NPR Piston to Wall clearance?

youre getting it machined. you decide what you want your p2w to be

"the factory spec is .0004"-.0016"" - Drag4life723 circa 2009

I've got PM6 pistons, at 75.5mm bore, but in a Y7.
Looking back at engine build notes, mine were all right at .001”
In addition, the only method I had to measure this was at the top of the bore/deck surface, measurement made between the bore surface and piston skirt.

I’ve had my head off this engine since the build, and ~30k miles in, the cylinder walls looked Very nice. Cross-hatching still present everywhere, no scoring, I was pleased.

Hope this helps!

slo_eg8 said:

youre getting it machined. you decide what you want your p2w to be

"the factory spec is .0004"-.0016"" - Drag4life723 circa 2009

Click to expand...

Yes, but I didn't know what the best p2w is

I had to convert .0004"-.0016" into metric, so it's 0.01mm - 0.04 mm
The seller of the pistons told me the clearance is the same as OEM and it's 0.035mm

I told that to my Engine Builder and he said that 0.01mm is too tight, but 0.04mm is common in most engines.
So I'll go with that

0.001 is good through 200 HP from an NA D series.