Surface Discharge Spark Plugs

[Engineer]

Has anybody else used them?

[pdtrewern]

What are they? How do they differ from the norm? :slap:

[volvotuning]

What are they? How do they differ from the norm? :slap:

Taken from NGK web site -

"Surface discharge spark plugs are used in many fishing boat applications, where alternate high-speed running and very low-speed trolling can cause fouling. The surface discharge plug helps keep the firing end clean under these extreme conditions for continued operation."

Adam.

[fireclown]

used them in 2 stroke go karts.

[Engineer]

used them in 2 stroke go karts.Were they Champion racing plugs?

[fireclown]

hi no they were ngk mainly used them because they didnt foul up as quick as normal plugs, they did have a big fat spark though. cant say how they would be in a high pressure engine.

[racer]

Weren't these the odd ball ones the rotary engined Mazdas used?

No idea if they are worth running in a T5. You tried them Adam?

[Engineer]

Thanks for the interest guys, originally posted to fish for some feedback on their usage in current turbo engines having only used Champion Racing surface discharge plugs to good effect in high compression B230 and B21 Turbo engines. One of my considerations was that the Champion and NGK racing SDP is not a resistor plug and would/could cause a problem with ECU interference.



The nearest resistor plug that comes close to the above and fits Volvo heads would appear to be a Brisk road or racing spec plug, unfortunately Brisk sparkplugs quality is suspect. Champion has recently developed a resistor SDP for Ducatti’s 999 Superbike which would support their advantages in high compression normally aspirated engines but these do not fit due to plug design.



I have now received feedback from someone who has experimented with SDP’s in high boost turbo engines and he has indicated their unsuitability due to spark blow out. Which I guess answers my original question unless anyone knows different?



Picture of Champion / NGK SDP.