Alfa Romeo twinspark

[steveurq]

Q's from newbie...

Has any body used any MJ systems on the twinspark engine, I assume you would need two coil packs but would you need dual EDIS's or a single one?

I assume there are no alternatives but to use the ford 36 tooth wheel as tha Alfa uses 58 (I think)

Thanks for any help.

[geoffnipple]

If youve got 4 cylinders...i'd imagine you could use an EDIS8 system...

just a thought

.Al

[steveurq]

How does that differ from EDIS4, my knowledge is not that great (yet).
Also, are there any alternatives to the standard ford crank wheel? Probably not but worth asking.

[steveurq]

It seems to me that EDIS8 would not work on a 4 cyl engine as you will get 8 firing events per 360deg whereas I only want 4, could I not use EDIS4 and parallel connect two coil packs so that each of the 4 firing events triggers 4 individual coils, i.e. 2 per firing cylinder and 2 per wasted cylinder?

If this is the case will the EDIS 'drive' (impedance etc) two parrallel coil packs?

Thanks

[geoffnipple]

You probably could run two coil packs but i'm not that fantastic with electronics so'll leave that up to someone else! its also easier to pick up 4's...However I think it using the 8 could work...

In an 8 cyl 4stroke you get 4 sparks per 360 deg (each cylinder takes 720deg to do a full induction/compression/power/exhaust cycle).

In your 4cyl you need 2sparks per rev, however if you trick the EDIS8into thinking its running half as fast (by running the 36-1 tooth wheel from the cam, or using a 72-2 wheel on the crank), you will get 2 shots per 360deg..assuming the EDIS8 is a lost spark system like the 4 (i.e. fires two plugs at once, one cylinder at top of compression, the other top of exhaust), you only need connect the plugs in the right order and the 'lost' spark will go into the chamber you want lit too! you also get the advatage all the spark energy goes into one cylinder, as opposed to half of it being wasted...

...maybe anyone?

.Al

[geoffnipple]

'72-2 off the crank', blonde moment...forget that youll have to run it off the cam..

i guess the problem will be you'll have is to double the ignition advance, that'll probably be more than the edis8 was designed for.

.Al

[alfadriver]

Instead of trying to adpat a pair of coils with the basic 4 cyl approach, use a Ranger Twin Spark system- they were available in the early 90's as a 2.5l twin plug head. It does use a pair of coils, but the EDIS box is designed to work as a twin plug set up.