OK so Ive been following some of the recent oil consumption problems many of us are having, mainly Chris N's thread(great post by the way, lots of good info), and Im gonna take a guess and say that my oil rings are probably shot to hell.

The reason I think this is because I was finally able to gauge how much oil Ive been losing. Over the past 600 miles, I went through over 1qt of oil. That was all highway driving, with very little v-attack. I get no smoking whatsoever under idle, the ONLY time I get smoke is if I romp on 1st gear hard, or if I downshift hard. Otherwise I NEVER notice smoke, however my bumper is blackened after a full tank of gas. Ive tried other oil brands and weights, and nothing seems to change.

Ive got aftermarket pistons, and my compression is fine, but Im pretty sure the rings were reused from my stock pistons(I think, but am not sure). Only other thing it could be is blow by or valve seals, both of which I think are supposed to produce smoke even at idle (correct me if Im wrong).

Now to my question, when replacing rings, do you HAVE TO have the cylinders honed out again? or can I just swap rings, and slap the pistons back in? I know that when the motor was rebuilt, it was honed, but not sure if thats standard practice for any bottom end work. Basically I just need to know if I can pull the rings, and replace them, and slap it all back together or not. The motor has about 40K, but only about 10K after the rebuild.

Sorry for the lengthy post

 

How many miles are on your car since the piston install?

 

If you're still using a 81.0mm bore that's most likely your issue...you changed the pistons and just rehoned the cylinders, it works some times, and it doesn't work in others. I'm surprised that you didn't bore out and hone to a 81.25/81.50mm when you went to aftermarket pistons and had them install new rings.

What break-in method did you use, what oil?

Austin

 

10K on the motor since the rebuild. And I wasnt up to speed on things when I first got the car so I didnt notice how much I was burning and I dont remember if it was a problem before the rebuild.

The motor was broken in on the dyno. Like literally, 25 runs before the car was even driven after the build. It was started once or twice after the rebuild, but that was with the stock ECU and it wasnt able to run the car on the larger injectors so it would just stall. Then the ECU was stolen and I went with AEM EMS and tuned it on the dyno the first day.

I didnt go overbore on the pistons because I didnt know any better at the time. If you think it is a bore issue, wouldnt the compression rings be affected as well, therefore, I would have crappy comp readings? My comp ranges around 280ish across the board.