I have been out of the H22 race for a while now and remember that they have FRM sleeves from the factory and there was a lot of stuff surrounding sleeving the block to use forged slugs, and then wiseco had a set of pistons that were supposed to be compatible but they were questionable and now it seems mahle makes a "gold" series piston that is compatible, can someone point me in the direction of some of the info around this? Maybe a thread or even a place that distributes them? I am torn between bumping the compression and staying N/A or dropping it to for F/I but either way if I can avoid sleeving the block I would like to. If the real answer is still "unless you want it to blow up, sleeve it" then I would like to know that too...

 

they have been out for a few years, they work for most people but some have had trouble with the piston eating the cylinder wall.

JE appears to also have an FRM compatible piston.

hit the search button and search for MAHLE in the forced induction forum and you will find a good thread.

 

Mahle bought out Cosworth back in 2004, so I guess they aquired all Cosworths technology they had put into developing the FRM compatible pistons for JUN.

I'm running the Mahle N/A pistons, and so far so good . Also check out the Naturally Aspirated forum, there are more people using them than you first think. I've yet to see any 'OMFG they destroyed my engine!!' threads.

 

Do an archived search. There's tons of info and even a monthly update thread in the FI forum on this.