New motor.. oil pressure questions.
07-16-2006, 08:52 PM
#1
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New motor.. oil pressure questions. Just got my car put back together with the new motor.
Forged 347,
Diamond forged pistons
lunati pro mod rods
stock crank
arp main studs, lunati rod bolts
clevite h series bearings throughout
and a ported ls6 oil pump
upon warm start up the car will make 55-60 lbs of oil psi at idle. today was the first day I really took it out, and I didn't romp it hard but it did see 4500 rpms a few times. Upon the car warming fully up, I noticed oil psi drop. It appeared to be 55-60 under full throttle and right at 30-33 lbs at idle. Bad thing to me was the fact that the car under 2k - 2500 rpms was only at 39-40 lbs of pressure. I noticed however that at 2500 rpms the oil psi would suddeny jump 5-10 lbs to around 48-55. It was an all of the sudden jump that was easily reproduced. however if I romped it, the oil psi would immediately jump up to 50-60.
My question is, anything I need to be worried about? or just run it? Before the car blew up before it wasm aking great pressure, 40 at warm idle and 55-60 at cruising.. so that is what I have come accustomed to.
Any input is appreciated.
Forged 347,
Diamond forged pistons
lunati pro mod rods
stock crank
arp main studs, lunati rod bolts
clevite h series bearings throughout
and a ported ls6 oil pump
upon warm start up the car will make 55-60 lbs of oil psi at idle. today was the first day I really took it out, and I didn't romp it hard but it did see 4500 rpms a few times. Upon the car warming fully up, I noticed oil psi drop. It appeared to be 55-60 under full throttle and right at 30-33 lbs at idle. Bad thing to me was the fact that the car under 2k - 2500 rpms was only at 39-40 lbs of pressure. I noticed however that at 2500 rpms the oil psi would suddeny jump 5-10 lbs to around 48-55. It was an all of the sudden jump that was easily reproduced. however if I romped it, the oil psi would immediately jump up to 50-60.
My question is, anything I need to be worried about? or just run it? Before the car blew up before it wasm aking great pressure, 40 at warm idle and 55-60 at cruising.. so that is what I have come accustomed to.
Any input is appreciated.
07-16-2006, 09:47 PM
#2
get a mechanical oil pressure gauge on it and see what it says. i have heard of people getting screwy oil pressure reading by getting the o-ring on the pickup tube pinched and not sealing properly or a machine shop leaving out a galley plug. you'd think you'd have no pressure at all if either of these were the case, but theses new sbc's are a little different.
07-16-2006, 10:17 PM
#5
one way to tell is by checking the dipstick level at idle. if you have oil pressure at idle, but the oil pan is still full, the oil pan will have to come off and see if the o-ring is pinched. if not, the rear cover has to come off to see if that rear oil plug is in place and not just letting oil run back into the pan.
07-16-2006, 11:10 PM
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That is normal pressure for a forged motor. The bearings tolerances could be a lil loose causing it. Mine is about the same as yours. They say as long as you have approx 7 psi for every 1K rpm your turning you are good.
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07-17-2006, 01:10 AM
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Originally Posted by John02SS
That is normal pressure for a forged motor. The bearings tolerances could be a lil loose causing it. Mine is about the same as yours. They say as long as you have approx 7 psi for every 1K rpm your turning you are good.
Around what exactly does yours push out? PSI wise per rpm?
07-17-2006, 03:47 AM
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Mine was doing this and I spun a rod bearing. Just a heads up. Forged 347 also. I took the motor back out with 500 miles on it and made my builder redo it. Because what you decribed is exactly the way mine was acting. And yes I put the mechanical gauge on it.
07-17-2006, 08:30 AM
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Originally Posted by JMBLOWNWS6
Mine was doing this and I spun a rod bearing. Just a heads up. Forged 347 also. I took the motor back out with 500 miles on it and made my builder redo it. Because what you decribed is exactly the way mine was acting. And yes I put the mechanical gauge on it.
07-17-2006, 11:05 PM
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Originally Posted by Boostaholic
so yours was jumping up at idle? mine doesn't seem to jump, I think part of my lower oil pressure is some of the oil goes to feed the twins
True. But my blower takes off the same way as your turbos.
