Building a b18 for boost looking for around 550wheel .

Ge sleeved 81mm honed to .0045 ptw cp pistons

Question is. Top ring filed out at .020. Which was target. Now second ring is measuring in at .027. The book says .004-.008 bigger than top ring. In your personal experience do you think that will be fine as is?

I have tried 2nd ring from the other 3 boxes I have and they are very consistent.

 

What brand pistons and rings do you have?

I have heard of people running 2nd ring gaps that big with forged pistons and not have issues. Its the first ring that makes the compression anyways. The 2nd ring gap needs to be bigger to let any pressure that gets by the first ring out to prevent top ring "flutter".

If your 2nd ring gaps are that big out of the box what did the oil ring gaps come out to??

 

Cp

.020ish oil ring. I wasn't too worried abt being exact as long as it was between .015 and not larger than 0.050

Also I knew the 2nd ring needed to be larger then top for the reason you explained but from my calculation I had initially planned out .024 2nd ring.

Oh well it is what It is I guess

 

You are more than fine with those numbers. Have fun.

 

It'll be a little noisy on cold starts/warmup due to piston slap with a p2w that big but other than that you should be fine.

just remember to put the rings in right side up and clock them right. I've seen so many detailed ocd people forget about those 2 details during final assembly lol

 

although my bore is a bit bigger than yours, im also at .027 on the 2nd ring. its all good you are fine