From:Ken Lee
Subject:RE: KJ pistons+ Date:Fri Feb 10 05:40:47 2017
Response to:6487
Morning Steve , 6 to 8 is ok , I'd ere on the larger size . My '26 DeLuxe was 12 thou when I bought it (can't remember why I had the barrels off) but put back with new rings and it's had three new sets since and doesn't smoke hardly except on over run a bit and I've done about 30,000 miles since , still runs great !! Best wishes , Ken

Dear All, I'm pulling down a 29KJ which was running before I started messing with it. Scratched in the sump is the info that it was last restored in New England in 1978, and it's seen a lot of miles since then. It has two types of alloy pistons, different bores, around 69.5 mm which I take to be about +20. The pistons might clean up and go round again in honed cylinders, but perhaps I can do better. The piston, bore and clearance advice on this forum is pretty old, but I'm seeing Simca pistons, OK to bore a bit past +20 oversize, and to leave 6-8 thou bore clearance for the pistons. Does anyone have fresher or better info, in which case many thanks.