Im going to start from the beginning. My engine had blown once before on a hot day at the track which resulted in cylinder 1 piston blowing a pretty big piece of metal through the head, which also after my rebuild took out my turbo. Now after about 1500 miles on the rebuild with the CP pistons my engine is smoking even at idle and compression numbers are cylinder 1: 160 and 190 for the other 3. Could it be that cylinder 1 is starting to fail again? Or possibly a head issue? But the engine a drink quite a bit of oil.

 

What was the initial cause of the piston damage before the rebuild? You could rule out valve leak with a leak down test. If the compression is leaking out the bottom then its either poor ring seal, broken ring, or a broken piston.

 

Not sure the reason it blew exactly. Just felt alot of studder then all of a suddon im running off of 3 cylinders. Here are pics of before the rebuild. I had to get resleeved because of that top ring.

 

did you hone the block after you pulled it apart? what was the p2w clearance onthe new pistons? what were your ring gaps? did you have any of the surfaces decked afterwards? did you do a leakdown test on the motor yet?

 

Detonation blew out the weakest point - the intake valve relief.

 

P2w clearance is "0.030 not sure about the rings or if the news sleeves were honed. The head and block were resurfaced and i have yet to a leak down test. Im really hoping its not the piston thats bad. Really dont want to buy a new set. The cylinder thats giving me problems has a compression of 160 with the 9:1cr pistons. Is that a bad number for 9:1 if the cylinders were the same.

 

What do you mean you are not sure if the new sleeves were honed??? Did you build this motor?

 

No i didnt. It was sent off the the local machine shop. I was in to much of a hurry to do anything myself. I was preparing for my move to germany.

 

Did you run the same tune as before that broke your last pistons?

 

No it was a completely different tune with a different tuner and on a dyno instead of street.

 

Remove the exhaust manifold and check the runners in the head if its burning a lot you'll see oil build up in one cylinder more then the others. Then move on from there with a leak down test. Nothing more you can do but rule out the problem and rebuild.