Yeah, I searched. Mostly questions about stock electric guages etc.

I want opinions on the best oil pressure to run on a streetport that may see a supercharger some day (unlikely right now, but I don't want to have to drop the oil pan at some point if I can sort it out right now during the build). Max RPM will be less than 8400 with stock apex seals. My rear oil pressure regulator (ROPR) is the old adjustable type. I don't want to cause unnecessary wear to the oil pump chain. The oil pump itself is the 17.5mm (high volume) type which fits '85 and older engines.

85psi maybe?

For 85psi, does it require a 1/8" stack of washers? More? Less?

Should I leave the front regulator alone?

Thank you.

 

My understanding is the front is left alone under 85 psi. The 1/8" stack of washers sounds about right for the rear. Not sure where I read the thread on this, maybe over at Nopistons in the engine builg/porting section?

 

The front is left alone under 85 psi? Mr. Atkins recommends that you shim the front the same amount as the rear when using one of their Camden superchargers. They also recommend .200" worth of shims. That's kind of a lot in my opinion. But what do I know?

The engine currently has .160" shims front and rear. The oil pump chain needs replacing. I don't want to wear the second chain out as quickly. Grumble grumble.

I suck at English measurements, so you'll have to bear with me here. Ok, according to my digital caliper, 1/8" is .138". Fair enough. That's like only two washers if I can find some at 1/16" thick in my pile.

One more facet. My friend has an S5 T2 in his REPU with a stock ROPR and it sits happily at 60 something PSI with a supercharger. Those 2nd gen engines have a larger oil pump than our 1st gen "high volume" pumps. It works great; no need for such high pressure in that engine. Less chain wear too.

So here I have three conflicting possibilities. On the one hand, I could go with 85 PSI and be good up to the engine's maximum RPM, not put too much wear on the pump chain, and it'll probably be fine with a supercharger's bearings bleeding off some of the pressure and volume. It's not like it's a huge amount.

On the other hand, I could follow The Atkins' advice and risk premature chain wear at the expense of some power, all to keep from having to drop the pan once the supercharger arrives (if I actually ever get one).

Third, since I can't use a 2nd gen's larger oil pump, maybe I could leave both regs at .160" and take my chances at 95 PSI or whatever the end result will be.

Any recommendations? I'm sorta leaning toward 85 PSI at the moment.

 

when a friend of mine rebuilt my motor he modified the oil pressure to sit at aroun 65-70 psi at idle and i dont know what id is at WOT...when i took it to WOT the needle was pegged out(over 110psi, all oil lines to oil cooler were changed to hydralic lines that handle 25k psi, and the oil injection lines were the same just slightly larger than stock and can hold up to 300psi i think)...he told me he used two shims for the oil pressure unit...but that was after the rebuild was started and ran for a good few hours put about 1500 miles and then the injectors stayed open after i let him do a tune up with timing and afew odds and ends, then we tried to start it but the injectors stay open dumpin loads of fuel and now im wait for him to help me out afterr he comes back from vacation so we can try some injectors that he has layin around....

 

Jeff,
i would definitely keep it at 85 PSI now ... and consider a possible increase when if OR when the supercharger materializes.

 

Thanks guys.

Hmm, since I tend to be lazy, I wouldn't want to risk a leaky oil pan and all the extra work and time involved to clean everything (lol), so maybe I should set it once right now and forget it. I think I'll aim for 85 PSI on the ROPR and add the same thickness in washers to the front.

If I don't get too many complaints, I'll go ahead and do it and let you guys know if and when I install this engine into something. The goal is to put it into a 1st gen. It's a street ported 4 port 13B .

My REPU has 90 PSI at high RPM when warm, and 100+ at mid RPM when cold. A bit much in my opinion. Warm idle is adequate. It only sees up to about 7k RPM since the carb maxes out up there. Yeah, I'll aim a little lower with this next engine.

 

I just reviewed most of my thread from early last year detailing this engine and it seems I may have been on the right track concerning oil pressure. I added one washer to make up for the used springs' possible sagging with age, and then two more for raising oil pressure.

I fired this engine up and it overheated within 15 minutes due to a cheap thermostat that did not open all the way. During its brief life, I can recall the guage not going past 90 PSI. This is with three washers in each pressure reg.

The engine is now ready to be torn down. I'd like to see what condition the orange coolant seals are in. If they're not burned, the rotor housings should be ok. If they're burned, the rotor housings are probably crushed. I'm pretty sure I shut the engine down in time.

 

I always shim the front cover.

 

he flattened the stock ROPR too much.

 

So far it's +3 points for 85 PSI and +2 for shimming the front reg. Cool!