Normal oil pressure for OMC Cobra 4.3

[chashman]

What should the normal operating oil pressure be for a 91 OMC cobra 4.3l. I have noticed mine stays at 40psi while idling, while cruising at 3400 rpm the oil pressure jumps to 60psi and at WOT the pressure gets to 80psi. I am trying to figure out if that is normal. I checked the oil level and with the motor level, I was 3/4 of the way between the full line and the add 1 quart line. Thanks

 

[Mkos1980]

Re: Normal oil pressure for OMC Cobra 4.3

Little high but nothing to worry about, but your probebly going by the stock gauge and not a good mechanical one.. The pressure will ALWAYS be higher with more RPM's. Your turning the oil pump faster.

 

[Gary H NC]

Re: Normal oil pressure for OMC Cobra 4.3

Sounds about normal to me too...

 

[a70eliminator]

Re: Normal oil pressure for OMC Cobra 4.3

Generally you want to see a minimum of 10lbs per 1000RPM. Electronic resistance senders vs hydraulic as well as the gauge error and viscosty of oil and temperature can make number comparisons all different, your gauge tells you whats normal for your engine, 80# WOT is not a normal reading for my engine.

 

[cr2k]

Re: Normal oil pressure for OMC Cobra 4.3

Not sure about the 4.3 but an old school Chev V-8 will blow the cam bearings around 80 psi. I have seen some 4.3s near 80 however. If you are not having problems don't worry. Most likely your gauge or sender is a little off. pull the oil sender and stick on a mechanical and see what it really is.

10 is a little low at idle but useable. A decent 4.3 idles around 15 to 20 psi. and runs at 40 to 60. All depends on clearances on oil pump and bearings.