I'm running a fully built B18C1, 10:1CR with a T70 drag CRX max boost at 25PSI(will be up to 30-35) once I get this problem solved. My question regards plug gap. I'm currently running a .035" gap on NGK racing plugs (extremely cold plug, electrode is almost sitting inside of plug housing). Recent problems have been missing in 4th at top track. All other gears are perfect. 4th almost sounds like a rev limiter but will still rev to redline. Logs show there is plenty of fuel and no detonation. I run VP C16 fuel. I will be regapping the plugs to .030" and go down from there if problem still occurs. I have an MSD Digital 6 box with a blaster HVC coil. Let me know what gap and plug you are running to light off a 25-30PSI combustion. Thanks.

 

use plug r5671-a number 9 or 8

Gap them .028 and run it there should be fine with digital 6 and that much boost