Finished my engine up, last night. Has a KB Cast Pump and dual swinging pickup. Verified I have the lines to/from the filter correct. When I prime the engine with a 1/2" drill, its shooting up over 100 psi. I am a little leary to fire the engine until I can lower it some. Is the adjustment behind the big anodized cap?

fire it up then you will know what oilpreasure is

priming the oilpump will not be the same as the car is running

Ok was afraid that the drill spinning at low speed would crank it clear up past 100 that I might have way too much and didnt want to have a geyser of oil in the garage.

my motor primed is 100 psi cold

running its 80 cold

Cut the bypass spring. Then debur it of course but that is it.

You can just put in a softer spring from a passenger car. Or cut the spring. Or order up the adjustable setup.

The oil pressure with the engine running should be lower than what you see turning it by hand.

Thanks guys, I assume the spring is up in behind the plug on the right top side of the pump (looking at the block from under the car. The plug right against the block.

fire it up then you will know what oilpreasure is

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No dont do that, what ever you do.

Quote:

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priming the oilpump will not be the same as the car is running

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Correct
It will be much more than that...Figure the drill only turns 1300-1600 rpms max. if that.
It will probably burst the oil filter if you fire it.
What weight oil? Im betting bearing clearance is on the tight side. If it is, you can only help so much messing with the relief spring setup.

the rods blead off oilpreasure and rockerarms
loose clearenses too


I would start the moter off first and not cut or shim the relief spring


see where the oilpreasure is first !

The oil is straight 30 weight. Its goes well past 100 without turning the drill very hard at all.

If thats straight 30 weight with a drill, you put 20w/50 in it and give it some throttle it will peg the gauge fact. If anyone here has exploded a oil filter like me they can tell you what a horrifying experience it is.
Dont start that engine like that, foolish advice
Anything over 60-70 psi is counter productive, robs lots of power, oil is in constaint bypass, adding heat and this how people ring the intermedate shafts into.
Cut about a 1/8th inch off the spring, and retest it by priming. Priming the system will give you a ball park figure of idle oil pressure, using the same oil. You would see 10-15 more psi just by changing oil weights from 30w to 20w/50 etc.
Get the pressure down around 60 psi with the drill and the same oil you plan to run
Hope this helps

The KB cast pump has dual by-pass springs, all you need to do is remove the inter spring, and any shims (if any), this will set the pump @ about 12 GPM, The outter spring should measure 2.600 O.A.L. this will put you where you need to be for your appication.

I didnt see the last post until I already modified. I thought about trying to just remove the inner spring but didnt know if it would be enough or not. Oh well thanks anyway. I had removed the springs and taken a little over a 1/8 off of both because I was well over 100, right now I have 80 with the drill. Going to fire it up in the next day or two and see where I am running.

I run the same pump, have two actually. I just grind and dress the spring to get the pressure I am after. Must be the Neanderthal in me.

Need to have Neanderthal strength fingers to get the plug back in, especially when doing it on the car.

The correct way to lower the pressure with either of our oil pumps is to remove the inner spring first as stated by 90%. If you still have too much pressure, you can use one of our modified plunger caps #72120M for $8.20 plus shipping. This should get the pressure down to around 90-95 psi cold with 30wt oil and “standard” bearing clearances. Standard for our reference in the shop for “street engines” is .0027 to .0032. When these pumps leave here they are set to run at 120 PSI with 50wt oil, cold. You should not run this pump with Std street clearances without changing the spring and/or cap. You can also cut, grind, the spring in place of the modified cap but be sure to de-burr the ends. Also do not build up a lot of heat in the spring as this could cause a change in its function and life expectancy. We perfer that you do not cut or grind the spring. (Off the record, yes, it will work).