PISTON RINGS FOR G3LS 1959

[PhilipSpicer]

Some advice please:

On re-assembling after de-coking piston and new exhaust valve etc I managed to snap the upper piston ring while lowering the cylinder barrel onto the piston.
So I bought a standard piston ring set for the 350 Heavyweight from AMOC Spares. But they are very slightly wider and come with a sticker saying 'only fit with GPM Gandini pistons'. I do not think my 59 G3LS has this piston (it has no markings to identify it, just the letters AM413 4369) - and I am worried I will cause damage to the bore if I fit the slightly larger piston ring.

I see the AMOC Spares list for engines has 20 thou and 40 thou rings also available, but any advice gratefully received before I end up with three sets of rings!

Many thanks, Philip

[g80csp11]

send broken ring to cox and turner and they will provide a ring to fit . sounds like you have a metric ring replacement
its important its correct .
https://www.coxandturner.co.uk/piston-rings/

[clive]

The othe rings on the AMOC spares site will be the same width. The +20 and +40 refer to the bore and they are for bigger pistons in a rebored barrel.

[PhilipSpicer]

That's great advice, I'll get in touch with Cox & Turner. Thanks very much, Philip