Spark Plug Gap Thoughts

[340challconvert]

Spark Plug Gap Question


Installed the Edelbrock Performer RPM aluminum heads #60179 designed for the 68-73 340 engines onto my newly rebuilt "close to stock" specs 1970 340 engine.

Engine was bored 30 over as a clean up with new pistons

Initial start will be with points ignition

Edelbrock recommends the use of Champion RC12YC spark plugs with these heads. No recommendation on spark plug gap. Purchased the plugs; I was going to gap at the usual .035.

Any thoughts on this appreciated.

Phil 

[MoparLeo]

All that and still point ignition ? Upgrade to standard Mopar electronic. Runs smoother, more coil saturation, can run wider plug gaps. Go Platinum for best results.
.035 is standard for copper plugs and standard ignition.

[moreparts]

I just put in a set of plugs the other day.  Yeah, if you're running points I'd stick with .035 gap.  I did 040 with mine.  I replaced my original 30 year old Pertronix with a new Pertronix III and said it could be increased by .005 so I took advantage of that.  I think it's burning more efficiently too so I had to lean out my carb a bit.

[340challconvert]

Thanks for your thoughts guys!
I plan are starting the car with the original points ignition distributor; I wanted to avoid any starting issues since all the engine wiring was removed when the engine and trans were pulled, cleaned and then reinstalled. I have a factory electronic ignition kit I bought years ago and will install EI once I know everything else is functioning properly. Did not want to alter the wiring before seeing the car run. Car has been off the road since 1984.
Looks like for the moment, .035 gap for now, then reassess once the rebuilt engine is run and broken in. 

[RUNCHARGER]

I've experimented with spark plug gap before with no increase in performance, and I wouldn't tax a point setup with a larger gap to fire across. You have to believe the factory engineers had the optimum gap figured out for performance and reliability. Basically if you fill your oven with gas and decide to stick your head in there, striking a 1 inch match will have the same effect as flicking a BIC lighter.

[ignition1]

I use a stock point setup at .035, up to .045 with high performance inhibition setups.

[HP_Cuda]

I pushed mine up to .45 but I have a hot ignition.

Trust me you don't want to get zapped with this one.