oil pressure
Thread Starter
Racer
Joined: Oct 2007
Posts: 431
Likes: 22
From: Chester Illinois
oil pressure
my 81 has 120,000 mi. on it. according to the guage the oil pressure is 40+ at highway speeds but at idle it will drop to around 20. is this a sign that things are starting to go down hill. oil usage is minable
Melting Slicks
Joined: Dec 2009
Posts: 3,232
Likes: 656
From: Thunder Bay
When you get down to less than 10 lbs at idle you might want to start worrying about it, but what you have is fine. I've had more than one small block chevy with less pressure than you have that just kept on going.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
A Chevy small block engine when NEW would read 15-20 psi at idle...some might even be near 10 psi. The engine is not 'loaded' at idle speed and doesn't need much pressure to be adequately lubed. Chevy Engineering tried to create an oil pump that would be durable, reliable, and NOT create excess work (fuel usage) or heat when it is not needed. 40-50 psi at cruising speeds is normal, also.
The fact that the vast majority of C3 vehicles that are still around continue to have the original oil pump in them...and working just fine...is a good indication of just how good of job Chevy Engineering did with the small block V8.
I am constantly amazed at the folks who purchase one of these machines that continue to work well for about 4 decades and decide that the oil pump which is still working flawlessly "needs" to be replaced by some hi-flow, high work, and high dollar "racing" oil pump.
Go figure....
The fact that the vast majority of C3 vehicles that are still around continue to have the original oil pump in them...and working just fine...is a good indication of just how good of job Chevy Engineering did with the small block V8.
I am constantly amazed at the folks who purchase one of these machines that continue to work well for about 4 decades and decide that the oil pump which is still working flawlessly "needs" to be replaced by some hi-flow, high work, and high dollar "racing" oil pump.
Go figure....
Last edited by 7T1vette; Nov 3, 2013 at 09:57 PM.
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,595
Likes: 7,043
From: New Or-leens Loo-z-anna
My '93 SBC has 216,000 on it.....at about 3500 miles on the engine oil---the idle pressure slowly drops from 25psi to 15psi near the end of the oil "life".
I change the oil & filter every 4,000 miles---approx. every 4 months.
I change the oil & filter every 4,000 miles---approx. every 4 months.
