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I am having oil pressure problems with my bbc . have 9 qt. canton
oil pan,hv pump,filter adp. with no bypass,k&n oil filter and using
kendal 20-50w motor oil. all is ok to 5000 rpm 80psi . when i stand on the gas 6000rpm + oil pressure starts to drop and will
hold @ 20psi then when i back off to 4000rpm and hold @4k oil pressure climb back up to 80 psi . block temp. @ 170 deg.
Sounds like you need more oil capacity.
I dont know but that much oil in the top end seems like alot to me?
It could be too much oil on top. It could be oil pickup too close to pan bottom. On a Canton pan, it is more than likely whipping the oil up the back of the pan with the crankshaft and keeping it away from the pickup. Just like a mixer does in a mixing bowl with batter. That is quite common with those pans.
Solution, Pull the pan off and put a Moroso Oil pan baffle between the oil pump and the main it is bolted to. This will more than likely solve the problem.
squirt,
There's a possiblity that the crank is foaming the oil due to too much in the pan. I've had that situation happen before but it happened at around 5000 rpms.
thank you every one !
Before you go pulling the pan, try a synthetic oil. We had a similar problem with a turbo race engine I built, that had about 22 qt oil capacity, with a super deep sump, correctly positioned pick up, and windage trays. You didn't say if you might be running in colder water, but our problem occured at an early race in the season, when the water at the Colorado River was still pretty chilly. Give the synthetic a try and let me know what happens.
Barry
agt001@aol.com
I was told buy a reputable perf. engine builder that he doesn't use hv pumps because they pump too much oil to the top of the engine at high rpm ,maybe it's sucking it dry. ala Oldsmobile at 4000 rpm.(but the olds sucks dry for other reasons)
Did you disassemble the pump and inspect the clearances? Using an oil pump "right out of the box" is a crap shoot at best. Even the high dollar units. Although there are different names on the boxes, there are only a couple of manufacturers that actually "make" them. I have never found one unit that was "all there" right out of the box. If the clearances aren't almost perfect, the pump MAY start to work against it's self at higher RPMs. Look in the oil pump section of the BBC bible for more info...............Moneypitt