Club pistons for G9/Mod 20

[Groily]

Piston questions on both my 500s solved using original bits, with the last pieces of the equation being Rings.

In the end I had one pair of barrels resleeved by T & L and bored to +20 to take a good pair of AE pistons from Steve Surbey (but the rings on them weren't as good as we'd both hoped); the other pair of barrels, surprisingly to me anyway, were still very close to spot on and didn't need to go out to +40 as I'd expected. But, the rings were shot to hell with seriously huge gaps and lack of radial springiness.

So, good cylinders and pistons were to hand - but no good rings for either engine, particular problem being the 5/32nd oil rings.

First result was a pair of truly NOS +30 Wellworthy rings courtesy of Steve at AMC Classic Spares again, which were easily regapped and work a treat, and second result thanks to FW Thorntons (thanks to Spriddler for suggesting them, you were spot on mate) who have a good stock of 66.5mm 5/32nd oil rings, with correct radial thickness. (They also have 66.5mm 1/16th compression rings, but with a radial thickness of 10 thou bigger, and can also notionally do rings for a lot of other AMC twin sizes.)

For the moment I'm running the best mix of rings from my stock in the 2nd engine (not ideal as the gaps aren't that great) and the re-gapped new +30s in the other. The Thorntons oil rings will go into the sub-optimal engine when they arrive. 8 pounds something the piece.
(Plus, as a result of this exercise I am now the possessor of various other pistons and bits for future use, thanks to kind folk here.)

Anyone know - anyone tried to do it - if there's enough meat on BHB and/or AE/Hepolite pistons safely to take out the ring grooves 10 thou to accept the radially-thicker compression rings Thorntons sells? (I've done it on a car engine before now with no problem, but that was a slightly different matter). Because if that's feasible, reckon I've got enough bits stock-piled now for the rest of my natural . . . . not to mention a mounting pile of heads and valves and guides . . .

Thanks again for help and info to one and all.