Engine is coming out-bad ring maybe

[farmtruc]

Well, I finally got the heads on and then did another compression check. Number 7 piston is still loosing compression somehow. I'm sure it's not the gasket anymore, it's reading the same amount of psi, 50.
The only think I can think of is the ring or piston is damaged. It wasn't making any knocking noise (before I tore is down) or smoking, so not sure on this one. I guess I'll pull the engine and check out that piston. The heads looked fine.

any ideas?

btw, are ARP studs reusable? Those bastards were $200+ and they better be, lol.

thanks,

allen

[ONE04FX4]

did you put some oil in the cylinder. if it is a ring it will raise the compression. i usually fill the combustion chamber with fluid also to check the seats on the heads.

[Defunct SO]

Allen, the ARP stuff is reusable.

[honkydaddy]

Put some air to it.If it's a ring you'll hear it at the dipstick.If it's a valve,the intake or exhaust pipe.Make sure the valves are closed.

[JCFREAK]

I left the spark plugs out of my car overnite one time. After I put them back in it wouldn't crank. Had to pump oil in the cylinders to get the rings to seal before it would crank.

Kevin Lucas

www.gracemotorsports.com

[RedHeartbeat]

Sounds like time to upgrade the piston rings to a set of zero gap Total Seal piston rings or at least the newer upgraded piston rings that eliminate oil burn.

[Hit Man X]

Originally posted by GREG_92_C1500_2001_LS1_A4@Oct 10 2004, 11:31 PM
Sounds like time to upgrade the piston rings to a set of zero gap Total Seal piston rings or at least the newer upgraded piston rings that eliminate oil burn.

Yup! TSS makes gapless for the 3.9 LS1 bores for the top and 2nd rings.. but not for the 6.0. They only have a gapless for the 2nd ring.

[farmtruc]

Got an update on the engine. I pulled the engine out today and checked piston #7, son of a bitch, LOL, the piston is brok and so are the 1st and 2nd rings. There's a nice big chunk of of the piston, on the side. It all stayed together nicely, then I removed it and it just crumbled apart
The wall looks ok, there is one tiny small scratch towards the top of the bore. It's about 1/4 " long and my finger nail can catch it. All the other scuffing where the piston was damaged is ok, I can't feel it with my nail, I guess that's a way to tell if it's fine.
While I have it apart, I should put some better rod bolts, and forged pistons,
what is everyone's opinion on that?

thanks for any input,

allen

[Hit Man X]

I'd go with all ARP hardware while it's out. I'd get their main bolts, studs if ya can swing them... write them off.

Rod bolts for sure! Stock rods are pretty nice, I'd keep them south of 6600rpm still as they aren't balanced or anything.

I'd check the rod bearings and main bearings, replace if need be.

I have seen a set of JE pistons fail, so I dunno if I'd go with them. They were running 18psi on an 8:1 motor. Maybe Diamond, Arias, and the like. TSS gapless rings kickass! I'd just hone the cylinders too.

Then seat them rings well. As soon as you verify oil pressure and get the motor to temp, I'd go romp on the pedal @ 50% throttle, 75% throttle, then 100% throttle. Then slow back down each time allowing the motor's vac to slow the vehicle down (2nd gear works best it seems) that will help seat them. Then I'd change the oil.

[RedHeartbeat]

As for rods, I like SCAT H-beam rods. They are about $400 but that is a lot cheaper than many others. As many passes as you probably have on the motor and the fact that you now have a turbo, I would go with new rods for sure. I think low compression pistons would be beneficial for your turbo setup so that you can go more boost without detonation. Low compression/high boost makes more power than high/normal compression with low boost.