Jimmy P

iTrader: (177)

The motor has about 2,000 miles on it since it was built in August of 05. Its a new ls6 block, was bored/honed, decked, and installed 3.905 JE pistons and crower rods, used stock crank. We got the motor dynoed, but at higher rpm's the power would knose dive. We attributed that to possible valvetrain issues, as it had 7.4 pushrods in there, while the heads and block were both milled.
Well I took it to a reputable installer to change the heads/cam and to install a procharger, and he found two of the cylinder walls are scratched. I haven't seen it yet, but want opinions on what to do. I am not sure how deep the scratches are, or if there is a way to measure them. He told me one of them is about two inches long. What could happen if I keep driving it as it is? Can it not realy hurt anything as long as they aren't too bad? What could cause this?
The same week that the motor was built and I changed the oil, I found a piece of a rocker arm bearing and another piece that may have been a rocker truniun. I couldn't figure out how the rocker truniun got in the oil pan, as it was a good size chunk of metal. I guess these parts may have scratched the cylinder walls.
The motor didn't smoke, so I dont think the piston rings could be bad. Any advice on what steps I should have the installer do? I called up my buddy who has been a mechanic all his life, and told me it depends on how deep the scratch is...
I realy dont want to take it to the machine shop to take it apart and hone it. I dont think I could afford that the moment. I just want the motor to last until the summer.

01350ss

iTrader: (18)

pics would really be helpful here.

redtail2426

iTrader: (10)

i would say its probably not a big deal but it only has 2k miles on it,which means whoever built it might not have kept it clean enough.The number one cause of engine failure it dirt/contamination.Try to find out what cause it and then go from there.

boondiggys

iTrader: (165)

if theres a scratch, its not going away, if anything it will only get worse...what you dont want to happen is the scratch blowing up a ring and thats the end of your motor..you dont need anything special to take it apart...i would take it apart myself and bring the parts to the shop to be cleaned and reassembled...i thought to run a compression test through the cylinders but you already tore the heads off...lets see some pics

Jimmy P

iTrader: (177)

The first pic isn't realy a deep scratch, but shows a lot of wear for a motor that has about 2,000 miles on it.
The second pic is the scratch. He said his finger nail would get a lil caught in it. He also mentioned that some of the lifters had a harder time going in than the others. What do you guys think? It sounds like the block has some issues.

GuitsBoy

iTrader: (4)

Many motors will develop this, but usually not after 2K miles. Maybe it was caused by dirt, maybe a misfiled ring. youve gotta decide wether its worth the trouble to rehone and re-ring, and possibly need to change pistons again.

oange ss

iTrader: (50)

or piston scuffing