I have GSR block with built bottom end factory cylinder bore of 81mm. I decided to refresh the block with and fresh hone, new rings and bearings. I just recieved the 81mm wiseco piston rings. I was going to start filing the ring end gap to spec. So I measured the rings first to get a starting point to see what the gap was. I measured top ring first and then the 2nd ring. The top one was .0015 which is fine because I needed to file them to .0019.

But when I checked the 2nd ring it was already at .0027!!!! I didn't even start to file the ring end gap and its way to big. I needed them to be less than .0021 to start the ring gap filing.

WTF is going on! Did they send me the wrong rings? The bag they came in says 81mm.

What do I do???

 

whats your acual bore size?

 

Not sure exactly. But the machine shop did .0035 Piston to wall clearance.

Could it be possible that my bore is closer to 81.5? Thats the only other explanation.

 

anyone know?

 

You're going to need to measure the cylinders to know exactly what is going on.

 

Just called Wiseco tech help and they said It should be ok since I am forced induction. As long as the compression ring is were it needs to be the 2nd ring will be fine were its at. The only way to make it perfect is custom rings. or do 81.5 hone and change my pistons and rings.