twin plugging

[GMR911]

What parts are needed for installing a twin plug ignition, thanks jerry

[FstTarga]

I’m not an expert by any means but:

Cylinder heads machined for twin plugs
Valve covers that accommodate twin plugs
993/964 distributor
2 coils

Or
12 VW 1.8t coil on plugs and everything but the distributor above
Some kind of stand alone efi

[Trackrash]

Originally Posted by FstTarga

I’m not an expert by any means but:

Cylinder heads machined for twin plugs
Valve covers that accommodate twin plugs
993/964 distributor
2 coils

Or
12 VW 1.8t coil on plugs and everything but the distributor above
Some kind of stand alone efi

Plus two CDIs.

or https://www.pelicanparts.com/cgi-bin/ksearch/PEL_search_2016.cgi?command=DWsearch&description=dual+plug

[H-viken]

And spark plug wires

[snbush67]

And spark plugs.

[GMR911]

Thanks for the info. Any good sources to purchase a twin plug setup. Thanks Jerry

[Steve@Rennsport]

Originally Posted by GMR911

Thanks for the info. Any good sources to purchase a twin plug setup. Thanks Jerry

Hi Jerry,

Lost of options here; may I ask what car/engine this would be used on?

[GMR911]

78 row motor 98mm cylinders 10-1 cr,964 cams, ssi exhaust

[Steve@Rennsport]

Originally Posted by GMR911

78 row motor 98mm cylinders 10-1 cr,964 cams, ssi exhaust

CIS, carbs or EFI?

[GMR911]

CIS, sorry about that

[Tippy]

IMO, if you’re going through the exercise of twin-plugging, might as well put either a MAP driven CDI box or EFI to take advantage of the part throttle gains you get from 3D mapping ignition

[mreid]

Or go old school like I did when I built the 3.2ss twin plug for my 904.



Twin plug heads
12 plug distributor
Twin coils
Twin msd boxes

[fred cook]

1980 motor, 100mm pistons/cyls, 964 cams, large port Carrera twin plug heads, large port CIS air box, SSI exhausts and Electromotive XDi crank fire ignition. Why have to keep buying expensive distributor caps and rotors? The XDi system has infinitely adjustable timing and does away with the distributor completely. The compression on my engine is almost 11:1, timing is set at 8 degrees initial with 20 degrees added at 3000 rpms. Runs great on 91 octane pump gas!

[GMR911]

Fred, what make pistons and cylinders are you using, Slip in or machine in. Can you use 100mm with single plug. Like to stay with 91 octane, non ethanol fuel which is plentiful here. Not sure I want to twin plug yet.

[fred cook]

Originally Posted by GMR911

Fred, what make pistons and cylinders are you using, Slip in or machine in. Can you use 100mm with single plug. Like to stay with 91 octane, non ethanol fuel which is plentiful here. Not sure I want to twin plug yet.

I used Mahle 10.1:1 pistons with LN Engineering slip fit cylinders. Because of some machining having been done on the cylinder heads, the compression actually wound up being about 10.8:1 or maybe a bit higher. I don't think you can run the 100mm pistons on a single plug. You will pretty much have to go to twin plugs.

[rdimarco]

You can get a JE 100mm piston with a wedge dome for single plug through EBS. Not saying it's better than a twin plug.