pining,twin plugging,etc...

[Gary Derian]

Alain, I believe you are on track.  Two sparks means two flame fronts means
the fuel burns faster means you can start later and still get done in time
which reduces pressure while the piston is still going up.  Compact chambers
with 4 valves and a central spark plug will benefit little.  Large thin
chambers with a plug at the side (Chrysler and Porsche hemi) will benefit a
lot.

In order to make lots of power the engine must 1) flow a lot of air, 2) mix
the air with the correct amount of fuel, 2) compress it a lot, 3) burn it
fast, 4) expand it against a piston.  All of these things must be done well.
Dual plugs address only number 3.

Lots of turbulence also burns it fast.  Burning too fast is not good either,
the engine parts get hammered.

Gary Derian <gderian at cybergate.net>


>time to put some confusion out,first,it was pining who got done on the
>hemi motor,not the twin plug thing,second,it was the pinto motor who got
>the twin plug thing and it was destined to the street (even if it was
>basically a race thing),third,the second plug doesn't increase VE,it
>increase positive cylinder pressure (and decrease the negative one),it do
>so by decreasing the spark advance needed (so there's more pressure
>ATDC),hope this replace the clock on this topic (and it help somewhat).
>
>Alain
>