I am building a motor which will be generally streetable (325 or so hp na) and will benefit from the occasional shot of N20. I have been told that I need to gap my rings a little larger than normal. I don't want to be chewing up rings every 10 thousand miles because of the N20. What should I gap my rings at?

 

Smash, if you are going to use over a 100hp shot of nitrous on your eng. just multiply the stock recommended top ring gap by 1.4 !
Example: Stock top ring gap = .016"
So .016" x 1.4 = .0224"

-Auggie-

 

so the top ring gap is the only one you have to worry about when considering nitrous?

 

In a nutshell, do what your piston manufacturer recommends. PERIOD. Different pistons have different ring land locations, conduct heat differently, use different gas ports… and the piston has more of an impact on this then anything else.

In theory, you need to get the top gap bigger then normal because N2O will put more heat into the ring then NA would (assuming the same ring height, of course, an N2O piston should have the top ring down lower then a standard piston). In addition, you never what to end up with the second ring having a tighter gap during operation then the top ring. Lastly, If in doubt, make it bigger. A few hundredths bigger ring gap will not make any measurable difference in power production, but you'll know if the rings expand enough to but together…

 

I set my motor up for nitrous and went with ring gaps of .024" on both the top and second rings.