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Keith Black oil pump pressure adjustment?

Posted By: SoCalRacer

Keith Black oil pump pressure adjustment? - 08/01/17 06:35 AM

I have a KB Hemi/BB aluminum body oil pump with -12AN external lines that looks like ones I've seen on fueler engines. I think it is putting out too much pressure (90+ psi). Does anybody have an instruction sheet for one of these that shows how to adjust the pump pressure?

Thanks
Posted By: AndyF

Re: Keith Black oil pump pressure adjustment? - 08/01/17 06:47 AM

Well what do you expect? That oil pump is designed for a funny car engine so it pumps a lot of oil. When you try to push a lot of oil into a tiny hole you get a lot of pressure. There is not any way to reduce the oil pressure since you are dealing with a lot of volume. If you back off the pressure relief valve setting then you will still pump all of the oil but now you'll recycle it thru the pump. When you do that you add heat to the oil.

If you aren't running a funny car engine with huge bearing clearances then don't use a funny car oil pump. If you have normal bearing clearance then the stock HV pump should work fine. These days I run a standard oil pump (non-HV) on my engines and they hold 80 psi at 7000 rpm with 5w30 oil.
Posted By: dthemi

Re: Keith Black oil pump pressure adjustment? - 08/01/17 01:33 PM

Milodon makes, or you can make yourself, an adjustable spring cap that fits the KB pumps. Basically just a cap with an adjuster screw to add, or relive pressure on the spring.

https://goo.gl/images/3GEYrQ
Posted By: AndyF

Re: Keith Black oil pump pressure adjustment? - 08/01/17 04:21 PM

The really big pumps will overwhelm the relief valve and the pressure will still go up. I ran into this problem years ago when I first tried a huge oil pump on a basically stock type engine. The volume of oil is so high that it can't all fit thru the relief valve without high pressure so as RPM goes up the pressure just keeps climbing.
Posted By: MR_P_BODY

Re: Keith Black oil pump pressure adjustment? - 08/01/17 05:16 PM

First what weight oil in it
wave
Posted By: Efidart

Re: Keith Black oil pump pressure adjustment? - 08/01/17 05:45 PM

The Milodon 21 GPM pump I'm running is netting me around 110 PSI up top, took a bit of shimming and finding the stiffest bypass spring to get it up there.
If you do want to lower it the Milodon adjustable one works if it doesn't interfere with your motor mounts.
Posted By: SoCalRacer

Re: Keith Black oil pump pressure adjustment? - 08/02/17 05:31 AM

Straight 30 weight Brad Penn is what the previous owner put in it. I have seen the Milodon adjuster and know how to play the relief spring game, I just didn't know if the KB had a pressure adjustment method built-in. From some replies it sounds like 90 psi isn't all that bad? Engine is an iron RB with Edelbrock heads....nothing trick, car only runs 9.60's

It's only the second time out since I got it, but I'll pay closer attention to it at the track this weekend; see what it does when hot, at higher rpm, etc.
Posted By: Cab_Burge

Re: Keith Black oil pump pressure adjustment? - 08/02/17 09:12 AM

I like and use 5W20WT straight Valvoline oil in my race motors with solid roller cams on E85 fuel. I do trim the bypass springs on the Mellings and Speed Pro high volume oil pumps I use to get 10 lbs. per 1000 RPM with hot oil, IE 70 lbs. at 7000 RPM with 160 F + oil temps up
I run loose bearing clearances(.004+ on the mains and .003+ on the rods ) and oil the rocker shafts full time also shruggy
Posted By: dthemi

Re: Keith Black oil pump pressure adjustment? - 08/02/17 03:24 PM

When you see pro stockers turn 10,000 on 15-20 pounds oil pressure it makes ya wonder lol.

Like Andy said, they'll still over run the bypass at higher revs, but they won't idle, or hit 100+ as soon as you blip the throttle with a softer, or adjustable spring. I like the big pumps for bracket stuff when the motor is on the line at 200 degrees from hot lapping. You'll still have pressure even if the idle is only 20 pounds.

Sure too much pressure costs a few ponies, and weening them off oil is good for power. I just haven't seen 100 pounds pressure hurt anything other than a cheap oil filter. I have seen too little volume destroy stuff.

I did a high reving small motor that i tried to cut the oil down as much as possible without losing pressure. factory steel crank in a de stroked 400, 9000rpm. The standard pump held 55 psi but ate bearings (3 times). Switched to a HV at 55 and no more trouble. Doesn't make sense, but that's how it went.
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