Head porting...Modern standards

[fredy66]

I'm looking in to heads at the moment too and what i find intresting is that many of the machine shops and head porters have  4  5 heads to pick from.
and i have mailed some of the companies and what i get is pick one of the heads we have no recomends to what i 'm trying to do

It depends on engine size and what you want to do . This makes the difference in what head you need . But a lot of peaople have different experiense

Udo

pm

[Lee.C]

Twin-plug set-ups on an aircraft form part of two separate ignition systems (twin magnetos, two sets of plugs, etc) so that should one system fail, the other will allow the engine to run. Before you take off in a light aircraft with twin magnetos, you always carry out a 'mag drop' test: watch the engine rpm as you shut off first one and then the other magneto. If all is well, the engine rpm will drop slightly by exactly the same amount in each case, showing that both systems are working OK. The rpm drop is because fuel is being burnt less efficiently on just one plug...

On a car engine, twin plugs result in a cleaner burn, primarily allowing the engine to run more cam overlap without wasting fuel.

Thanks dude - I kinda thought that was the reason but I didn't say in case I was wrong  I have noticed that Light Aircraft have 2 "MAG" switches,

Is there any particular reason its never been used extensivly in road/race applications 
I know SOME cars/companies have used the idea ie Porsche 

[TexasTom]

I believe twin plugs are somewhat frowned upon in racing rule books, specifically those classes that demand 'production specifications'.
And the automakers most likely don't quite feel the need to complicate things further by adding another ignition system, although I can't imagine it hasn't been tried and done.
Anything goes in the UNLIMITED classes!
All things considered, there's probably another 10-20% power available in a properly and proficiently extorted twin plug system. You will simply be able to burn even more fuel. Excellent for any positive pressure application, especially ... look at Top Alcohol & Fuel.

I've always been interested in these setups ... anyone have a photo or two of the SPARK side configuration of a twin plug setup? Distributor & etc.?

[TexasTom]

Here we go ...

Now get Jeff or Clyde or K-Roc or ?? to put an extra hole in those combustion chambers and we're off to the races!
Just think of the extra fuel mileage too ...

Link to the source site:   http://www.awesomepowdercoat.com/twin_plug_ignition.html

The tricky thing is accessing the bottom plugs.

[Diederick/DVK]

cool project, can't wait to read about results.
i cannot help but wonder how a magneto off a V8 would look!

[ugly duckling]

did a few pair of the SCAT SPLIT PORT heads some 17 yrs ago when i was SCATS SLAVE . twin plug aircraft guys 10mm plugs. no pics sorry . twin plug AF,S stay tuned  .   UD .

[TexasTom]

Wow Jeff! ... talented machinist, head porter AND Mind Reader!

[Lee.C]

Cool info - I reakon its worth further investigation

Any more info/pic's