How much oil pressure is to much?

[gnicholson]

I wouldnt leave it like that. Too much oil pressure. Either the bypass spring is to strong, the valve isn't functioning properly" stuck in other words", or the bypass circuit cant deal with the volume of oil required to maintain the correct pressure once the engine speed goes up. I would pull the pump out and first of all make sure the pump volume isn't too great. You may need a smaller volume pump. I would disassemble the pump and check the bypass valve to make sure it easily slides in the bore. Also,check the pop off pressure. You dont need anymore than 65 lbs. If it opens around that pressure as is you have to much volume.While it was a part I would port and radius the bypass circuit to increase the oil flow.

[redliner]

Oil takes a lot longer than the coolant to heat up.

Yes! I went for a spin and got it up to 195 then shut it off and let it heat soak. The water temp said 200 - 210 and when it cooled off to 200 i fired it up and it had 40 lbs at a 1200 rpm idle and i revved it to 4000 and it went to 75 lbs. I didnt rev it any farther. I think this will suffice

[redliner]

I wouldnt leave it like that. Too much oil pressure. Either the bypass spring is to strong, the valve isn't functioning properly" stuck in other words", or the bypass circuit cant deal with the volume of oil required to maintain the correct pressure once the engine speed goes up. I would pull the pump out and first of all make sure the pump volume isn't too great. You may need a smaller volume pump. I would disassemble the pump and check the bypass valve to make sure it easily slides in the bore. Also,check the pop off pressure. You dont need anymore than 65 lbs. If it opens around that pressure as is you have to much volume.While it was a part I would port and radius the bypass circuit to increase the oil flow.

I put the red weak spring in it and have 40 lbs hot at 1200 rpm idle and 75 at 4000. It is 25% more volume and prolly to much pump for my SHP block. If the only detriment to 75 - 85 lbs of oil pressure is a slight loss of h.p. I can deal with that, or ???

[gnicholson]

Well it heats and aeriates the oil puts a strain on the pump cam timing chain and distributor. I would fix it if it were mine especially with 85 lbs plus

[Schurkey]

Consider using lighter viscosity oil.

0W30 or even 5W30 "should" all be 30 weight when warm, but I don't think it really is.

Or try an xW20 oil.

[steve316]

With the clearance you are running I would run 0-30 or 5-30. Your pressure is a little high; cost you a little HP in windage .

[Tom Walker]

The 45 P.S.I. at 1,200 idle is great, the 75 P.S.I. at 4,000 is still high. Must be a big pump to supply that much pressure with the clearances you stated. The pressure may come down, when as others have stated, the oil really gets up to temperature. I know one thing, I would choose your oil pressure issue over too little oil pressure.

[GARY C]

Oil takes a lot longer than the coolant to heat up.

Yes! I went for a spin and got it up to 195 then shut it off and let it heat soak. The water temp said 200 - 210 and when it cooled off to 200 i fired it up and it had 40 lbs at a 1200 rpm idle and i revved it to 4000 and it went to 75 lbs. I didnt rev it any farther. I think this will suffice

This is true, I found that out when I installed an oil temp gauge on my race car, the gauge started at 100 and it was well after water temp got to operating temp before the oil gauge would start moving.

With a fresh build and fresh oil I would take for a decent cruise with out getting on it and see where it settles.

My nitrous 357 had a max of 75psi on the dyno with 20/50, that was higher than I would have liked but we made 21 pulls in the 7500 to 7700 rpm range and nitrous shots from 150 to 300 and everything was good on tear down.