sagres

iTrader: (4)

Well I bought a long block from a x sponsor here. Am currently breaking it in. At startup the motor sits at 40 and moves with the throttle, but when it warms up it goes down to 20 and doesnt move even with throttle. Me and my bud are thinking its a clearance issues on the crank. Other than crack this motor open any ideas what I should do? I adding some heavier oil and going to see what it does. If this xsponsor farged me Ill post his name but. I just want to fix this. The motor does not even have 5 miles on it. And the installer is a very reputable guy and has installed 100s of LS1 motors. Here is a basic build sheet. GM 6.0 block ( new )
Eagle 4.0 crank
eagle 6.125 H-Beam rods
wiseco -32 cc dish pistons
wiseco plasma moly rings
arp main studs
clevite H series bearings
Patriot 6.0 stage 2 heads
comp custom cam 234-230 .604-.598 116+2
comp 850 lifters
manley 7.400 pushrods
harland sharp 1.7 rockers
rollmaster dual timing chain
ported LS6 oil pump
It has 8.7 compression, If there is a problem. I think it was the builder but like to take some advice with anyone. What to check. If you need more info just ask. Is this normal?

sagres

iTrader: (4)

Also changed the oil and cut the filter in half and there was no shavings in it.

TT_Vert

iTrader: (12)

i had this issue w/ hot oil pressure turned out to be rod bearings. but mine did rise w/ rpms

dave

Ben R

If the pressure isn't jumping up when you hit the gas you might be looking at a real problem. Get into contact with the builder and ask them what you should do about the problem.

racecar

Sounds like a bearing clearance issue. Too much side clearance on the rods would cause low pressure also. A shim in the oil pump bypass spring will increase the pressure. I had the same issue before I shimmed .145, that's a huge shim. Now I'm pulling my motor because I built it with .002 on the mains and .0025 on the rods. It starts and warms up fine with 60 psi cold, 40 idle, and 60 at WOT. After Road racing 10 minutes, it drops pressure to below 30. I am going to rebuild to .0015 on the mains and .002 on rods. I think that you just have too much clearance, you might be able to shim the oil pump to get pressure but it will lose it when it gets hot.

sagres

iTrader: (4)

Thats what we were thinking the problem was, but we are debating on driving for a little bit and seeing what we can do. Motor is not knocking, but dam does this **** me off. Having to pull the motor and correct a problem someone else fudged. I was trying to see if someone else had a similar problem and you hit the nail on the head as to what we thought was the problem. Thanks