Hello, i have an 05 lm7 swapped into a 93 300zx with a turbo in the car. At first i just installed the stock engine into the car to see what i'll do, ended up with a spun bearing after a couple of weeks of beating the car. I figured it happened because of the unknown milleage of the engine plus the stress from the turbo. So based on that, i did new clevite bearings, new meilling pump and not so new but std size crank. So i did about a week of tunning/testing at about 8 psi and i just heard a bearing again. Is there anything that im missing on this set up for a propper lubrication? I always have at least a quarter of extra oil in the pan and the return for the turbo is on the front timing cover if it matters. Thanks

 

It bears repeating- Was the oil pump pickup O-ring properly installed?
ALSO all gallery plugs in the block?

 

I'm going to do the disassembly on the weekend, i want to know what to look for. I'll get some pictures.

 

Yeah if you had 8psi max, there IS a problem. Likely something I mentioned above, would be surprised if different. BUT you never really know until you KNOW.

 

I think the 8 psi may be reference to boost?
I am wondering what the oil psi was, before the last failure.

 

On second thought, you are probably right! Had the blinders on....
But yeah, a note about where the OIL pressure was would have been nice.

 

Yeah im talking about the turbo psi, my oil pressure was right at 40 on start up and about 65-70 on light cruising. As far as i know that about average for a gen 3 engine.

 

Your oil pressure is good! Did you check all the clearances or put it all together and figured it would be right?

 

I had a local machine shop do the short block and i just did the top end. im going to open it up in saturday to see what's up.

 

" right at 40 on start up and about 65-70 on light cruising. As far as i know that about average for a gen 3 engine. "

Not close, unless the system has been modified.

 

when you say not close, do you mean that it should be higher or lower?

 

those pressures sound very good. My newly rebuilt ls6 with a SLP ported pump runs about 49 psi idle

 

Who put the bottom end together? What were the clearances? Was everything checked with mics? A lot of people use plastic gauge then wonder why the bottom spins a bearing.

 

This raises a flag for me. What do you mean by this? Was it machined at all? Polished or anything? I'm curious if it's the same cylinder that spun. A spun bearing can ruin your main caps and bore. Did he check this or line hone the bottom end?

 

Thanks for your input; the crank was just polished by the machine shop that build the short block.