Taking apart my shortblock last night everything looked like normal wear for a motor with some miles on it, but when I took off the #2 main cap (second one back from the front) the bearing looked like someone had put it in the garbage disposal for a while, and then installed it. This motor is a four bolt main block, and was a GM service crate LT1 longblock, and was 100% factory internally except for the LT4 hotcam kit, which was installed while the motor was brand new on the stand. Is this common? And what can I do to prevent this after the motor is rebuilt? It will be turning alot more RPM after this rebuild, so I definatly dont want any oiling or bearing problems...

 

How was your oil pressure while it was running and in the car?

What caused you to take the engine out in the first place?

 

The oil pressure was ~25 at idle and would go up to ~50 under throttle. It was stable and didn't give me any reason to be worried. I took the engine out because I am upgrading the heads and cam, and firgured due to the age of the engine it was probably time to freshen the bottom end. Other than some oil leaks, it ran fine when I removed it. The only thing I can think of that I did to cause damage like that was spray a 125 wet shot through it when it was about a year old, but wouldn't that have caused damage on more than one bearing if it was going to?

 

Did anyone prime the oil system before cranking it after the initial install?
Doug

 

 

Sorry to bring back an old post, but my block and crank will be coming home from the machine shop soon, so I'm still looking for opinions on what caused this. The machine shop said "something must have blocked the oil passage" Um ok...thats not really the shot in the dark I was looking for...so why was this the only one like this? The mains on the crank had to turned down .020 just FYI....I don't want this to happen again....anyone????

 

Hell now you can take a picture of that bearing for us and post it up here.

On the crank work, it would be nice to see the radius in the corners of the journals now too see how well it was done.

Bret

 

It is not common for a factory engine to have metal shavings in the oil passages but it does happen. It could have been running like that for a long time.
I just saw a 12,000 mile LS1 with the factory bearings and they looked like someone had been feeding them metal instead of oil. That engine was running when they brought it in.No complaints about oil pressure but the complaint was low power. Engine turned fine but leak down was high.

 

Bret, I will post pics as soon as I get it pick up from the machine shop, I have been busy at work because of the holidays and such and haven't had a chance yet. BTW when I get this shortblock done I will be contacting you for a cam

racerdude, so you think I will be ok as long as I am meticulous and clean about assembling my shortblock?

 

Clean is key!

 

Yes and blow out places where there ain't no places with compressed air.Clean Very clean.
I didn't see that .020 under in your post. I hope that was just on the mains and not the rods.

 

Thanks, I will keep it as clean as I possibly can and the rod journals were taken .010 under...

 

OK,blow out everything and ya will be fine.

 

Ok, Thanks for the advice everyone