For you guys with brand new engines... After your car is warmed up (20 minutes +) what is your oil pressure?

Specifically for a stock oil pump with white or yellow spring. Please specify what type of oil pump/spring & oil weight that your using in your response.

Should your oil pressure drop from 60-70psi to 20-25psi after your car is warmed up on a new engine?

 

At what RPM do you see those pressures? What viscosity oil are you using? What does the person who assembled the engine think about the numbers you are quoting?

 

hot idle with white spring (stock replacement melling) is ~45,
anything off idle is ~65-70
and wot is ~80

10-40 dino

 

High volume pump (extra capacity pan), stock"ish" bearing clearances, M1 5W30

Cold idle ~50-60PSI
Hot idle ~25 PSI
Off idle ~50+ PSI
WOT ~75-80 PSI

 

Even with a high pressure spring using a new stock GM pump my oil pressure would drop to just above the 1st bar indicator so 25psi or so at idle. Start up was 70 psi .. and normal driving was around 40-45psi. This is using 10w30.
The person who built the engine didn’t think it was out of the norm but I wouldn’t entirely rely on his opinion since Im asking this because the engine he has built has spun a bearing. 3 fresh rebuilds and 3 spun bearings after 500-1200 miles each.
Im trying to get an idea of what oil pressures I can expect to see on a fresh 355 build. I wonder if there is something different about the oil distribution on the LT1 vs older 350’s. And the engine builder is doing something wrong to on the LT1 short block rebuild that would normally be right on an older 350.?

 

sounds like its time for a new engine builder

 

Before my rebuild my 145k miles original engine had 25 psi hot and 40 cold with 10-30 oil at idle. new engine with stock melling oil pump with the 3/4 inlet and whatever spring is installed by melling is. 75 psi cold and 55 hot "185 degrees" from the initial start up to 500 miles it has only lost a few psi.

 

It depends on bearing clearances, but the drop you post is quite normal. Every single engine out there is going to experience higher pressures at cold startup due to the oil viscosity. Pressure will lower as the engine heats up and oil thins out.

 

Sounds fine to me. Some of you are running too much oil pressure. But I have beaten that horse enough in the past. Fully warm, 15-20psi is fine for hot idle, just be sure that the pressure increases ~10psi/1,000rpm. If it maxes out at 60ish, that's fine. Cup cars are very happy with less oil pressure than that for 500m at over 8,500rpm.

Rich

 

I'm of the opinion I'm running too much pressure.

I have a non-HV Moroso pump and welded pickup sitting in a box waiting to go in next time the pan comes off (possibly during a kmember swap).

I don't feel like going through the trouble of it right now though, so it just is what it is