small block chevy oil pressure

Tuesday 2nd March 2004

Anybody got any advice on normal oil pressures at speed and hot idle on these engines?

We are only showing 15psi hot at idle with my mates freshly built race engine. This does not look good to me any comments?

andycanam

1,225 posts

271 months

Wednesday 3rd March 2004

I worried about mine also but was told that 10-20psi was perfectly normal aspecially with the relativelly runny oil I run due to my solid lifter roller cam...... Mine almost instantly goes to 60psi when I rev it.

However in reality my pressure is normally maintained above 30psi on idle by the accusump system I run.

blackzr

280 posts

253 months

Thursday 4th March 2004

Rule of thumb is 12/15 psi oil pressure per 1000 rpm on a healthy Chev small block. Depending on what type of oil pump you have 15 to 20 psi at idle is normal. As you say there is a difference in pressure between roller and flat, solid and hydraulic lifter engines.

studog

Original Poster

268 posts

264 months

Thursday 4th March 2004

Thanks guys maybe all is not lost after all!

97 posts

248 months

Sunday 28th March 2004

On a freshly rebuilt engine 15 PSI is crap! Should be 40-50. What are the clearances on the mains and big ends?

Cabby

3,942 posts

271 months

Sunday 28th March 2004

jacko460c said:
On a freshly rebuilt engine 15 PSI is crap! Should be 40-50. What are the clearances on the mains and big ends?

40 - 50psi at hot idle? Sounds rather optomistic.

97 posts

248 months

Saturday 15th May 2004

Been meaning to come back to this for weeks, kept forgetting. Had a Chev on the dyno yesterday, nothing special, just built right. 45 lbs oil pressure at 800 rpm. The Boss says a really worked on one with restrictors etc will give 55-60.

andycanam

1,225 posts

271 months

Saturday 15th May 2004

It's very easy to increase the idle oil pressure by the pump spring.... but you don't want to strive for high idle oil pressure if that means high rpm oil pressure goes much above 70psi.

Also if you put thick oil in then I'd expect high idle oil pressure..... I was running runny oil with my roller cam.

Suggesting a SBC engine with sub 30psi hot idle oil pressure is badly put together is a little ridiculous.

97 posts

248 months

Saturday 15th May 2004

We use 30 weight oil and standard high pressure/high volume pumps.

97 posts

248 months

Saturday 15th May 2004

PS. Dont want to get tooooooo technical, but what is "Runny oil"?????

gdr

589 posts

267 months

Sunday 16th May 2004

Mine runs 40 psi at idle with 95 deg C oil temp, 65 psi on full chat. This with 15/50 Mobil 1 (which some say not to use, but I can't see why not once engine is run-in) It has hydraulic lifters, not roller.

>> Edited by gdr on Sunday 16th May 08:12

andycanam

1,225 posts

271 months