Cruzinimage Big Bore Pistons

[dps650rider]

Does anyone know what the minimum piston clearance and minimum ring end gap specs are for the 78mm pistons they sell? I have a set and there is no paperwork with them at all. Since the pistons appear to be cast wouldn't stock specs be about right possibly allowing a bit for the increased bore size?

 

[Jim]

Does anyone know what the minimum piston clearance and minimum ring end gap specs are for the 78mm pistons they sell? I have a set and there is no paperwork with them at all. Since the pistons appear to be cast wouldn't stock specs be about right possibly allowing a bit for the increased bore size?

For that small of a difference in diameter... and as you said, both are cast... I'd just use the same values.
The difference in size is about 2.5% larger. Adding 2.5% to the clearances would be miniscule.... not worth the bother.

 

[dps650rider]

What about the ring end gaps. I never understood why the stock spec is 0.008 minimum but with the JE's I have the spec is much wider at 0.013 minimum.

 

[Jim]

Not sure what you're referring to with "JE's"...

 

[gggGary]

Not sure what you're referring to with "JE's"...

JE brand pistons?

 

[dps650rider]

Yes 77.5 mm JE pistons.