Whats "Normal" Operating Temp Oil PSI

W

WHTTRSH

Sleeper
Joined
May 1, 2011
So I just got my engine back from Dan Strezo at DLS and put it in. 3.8 Stroker motor w roller cam/valvetrain. Performed two heat cycles with Brad Penn 30W w Zinc additive for engine break in. Drained and then filled with Dans recommendation of normal Valvoline 10W30. Running a WIX 51036 filter.

Hot oil psi is good, 40-60psi under throttle. My concern is 9-10psi @ HOT IDLE. It goes up right away though once I step into the throttle. GM service manual mentions nothing of hot idle oil psi specs. They just state to check it at operating temp @ 2400RPM and look for 37psi. I have that so am I good....Just seems low @ idle? Is that ok? Does the engine still need to break in? Should I run thicker oil?

Thats my only concern otherwise engine seems to run smooth.
 
WHTTRSH said:
So I just got my engine back from Dan Strezo at DLS and put it in. 3.8 Stroker motor w roller cam/valvetrain. Performed two heat cycles with Brad Penn 30W w Zinc additive for engine break in. Drained and then filled with Dans recommendation of normal Valvoline 10W30. Running a WIX 51036 filter.

Hot oil psi is good, 40-60psi under throttle. My concern is 9-10psi @ HOT IDLE. It goes up right away though once I step into the throttle. GM service manual mentions nothing of hot idle oil psi specs. They just state to check it at operating temp @ 2400RPM and look for 37psi. I have that so am I good....Just seems low @ idle? Is that ok? Does the engine still need to break in? Should I run thicker oil?

Thats my only concern otherwise engine seems to run smooth.
Click to expand...
What is your RPM at Idle? Seems a little low.
 
If in doubt check with another mechanical gage.....seems a little low .
 
WHTTRSH said:
So I just got my engine back from Dan Strezo at DLS and put it in. 3.8 Stroker motor w roller cam/valvetrain. Performed two heat cycles with Brad Penn 30W w Zinc additive for engine break in. Drained and then filled with Dans recommendation of normal Valvoline 10W30. Running a WIX 51036 filter.

Hot oil psi is good, 40-60psi under throttle. My concern is 9-10psi @ HOT IDLE. It goes up right away though once I step into the throttle. GM service manual mentions nothing of hot idle oil psi specs. They just state to check it at operating temp @ 2400RPM and look for 37psi. I have that so am I good....Just seems low @ idle? Is that ok? Does the engine still need to break in? Should I run thicker oil?

Thats my only concern otherwise engine seems to run smooth.
Click to expand...
Also, call Dan.
 
If you have about 10-13 per 1000 rpm you should be good. So @ 5000 you need a bit over 50 psi. With oil hot.
 
WHTTRSH said:
.................... Should I run thicker oil?

Thats my only concern otherwise engine seems to run smooth.
Click to expand...

My opinion is to run Valvoline 20W-50 oil as this is an expensive performance build.

Our performance engine builds usually have 35-45 PSI oil pressure at operating temp, and as much as 90-100 PSI at start-up. The lowest I see on my race engine after a 9 sec. pass is 35 PSI and back to 50 PSI by the time I return to the pit.

I will never run any commercial spin-on oil filter and a race car, or even my street cars? They are too restrictive, and the filter media will NOT hold up the higher oil pressure.
 
Talked to a buddy w one and he says he's around 12-15 @ idle w 20W50. So that explains why I'm around 10 w 10W30. I'll run the VR1 20W50.
 
Cold start looks good but that hot idle psi seems alittle low especially for new build, in my opinion it should at least hot idle at 20. Thats at 850-900 rpms.
 
P.S. For that build i would also talk to Nick and order nice k&p oil filter, nice peice and only have to buy once. He will exsplain to you why.
 
Sounds like you may have some excessive clearance in the oil pump/timing cover somewhere. The aluminum cover and steel gears expand at different rates which contributes to the wide swing in pressures.

The cold pressure is in the ballpark but a fresh rebuild should see a minimum of 20lbs. hot in my experience. 25 to 30 and you have everything spot on.

Do you have a H/V pump? Tell us more about you bearing clearances and oiling system.

Chinese or factory T/C?

Were there any oil mods done to the cover??

If you know the bearing clearances you can rule that out if within spec and look to the oiling system.
 
Hot idle oil pressure depends on many things......crankshaft bearing and also cam bearing clearances being at the top of the list.
also is this a hydraulic lifter or solid roller lifter cam.....solid rollers bleed off more oil than hydros do and will cause lower Idle oil psi numbers.....

The condition of the front cover and oil pump gears plays into this as well.....I would talk to your engine builder and see what he thinks about your pressure..

As scary as it sounds I have seen 5# hot idle and 45# hot at WOT oil pressure work without issues.....Not how I would build an engine but it worked none the less...

Ideally you would like to see 20 psi hot idle in gear and up to 60 psi as soon as the engine speed gets up over 2000 rpm.

and as Nick eluded to your choice of oil and filter type will impact this as well.
 
Just put together my motor, did the oil pump myself. Seeing 20PSI hot, 60-65 startup and 40+ cruising. 10 seems WAY low. DLS is a well known builder, so I imagine their clearances are pretty dead on. I would be suspect of the gauge. Its always worth trying another one.
 
I ended up going w Brad Penn 20W50 and it definitely brought it up. Sitting more around 15psi now at hot idle. I'm just going to drive it and enjoy the car. Engine sounds great no signs of it coming apart. I would have to call Dan on Monday to find out about what oil pump is on there. I know everything is new. Pump,front cover, and etc.
 
Dan at DLS is good. Just wish he would have put some baffles in the valve cover breathers he made. I get allot of oil pushed out through them. Pulling them off and having them fabricated up. Here's a temporary fix that worked lol
 

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WHTTRSH said:
Dan at DLS is good. Just wish he would have put some baffles in the valve cover breathers he made. I get allot of oil pushed out through them. Pulling them off and having them fabricated up. Here's a temporary fix that worked lol
Click to expand...

The reason your fix is working is that you restricted the heck out of the breather.

That is not a good solution as the excess pressure will be trapped in the motor and given enough pressure will blow out the rear main seal or front seal.

Make sure your fabbed solution isn't as restrictive.
 
As long as the oil pressure resounds quickly with RPM I would not worry about it. I would run Mobile1 15w-50. It's a much better oil than VR-1 IMO!

Yes be careful restricting the breathers. Time for a catch can set up.
 
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