My recently completed swap has contracted the smokes after a few hundred miles and two auto-x's. It only seems to happen when I take it north of 6500 rpm. The smoke eminating from the tailpipe seems fairly light in color. Perhaps a light or whitish grey. A friend suggested that it is either valve stem seals or piston rings. So it looks like I should do compression and leakdown tests to diagnose it? Any feedback would be appreciated. The engine is a OBD1 JDM B18C. Gracias!

BTW: Since completion of the swap, I've thought that the top end of the motor wasn't performing as it should. If it does turn out to be piston rings, might that be the cause of the lack of top end? I'm thinking that at the high rpm's, the rings aren't holding up to the compression, letting pressure pass by and thereby reducing performance. Does my logic track with internal combustion physics?

 

Anyone have any thoughts, comments, or advice pertaining to the above-mentioned problem?

 

Any smoke on start up?

 

Nope, just when driving the car past 6500 rpm.

 

do the compression and leakdown tests done and post your results

 

It could also be your pcv valve. Check your IM to see if there is any oil inside. A safe and cheap insurance down the line is to build an oil catch can.