Piston plug?

[Einar Sjaavik]

>On the topic of spark plugs... has anyone seen the info on the new Saab 
>plug. Engineers replaced the standard plug with a single isolated 
>electrode then built up a special piston with a peak in the middle. The 
>peak acts as the ground, causing a spark to jump across the combustion 
>chamber. By changing timing they can change the effective plug gap as 
>well. Sounds like the best plug to date.

How do they go about changing the timing _without_ changing the gap?
I would imagine 40 degrees of advance would need a pretty hefty voltage
to make the spark jump over to the piston.

And what happens when the time is up for a plug change?
"OK. That'll be four plugs, four pistons, and then a full
 engine teardown to change them. 'Have your wallet ready?"

Was this invented about 16 days ago :-)


--
einarp at ade.no  ( Maserati Biturbo Spyder )