123 Ignition Best Spark Plug Gap?

[Sharktrainer]

As the title says. Using non resistor plugs

[zinz]

Factory is .024 - .026"...? Electronic igniters like Hotspark and Pertronix allows another .01 larger gap. 

 

I run 0.035" on NGK BP6ES plugs and the 123. 

 

I know others have done some experiments and they settled on something closer to 0.030"

 

Hope that helps,

 

Ed

 

[AlanM]

I run an aftermarket quad throttle EFI system using wasted spark on a twin coil set up, and have experimented on the dyno with plug gaps on a fairly modified engine. In my case at least, with a 121 head, there is no increase in power beyond 36 thou, going up to 44 thou with no misfire, but no Hp gain. I use NGK Iridium single earth electrode plugs. I think you could safely run 30 thou with your set up.

[Dudeland]

I have a 123, MSD6A with the corresponding coil and I can run up-to 45 but i noticed no difference, and the smaller gap worked better for starting. 

[Sharktrainer]

My W5DC arrived finally. Guess I'll gap at .030" and hope it's good because a bit of a PITA to change with turbo manifold in the way.