Oil pressure
04-15-2008, 04:47 PM
#11
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Join Date: Dec 2003
Posts: 185
Originally Posted by fishman1
Originally Posted by bjuice
are you saying the oil pressure will start showing a drop in pressure as you are turning up the rpm's or when you are off the throttle and rpm's are backing down. ?
after motor was warm what was your final full throttle oil pressure?
last question, what type of oil pump is in motor now ?
after motor was warm what was your final full throttle oil pressure?
last question, what type of oil pump is in motor now ?
the oil pressure starts to drop very slowly as the rpms go up....starts at 60 psi oil pressure and dropped to 52 psi, warmed up the motor further after more dyno pulls and oil pressure started at 50 psi and dropped to around 40 psi.
The oil pump brand i am not sure as it was fairly new and i just used it off my last motor which only had 130 passes on it and i didn;t build that motor......i have a melling hv55 pump coming..........do you weld your pickup tube in or just press it in..curious how everybody does it
thanks
Just to let you know that that pump is now made over seas and the gears are junk :shock:
04-16-2008, 10:15 AM
#15
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Join Date: Jan 2005
Location: Rochester, Minnesota
Posts: 13
Little M block. Do you have internal restrictors in the block? Small restrictors and cheaper oil pump will create the pump to cavitate, open the internal pressure relief valve and bypass the oil back to the pan. If you had a clear oil pan you would more than likely see foam pouring out of your relief valve outlet on the pump. I don't believe 10550 pump is an anti-cavitation pump, I do not reccommend it on a block with main priority oiling blocks such as the Little M. You need a Melling 10552C which uses a 3/4" pick up tube, and has anti-cavitation properties.
Improper base circle cams and lifters will also cause this to happen. Sometimes the oil band around the lifter can hang belowthe lifter bore and bleed oil off rapidly and also make it cavitate.
you can easily check this by making sure you are getting adequate oil to the top end of the engine.
Improper base circle cams and lifters will also cause this to happen. Sometimes the oil band around the lifter can hang belowthe lifter bore and bleed oil off rapidly and also make it cavitate.
you can easily check this by making sure you are getting adequate oil to the top end of the engine.
04-16-2008, 12:21 PM
#16
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Join Date: Dec 2005
Location: alberta,canada
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No oil restrictors in the block and getting good oil flow on top of the block.....the pump i have is only a 5/8 inlet and only writing on it has the number 5282 on it....i phoned moroso as it is there pan and he told me with that pan and my high rpm's i should be usuing a 3/4 inlet pump.....as far as anti cavation pumps nobody has one around here and it would take 3 weeks to get.....i want to be racing before then
04-16-2008, 04:47 PM
#19
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Location: alberta,canada
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Some people on this post are recomending 5/8 inlet pump and others are recomending a 3/4 inlet pump......i am trying to understand why moroso told me to use a 3/4 inlet pump with the pan i am usuing and somebody else posted usuing a cavation pump with 3/4 inlet pump for a dart little m block.......will the flow on 5/8 pump and a 3/4 be the same and the only diffrences would be the inlet bigger to keep the pump from loosing suction
