Surface gap spark plugs

[oldjohnno]

Downside to surface gap sparkplugs, is they will foul faster as they run cooler.

That's why they need a high energy ignition with a fast rise time - to fire them when fouled. Being fouled is almost "normal" for them. In many applications - like outboards - they are chronically wet and/or fouled. The intention was to have a plug that would keep firing after prolonged very low speed running (eg. trolling) yet not preignite when running at full throttle and high loads. The combination of CDI and surface gap worked well, and I've had success using them with methanol two-stroke bikes that will continue to fire perfectly no matter how wet and oily they are.

[Lctoliver]

Would I be wasting my money buying a set of surface gap plugs to use in my 2012 Mustang 3.7L V6? Everything under the hood is stock, I've made no modifications to it... yet.

[F120]

don't bother putting them in a car engine expecting any performance benefit

I have used surface gap plugs before in 2 stroke engines where the spark plug is a factor for the combustion chamber shape and volume

[Geoff2]

The ONLY way to find out if a particular spark plug is an improvement in your engine....is to try it.

[Walter R. Malik]

Does anyone have any experience using surface gap plugs? I realize they need additional voltage to fire over the standard type. I may have a clearance problem, and these seem like they night help. Anyone?
Thanks
Jim

I used them a lot in 2 stroke outboard motors and tried them in a tall dome big block Chevy. They work well if the ignition system is up to it.

[jake197000]

I think the reason they are used in 2 strokes is because the piston comes so close to the head there is no room for the ground strap.i used to drag face snowmobiles on 1/4 mile on ice and the piston to head clearance was .050-060.151.8 mph was my mod sled 138.2 was my improved stocker.maybe bragging a little but won many trophy and championchips.this was1994-98.

[jake197000]

I used stock coils never any problems. Burned a couple down you don't know how far you can push it unless you do
274hp 1000 cc.

[inline6]

Ran them in a high compression 17-17.5:1, all iron(block and head no water), alcohol, NA, MFI, pulling I6 based on what NGK recommended for this application. Seemed to work ok, this was a while ago but as I recall they were expensive plugs.