Here's an interesting experiment I did with ring gaps.
Many years ago i decided to try tighter end gaps to see what gives. my thinking was that tighter gaps would improve ring sealing, lessen blow-by and make the car quicker and faster. So I freshened a 8 second BB engine and set the top and second end gaps at .010"/.010".
MPH fell off a little so I tore down the engine to have a look-see. Using my magnifying glass I could see indications that the ends were butting, so I knew that "plan" didn't work.
There's a rule of thumb on gaps, .004" per inch of bore for the top ring and .005" for the second ring. The second ring gap "constant" was changed some years ago after testing showed that setting the second ring gap wider than the top ring gap improved ring sealing. Before that change, the second ring gap was always set tighter than the top gap.
For engines running nitrous or chargers, it's recommended the gaps be wider - .005"/.006" per inch of bore. This is because the higher heat created by the power adders results in greater ring expansion calling for more gap to prevent butting.
Here are some more gaps; this time taken from the 1986 (eighty-six) GM Vette FSM:
Top Compression Production: .010"-.020"
Second Production: .010"-.025"
Oil Production: .015"-.055"
Hope this helps.
My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!
1996 Vette, 388 CID LT1 (3.75" X 4.060"), Eagle Internally Balanced Forged Crank, Eagle 6" Forged Rods, SRP Forged Pistons, CompCams XFI 467 Cam (230/236 @ .050), Scorpion 1.7 RRs, AFRs ported to 212 ccs (304 cfm @.600), Match Ported LT1 Intake, SVO 30# Injectors, BBK 58mm