Piston ring size

[Marine240z]

Hi all,

I am currently upgrading my engine.  Port/polish, bore 83.75, stage 2 cam, racing springs, lifters, lash pads, kameri sprocket etc.

My pistons rings are 4mm x 2mm x 2mm.  I ordered the Perfect Circle ring kit that was available for the Silvolite pistons.  The rings when I measured them were 4 x 1.5mm x 1.5mm.    According to the tech from P. C.  this 0.5 mm variance was a designed to accommodate additional expansion properties and is not an issue.

Anyone familiar or have any idea if this is correct.  Or should I opt for a ring that is 2mm.

 

Thanks

Lon  

[Zed Head]

The rings should fit the groove in the piston, so 1.5mm could be right if the groove is 1.5mm.  There's a spec. for side clearance.  Too big and the ring will get slammed up and down as the piston moves.