Once on a while I will have a pump that fluctuates specially if the idle is not stable and it is choppy. You have to remember that these camshafts have lots of overlap and you will have an extreme choppy idle. I tune my engines to idle between 1600 ~ 1800 with the highest vacuum reading I can get, if it is a Holley, I check the transfer slot and most of the times I drill the throttle plates.1972ho wrote: ↑Sun Apr 11, 2021 4:57 pm Nhrastocker I have already caught that bypass valve sticking and when I pulled it apart it was stuck open so I cleaned it out and ran some emery cloth around in it and the valve itself and it was really free to move when I put it back.I just wonder why the oil pressure does this little fluctuations cycling stuff idle.Does your oil pressure cycle are is it rock solid I know some it is the way the engine idles because of the camshaft is really radical.
Low volume oil pump
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nhrastocker
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Re: Low volume oil pump
Re: Low volume oil pump
nhrastocker that’s about where both my holley and QF carburetor idles and it sounds like you know what I mean about this low volume oil pump and how the pressure fluctuate’s.I just really needed to know if it was something that I was not the only one noticing it.But when I run my modified standard volume pump it doesn’t fluctuate as much.Thanks
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nhrastocker
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- Joined: Mon Jan 14, 2008 12:21 pm
- Location: Arizona
Re: Low volume oil pump
You stated you were idling at 1500 RPM. Have you tried setting the idle at 1700 ~ 1800 RPM's and see where the oil pressure climbs?1972ho wrote: ↑Mon Apr 12, 2021 5:56 pm nhrastocker that’s about where both my holley and QF carburetor idles and it sounds like you know what I mean about this low volume oil pump and how the pressure fluctuate’s.I just really needed to know if it was something that I was not the only one noticing it.But when I run my modified standard volume pump it doesn’t fluctuate as much.Thanks
Also, what oil weight are you running?
I have Stock and Super Stock engines running 15 ~ 20 PSI at idle with 5W and 10W racing oil and the bearings look like new.
Re: Low volume oil pump
My engine idles at over 1500 rpm and the oil pressure at 180 degrees water temp is 45 to 50 psi after running for about 10 minutes are so but when it’s cold 60 to 70 psi with 5/20 oil