427 CBB oil pressure

70RS/SS396 · 01-31-2012, 05:06 PM

Hi

I have a 427 cbb motor, 80s stocker built. L88 with stock L88 camshaft.

The motor have a stock GM modified oil pump (anti-cavitation grooves).

The oil pressure is very stable, about 18-20 psi at idle and then it goes up to about 42 psi when I hit the throttle. but then even If a run the motor in 7000 rpm I never have more then 42 psi oil pressure.

I run quaker state 20w50 mineral oil. Have also tried 15w40 mineral, but with no difference.

The motor ran straight 40 quaker state oil when it was raced in the 80s.

Is it safe to run this motor with the low pressure? with the 20w50 oil.

Thank You

Alan Roehrich · 01-31-2012, 05:33 PM

I'd want to look at the oil pump and find out about the clearances, as well as the condition of the bearings.

The idle oil pressure is fine, for a hot idle at 750-1000 RPM, but the high RPM oil pressure is a bit low for 20W50.

You may well get by with it, but it is not what I'd call ideal.

70RS/SS396 · 01-31-2012, 05:51 PM

Quote:

Originally Posted by Alan Roehrich

I'd want to look at the oil pump and find out about the clearances, as well as the condition of the bearings.

The idle oil pressure is fine, for a hot idle at 750-1000 RPM, but the high RPM oil pressure is a bit low for 20W50.

You may well get by with it, but it is not what I'd call ideal.

Is it better to run 15w40 ?

Alan Roehrich · 01-31-2012, 07:14 PM

Quote:

Originally Posted by 70RS/SS396

Is it better to run 15w40 ?

I don't know that 15W40 will be any better.

I'd suggest you try 20W50 Racing Valvoline, or Brad Penn, if you want to run mineral base oil.

tj310 · 01-31-2012, 07:32 PM

Try it with 10- 30 if it's the same I say your OK---Trevor

SSGN · 01-31-2012, 10:12 PM

Bad oil pressure gauge???Been their done that,just a thought

Kevin

01-31-2012, 05:06 PM	#1
70RS/SS396 Junior Member Join Date: Jul 2008 Posts: 7 Likes: 0 Liked 0 Times in 0 Posts	427 CBB oil pressure Hi I have a 427 cbb motor, 80s stocker built. L88 with stock L88 camshaft. The motor have a stock GM modified oil pump (anti-cavitation grooves). The oil pressure is very stable, about 18-20 psi at idle and then it goes up to about 42 psi when I hit the throttle. but then even If a run the motor in 7000 rpm I never have more then 42 psi oil pressure. I run quaker state 20w50 mineral oil. Have also tried 15w40 mineral, but with no difference. The motor ran straight 40 quaker state oil when it was raced in the 80s. Is it safe to run this motor with the low pressure? with the 20w50 oil. Thank You

01-31-2012, 05:33 PM	#2
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,106 Likes: 1,564 Liked 1,789 Times in 408 Posts	Re: 427 CBB oil pressure I'd want to look at the oil pump and find out about the clearances, as well as the condition of the bearings. The idle oil pressure is fine, for a hot idle at 750-1000 RPM, but the high RPM oil pressure is a bit low for 20W50. You may well get by with it, but it is not what I'd call ideal. __________________ Alan Roehrich 212A G/S

01-31-2012, 07:32 PM	#5
tj310 Member Join Date: Sep 2009 Location: Dresden On. Canada Posts: 460 Likes: 0 Liked 0 Times in 0 Posts	Re: 427 CBB oil pressure Try it with 10- 30 if it's the same I say your OK---Trevor

01-31-2012, 10:12 PM	#6
SSGN Senior Member Join Date: Feb 2006 Posts: 644 Likes: 131 Liked 140 Times in 51 Posts	Re: 427 CBB oil pressure Bad oil pressure gauge???Been their done that,just a thought Kevin

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