My friend's JDM B18C blew a ring land and ring in the #4 piston. So he decided to go w/ lower compression pistons with his turbo. He went with JE 9:1 pistons 81mm (stock bore), eagle rods, and JE piston rings, JE wrist pins.
The piston rings were machined to specs and they were all placed correctly in the right place and w/ the "JE" stamp facing upwards.

It started up and idled like crap. Runs like crap too. Motor was never pushed at all. So from a leakdown test we found out that there was:

60% leak in cylinder #1
30% leak in cylinder #2
50% leak in cylinder #3
10% leak in cylinder #4

The head has been taken off and pressure checked and it came back fine. I also loaned him my head to test and it came back fine. Still it idles like crap and runs like crap. So what could be the source of the problem? Nothing looks out of the ordinary. Could it be a bad piston batch? Did I receive wrong rings? Thanks for the input.


Joe