557 SV piston

[tony.barnett]

Ray - did you have any joy finding a suitable replacement piston? I'm looking too now.

[RayBlack]

Hi Tony. The only source of repro piston I could find is JP. They appear to have standard up to +40 sizes. The barrel I have is in pretty poor shape so I am still keeping an eye out for another with not so many broken fins to repair (yes, I know, good luck with that...). I am also remaining optimistic there are a few Hepolite 1109s out there still waiting to be discovered.

[tony.barnett]

I'm going to try to rescue my standard piston - the top groove has spread a little so the clearance now is causing rings to break - I'm going to widen it a tad and get a wider ring made to fit. If not it'll be rebore and JP. I'll keep an eye out for 1109 pistons.

[nevhunter]

You can put two rings in the widened groove. Works fine. Nev

[tony.barnett]

You can put two rings in the widened groove. Works fine. Nev

Its been running for ten years with two 1/16" compression rings in the top groove, but after an `episode' it appears to have spread the groove a little so there is too much play now and its breaking rings.

[nevhunter]

It won't wear the groove any more than with a single ring. Carbon in the groove or not enough end gap breaks rings. SV motors run very hot especially near the exhaust port. A "twisted" con rod will make the rings wear more and having no air cleaner. Nev