I'm about to build my engine and was calculating my ring gaps, I have akerly & childs xtreme rings and my engine will be seeing about 18 psi of boost. 3.903 bore.

Here´s the recommendations from A&C
Top Rings for Supercharged Fuel/Gas .008 per inch of bore
Second rings for Supercharged Fuel/Gas .0065 per inch of bore

This makes top ring .031 and second .025, I've read second ring gap should be larger and would really appreciate your opinions about the gaps for 18 psi of boost. Thanks

 

Anyone?

 

When I talked with Mahle, they gave me similar recommendations. I was a little confused because of what I had heard in the past and what was on their install sheet, being that the second gap should be larger. So to be sure, I called for the third time and talked to someone else, and they backed up the initial recommendation. I think I ended up with .030 top and .025 second (off the top of my head).

 

Speed-pro has tables on their site which explains their shift into the larger 2nd ring gap and has the calculations.

Jim

 

If you do a search in the internal engine section you can read all about this. But what I remember is 2nd ring gap= bigger, is a newer theory and is able to increase horsepower. Smaller second is older theory.

Kp has thouched on this before