surface gap sparkplugs

[kingsburgphil]

Perhaps one or more of the "Lounge Wizards" out there can relay the pros and cons of the use of surface gap plugs in a healthy NA motor. The technology dates back some 40 yrs. in oily 2 strokes with CD ignitions (Kawasaki 500, OMC outboards), then why not 400 hp. nitrous motors
that can break off ground electrodes at shift points?

Assuming that race motors have high current ignition systems, why not use a plug that probably won't fail mechanically?

Just a question from someone trying to catch up on what's new.
 

Comments between anecdotal experience and finite element analysis are welcome. 

[Jim Ratto]

the old 4 cam Carrera motors specified them.

[WhiteTrash]

What are surface gap plugs?

[Jim Ratto]

http://www.densoplugs.co.th/images/10l.jpg

[TexasTom]

I've used them on a couple high-compression, Ducati race engines (modern).
Capable of making a few extra horsepower, but if everything's not JUST right, they foul easily and cause headaches! Then it's off with the bodywork (again) to swap for a fresh pair.
They need serious current to get going ... a magneto would be good.

[mr horsepower]

They were used on 2stroke engines it has to do whit the 2 stroke oil that sticks om the plug so you need a higher current to clean burn them .
in a coldstart 2stroke the plug gets very wet but when heated up the oil vapors and the engine runs clean
but if you use normal plugs in a 2 s before the engine gets warm the plug is soaked and will fail .

gr henri