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69SSZL1
08-19-2005, 04:24 AM
In my new solid lifter 427 motor I'm running the GM 396870 (1.3" gears) oil pump and my oil pressure is 43 psi hot at 2000 rpm and above, never higher. At idle(1000 rpm) it is 15 psi. My main bearing clearences are .0028" rods .0025". Crank is #7115. Oil is 10w-30 and 10w-40 did'nt raise it more then 2-3 lbs. Is this normal for this pump?
69SSZL1
08-21-2005, 05:38 AM
What would be normal COPO big block oil pressure?
Keith Tedford
08-21-2005, 04:59 PM
Our L78 runs 50-55 psi going down the road and around 15-20 at idle. The COPO car has the factory gauges which are pretty Mickey Mouse. Looked like about 10 psi at idle and 50 going down the road. I wouldn't count on the accuracy but the engine never had an oiling problem. I think that the L88-ZL1 oil pumps had internal modifications to counter cavitation at higher rpms. Probably something that Grumpy Jenkins figured out. Chevy oiling systems are good and don't need high pressure. I'd be more concerned about oil pan capacity. Six quart would be more to my liking.