iceman15

iTrader: (10)

What gap for a NGK TR6 plug on a mild stock LT4 build with CC503 cam? It has full bolt ons and a 11.2 comp. Any help would be great

gregrob

iTrader: (8)

.040 .

iceman15

iTrader: (10)

Sounds good, just out of curiosity what happens when you make a tighter gap? Does the motor idle different or get a better combustion?

TheDon619

iTrader: (4)

i gaped mine to .50 on a lt1 build with a 503 and bolt ons

RamAir95TA

iTrader: (2)

From what I understand, in a higher compression engine, the risk of "blowing out" the spark is high. A narrower gap provides less spark area for the intake charge to "hold onto," keeping the spark from blowing out.

SexyTransAm

iTrader: (6)

id go with .035 with the higher compression

MTBSully

iTrader: (7)

thats what my 383 11:1 LT1 is at with my tr6 plugs

iceman15

iTrader: (10)

K I'll go with the .035 gap

gregrob

iTrader: (8)

.035 is not needed for N/A but suit yourself. You want the biggest gap you can run for the best burn. Toitight a gap when its not needed is wasteful. Might as well start retarding your timing like Nitrous guys do too. I don't see what the point of building a N/A engine is if you're not going to optimize it.

Puck

iTrader: (17)

My former tuner and retired GM engineer suggested I run .035 gap on my NA H/C build with ~11.5 CR. I trust his word as gospel!

Higher compression washes out spark at high rpms, and dropping the gap from .050 to .035 like he suggested helped drivability and noticeably cleaned up the top end.

gregrob

iTrader: (8)

Im not suggesting .050 though, am I...

Its likely that .040 would have worked well in your case too.