooling so adding a trans or oil cooler helps engine durability
posted these diagrams that will be helpful













these pictures are NOT of an oil spray fabrication, but they would look vaguely similar to what you might want to do to plumb a separate oil and spray bar system on a valve cover, thats fed from a hydraulic hose attached to the engine high pressure oil passages or a separate belt driven external oil pump




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Thanks ever so much for the extensive reply. Never thought about using raw fuel rail as a spray bar for the valve springs. Damn good idea also to use Holley Carb jets in the spray bar to regulate oil flow. Would like it even better if it were a spray pattern vertical in nature to better cover the valve springs.

I was lucky to run into your discussion of this subject as it promotes reliability of the valve train and of the engine proper. Keep up the good work. Thanks again for the reply.


Staff member

B/B Chevy Valve Spring Oiling System

Valve cover rails are a Keith Eickert exclusive product that has been designed to solve the problem of excessive valve train failure. Valve spring fatigue and failure cause by long duration engine operation at higher engine rpm’s. Valve spring oilers are an industry standard in many forms of professional motorsports. Now this system can easily be installed on nearly all big block chevrolet application to dramatically extend valve train life. The oiling rail is 3/8" thick and incorporates 8 precision oil metering spray jets that distribute additional oil towards the valve spring. Simple 1/16" NPT single female oil inlets per rail provide ease of plumbing. Sold in pairs.

TECH: On engines with a higher average rpm and power band the stock oil flow thru the valve train can be marginal at best. This is a very common cause of premature wear and escalating oil temps. Most conditions on endurance applications such as performance boats or off shore race boats plumbing a separate pressurized spray bar to cool valve springs and rockers that feeds from either a passage in the block or a separate oil supply has proven to be extremely key to long term durability, because the rapid cycling torsional stress on valve springs can easily cause them to heat to over 700F if not bathed in a constant flow of oil that absorbs and carry's away the heat that builds up rapidly, many shaft rocker systems have strategically located oil shaft holes that direct flowing oil to the valve springs and rockers. *most people don,t understand that almost 1/2 of an engines total heat comes from the valve train and bearing friction.


Small Block Chevy Valve Spring Oiling System

Valve cover rails are a Keith Eickert exclusive product that has been designed to solve the problem of excessive valve train failure. Valve spring fatigue and failure cause by long duration engine operation at higher engine rpm’s. Valve spring oilers are an industry standard in many forms of professional motorsports. Now this system can easily be installed on nearly all small block chevrolet application to dramatically extend valve train life. Simple 1/16" NPT single female oil inlets per rail provide ease of plumbing. Sold in pairs.

TECH: On engines with a higher average rpm and power band the stock oil flow thru the valve train can be marginal at best. This is a very common cause of premature wear and escalating oil temps. Most conditions on endurance applications such as performance boats or off shore race boats plumbing a separate pressurized spray bar to cool valve springs and rockers that feeds from either a passage in the block or a separate oil supply has proven to be extremely key to long term durability, because the rapid cycling torsional stress on valve springs can easily cause them to heat to over 700F if not bathed in a constant flow of oil that absorbs and carry's away the heat that builds up rapidly, many shaft rocker systems have strategically located oil shaft holes that direct flowing oil to the valve springs and rockers. Most people don't understand that almost 1/2 of an engines total heat comes from the valve train and bearing friction. ... ystem.aspx


BTW you can weld fuel rail to true aluminum fabricated valve covers similar to these above, but many
"CAST ALUMINUM" valve covers are ZINC or POT METAL and can,t be welded on like these below, so you would need to mechanically lock the rail with screws and epoxy, if you chose to use those


viewtopic.php?f=44&t=1599 ... ?gfid=p285

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The Grumpy Grease Monkey mechanical engineer.
Staff member
if your going to use a valve train cooling oil flow to cool the valve springs ,you may want to consider other options like a transmission fluid cooler and an oil accumulator
roller TIP rockers like this are basically a total waste of time, money and effort, the tips of the valves on the rocker provide MINIMAL friction its the fulcrum the rocker pivots on at the rocker stud, that needs a roller bearing and thats where you gain most of the power gain, in reduced friction, the increase in valve lift is a small help but not nearly what the reduced friction in the valve train provides
its not that difficult to remove the oil pan, replace the gasket with a new one piece synthetic one and cure that leak,
most guys can do that in a single afternoon with the car up on 4 12 ton jack stands rather easily.
be aware that the crank counter weights rotated to the correct location makes removing the oil pan a bit easier.
it might be a great opportunity to swap to a higher capacity baffled oil pan.

you should NEVER shim an oil pumps pressure relief spring as it may prevent the piston it holds from moving down its bore far enough to allow it to open the bay-pass passage, that allows the pressure on the high pressure side of the oil pump from bleeding off back into the intakes side of the oil pump



Many pressure relief springs have one end larger than the other end,the spring always mounts with the larger end facing away from the bypass piston, if installed reversed the piston can,t move far enough to completely open the bypass circuit passage and pressures skyrocket, under some conditions

in my opinion , and experience and from lots of G.M. engine, race testing.
theres no need for oil pressure to exceed about 65 psi,
it takes power to spin the oil pump against that extra resistance, it induces extra wear on the distributor and cam gears,
and it does nothing to reduce bearing wear or increase cooling on the bearing surfaces,if your engine shows more than about 70 psi, you should open some bearing clearances marginally
(maybe an extra half thousandth on the mains) to increase oil flow volume reaching the main bearings, and use a lower resistance oil pump bye-pass spring.
extra oil flow volume cooling the bearings and valve train will do more for durability than oil pressure exceeding 65-70 psi

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.
7" deep
6.5" deep

7" deep

theres lots of 8" and 8.25" deep corvette oil pans but they don,t last too long with speed bumps and raised manhole cover rims

12. Failure to clearance lifters in their bores.

Grooved lifter bores
Lifter clearance should be 0.0012" to 0.002", with 0.0015" (one and one half thousandths) considered close to ideal. Too loose can be as bad as too tight. One way to provide a flat tappet cam and lifters with additional lubrication is to groove the lifter bores. One tool for doing this operation is the Comp Cams p/n 5003 lifter bore grooving tool sold by Summit. Solid lifter flat tappet lifters are available with a small machined hole in the lifter foot that feeds pressurized oil to the interface between the cam and lifter. But having that hole is no guarantee (see photo below)...





IT helps to know exactly what year and casting number your engine block is as early production big block engines used a different rear cam bearing and cam, a potential rear cam bearing oil flow issue is found on the 1965- too a few very early 1967 engines ,if you install the older design BBC cam with a grooved rear main in EITHER config with EITHER rear bearing your covered, and since thats just not expensive and any decent machine shop can modify any cam like that cheaply is the smart route to take if your in doubt. obviously having the machine shop groove the rear cam journal under the cam bearing in the block like the later BBC engines would be ideal.
Id also suggest you install a long higher capacity oil filter if you have the clearance to do so, as both the extra oil capacity and the fact that the larger oil filter with its greater surface area constantly exposed to outside air flow, (especially if you have an oil filter finned cooler) can in many cases reduce oil temps 5 degrees or more



I don,t know where they sell these, finned aluminum filter covers now ,a few years back these were $20 each and significantly longer that this picture shows,
in fact they were the length of the long oil filter ,and believe it or not the combo of the longer oil filter and finned cover dropped my oil temps an additional 5 deg F , EASY TO PROVE by simply removing and replacing the slip on finned cover several times after keeping detailed records while cruising the interstate at a steady 70 mph (not a big difference but for $20 well worth it!
yes you can get a bit more creative and build or buy something with significantly more surface area for increased cooling capacity if you might feel inclined

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

this lower designs what Ive used for decades:like:




ok, basics, the oil enters the lifter from block oil passages under pump pressure while the lifters on the cams base circle,
with near zero valve spring pressure on the lifter seat,
the hydraulic oil pressure lifts the push rod seat taking up the valve train clearance.
as the cam rotates the lifter moving up off the cams base circle causes the lifters push rod seat to momentarily move down compressing the trapped oil volume , as the push rod seat is compressed,down into the lifter body,
forcing oil trapped in the lifter up through the push rod,, the trapped , and now further pressurized oil is there for two different requirements,
first it lubes and cools the valve train, as it exits the rocker/push rods and flows over the rocker and valve springs,and second it quiets the valve train by removing the clearance, with a cushioned floating push rod seat,
that clearance is required for the valve train to function.
but the clearance results in a ticking sound like solid lifters produce,
adding a hydraulic supported push rod seat quiets the valve train,
and without the hydraulically supported push rod seat,the valve train requires periodic clearance adjustments ,
the hydraulic supported push rod seat is fully compressed, by the cam lobe forcing the lifter up against the push rod and the valve springs resistance,
by the time the cam lobe reaches peak lift ,
but at lower rpms all the oil is forced up and out of the lifter well before the lifter is near full lift on the cam lobe,
now it is possible that at extremely high rpms the lifter bleed down rate does not have sufficient time to vent all the trapped oil,
this is commonly thought to result in valve float,
but thats not likely, the inertial loads on the lifter and valve train not being completely controlled by the valve spring resistance,
and ability to seat the valve firmly and keep it seated as the lift returns to the cam lobe base circle,
and the lifter loosing firm contact with the cam lobe and or bouncing,
as it re-seats is far more commonly the fault.






most of the GIVE or clearance or movement in a hydraulic lifter push rod seat is the result of pressurized oil flowing into and lifting the push rod seat, without the pressurized oil entering the lifter body,from the sides of the lifter body from the oil passages in the block, manually forcing the push rod seat down into the lifter body is basically a one shot deal that generally only going to compress in a minimal .060 -.08 once until oil pressure forces the seat back up.
you'll need to dissipate the heat that oil flow collects as it runs over the surface of those hot valve springs and a combination of a higher capacity baffled oil pan ,

and an auxiliary oil cooler to make transferring the absorbed heat load the oil carries away from the upper engine is almost 100% mandatory if your expecting the oil to cool the valve train for very long.
Id point out that you'll almost certainly want to use an oil cooler that's as large as you have room to effectively use and having a powered fan to increase air flow and heat transfer efficiency will help, bu remember the line size between the engine cooler and back to the engine will generally slightly restrict flow so, I,d advise at least a AN#8 or 1/2" internal cross sectional, size oil or hydraulic lines designed to handle 300F temps and pressure levels with a significant safety margin above what the engine produces, and having large remote mounted oil filter(s) won,t hurt either.
Yes they make dual transmission fluid and oil coolers so you might want to consider that option if you have an automatic transmission and Id sure suggest a fluid temp gauge that accurately measures transmission fluid and a separated gauge for oil temperatures.
IM currently using this transmission fluid cooler on my 1985 corvette but have used others in the past, and a dual cooler like this certainly has some advantages , if you need both oil and transmission fluid cooling.
prm-13311 (1).jpg

if your concerned,

something like this makes a noticeable improvement

when you say 215F do you mean the normal rise in temp after shut-down?
oil temps SHOULD reach 215F occasionally during engine operation,
to insure all moisture is boiled off
but keep in mind , oil in the sump is going to be significantly cooler than,
oil flowing over,
rocker pivot balls,
cam lobes,
valve springs lifters,
piston skirts and rings
oil, flowing over the moving and sliding components absorbs a great deal of heat,
that hot oil flowing over the engine block and heads has,
its heat load rapidly absorbed and transferred too coolant,
flowing through the major components, that coolant absorbs heat from the hot oil,
and transfers it to the outside air flow ,
and air flowing over the oil pan and valve covers is easily 40F-100F cooler than the oil,
this is how much of the initial heat is transferred,now oil in your oil pan will be by design cooler than it is in other locations,
and oil flow cycles endlessly so while your engine may only hold 4-8 quarts, theres 2-7 gallons a minute passing through the oil pump,
that flow changes, depending on clearances and rpms of course, so the longer any engine runs the more passes,
the individual oil molecules have of being repeatedly heated and cooled, thus moisture boiled out, but moisture will not be totally removed unless,
oil reaches about 215F repeatedly,

this almost mandates a 190F-205F oil pan oil temp.





as a general rule you select .001 bearing clearance for every inch of bearing journal diameter,

Rod bearings 0.002 - 0.025" , side clearance 0.010 - 0.020"

Main bearings 0.002 - 0.003" for most engines ( 0.020-0.025 bearing clearance on small blocks, .025-.027 bearing clearance is about ideal, on big blocks ), 0.005 - 0.007 crankshaft end play

Adding a high quality transmission and oil cooler with low flow restriction 1/2" MINIMUM ID lines can markedly increase engine longevity and durability









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




most hydraulic supply shops will fabricate lines to your exact length and use the correct fittings and hose types to allow over 1000psi and 300F fluid temps, if you do a bit of reserch youll find a couple hydraulic supply shops locally

yes there are oil to engine coolant heat ex-changers, that will act to maintain the oil temp at or near the always slightly lower coolant temps in an engine
I find it rather amazing that many guys (even a few corvette owners) don,t realize that the oil cooler between the block and oil filter does remove a noticeable amount of heat from the engine oil, or that in some cases that they even have an oil cooler factory installed. ITS OIL FLOW that absorbs and initially transfers heat away from the bearings and valve train not coolant.
my 1985 corvette came with a factory oil cooler, that runs engine coolant through separate but contacting internal passages, this warms the oil faster getting it flowing but tends to reduce the heat engine oil can reach as it absorbs oil heat effectively transferring it too the engine coolant on the car, where its transferred too air flow through the radiator







this is one reason why combining both the engine oil cooler and transmission fluid cooler in a single dual unit is not always ideal,in every car, as an example on my corvette I found that I did need an oil cooler but did need a trans cooler , because once I installed a custom 10 qt oil pan on my 383 the oil temp stayed in the desired range due to the pans much larger surface area and the and much larger capacity, but the transmission fluid due to the 3200 stall speed converter did need to be cooled



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 ... _15721.pdf


If your going to run an effective oil cooler with a fan youll generally want a thermostat controling oil temps to be sure the oils neither too hot or too cold, youll generally want the oil to rather rapidly heat to a 200F-21fF range during normal operation,to insure its hot enough to boil off moisture , and reduce sludge but run through the cooler to prevent it getting over about 220F where the temp tends to degrade lubrication effecincy




a few links may help here

If you think about it a bit all a knock sensor does is retard ignition advance timing,
to the point the engine no longer detonates due to too much heat in the combustion chamber for the advance curve and fuel octane.
obviously if you have experience tuning a certain engine and your fuel octane is fairly consistent, you can change the ignition advance curve to match ,
the engines documented and tested power potential.
that does not mean a knock sensor is not useful , simply because fuel quality and engine cooling efficiency varies with outside air temps.
and your cars radiator and oil and trans fluid cooling efficiency, but a good tuner can avoid getting into detonation range, with a known engine combo, a high percentage of the time.
obviously boosting your fuels octane, and fuel to air ratio to cool the combustion helps so thats the first part of the equation,
retarding the cam timing reduces effective compression,
retarding the ignition curve will reduce cylinder heat and effective pressure,
all factors should reduce detonation,
easily 60% of the most common engine detonation is not in the normal adult humans hearing range
detonation damage is cumulative!
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The Grumpy Grease Monkey mechanical engineer.
Staff member

some people find that installing valve cover spacers between the valve cover and the oil spray bars on BBC engines with roller rockers provides a more consistent oil flow rate to roller rockers and the added height helps maintain the oil flow directly too the roller rockers AND provides a bit more clearance for the valve train, if your using tall poly locks and valve train stud stabilizer kits (rocker stud clamps)ID ALSO POINT OUT THAT A ROCKER STUD GIRDLE ADDS A GOOD DEAL MORE STABILITY TO THE VALVE TRAIN And valve springs and roller rockers last much longer if the added oil spray bar is used to provide added cooling and constant lubrication, along with the rocker stud girdle




TECH: On engines with a higher average rpm and power band the stock oil flow thru the valve train can be marginal at best. This is a very common cause of premature wear and escalating oil temps. Most conditions on endurance applications such as performance boats or off shore race boats plumbing a separate pressurized spray bar to cool valve springs and rockers that feeds from either a passage in the block or a separate oil supply has proven to be extremely key to long term durability, because the rapid cycling torsional stress on valve springs can easily cause them to heat to over 700F if not bathed in a constant flow of oil that absorbs and carry's away the heat that builds up rapidly, many shaft rocker systems have strategically located oil shaft holes that direct flowing oil to the valve springs and rockers. Most people don't understand that almost 1/2 of an engines total heat comes from the valve train and bearing friction. ... ystem.aspx

related info

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