Wheel on dizzy instead of crank

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DuffMan
MS/Extra Newbie
Posts: 3
Joined: Tue Jun 22, 2004 2:44 pm

Wheel on dizzy instead of crank

Post by DuffMan »

Tell me if I'm crazy or not: My idea is to use a smaller sized 36-1 wheel in place of a stock distributer. Now obviously the dizzy rotates half for every crank rotation, so you would need a 72-2 wheel, but since those aren't as easily available, I was thinking of using an EDIS-8 on a 4 cyl engine. If I'm thinking about it right, this would work, and you would no longer have waste spark. Right? The edis would see half the rpms, and advance values would need ti be halved.
renns
Site Admin
Posts: 1051
Joined: Fri Apr 02, 2004 6:12 pm
Location: Ontario, Canada

Post by renns »

I'm running a 72-2 wheel setup on my rotary with twin EDIS4 modules. It's been working great! A fellow forum member tried it first, and then sent me a wheel to try as well. He used 72-tooth gearstock material, bored for press fit onto the dizzy shaft. The outer diameter (~ 1.5") was such that the stock VR pickups in the dizzy housing were used to trigger the EDIS modules.

As for your EDIS8 concept, that should work for COP, although others have used the twin EDIS4 method instead. The issues of advance angle and incorrect rpm would need to be addressed, but you've picked up on that already. One benefit would be the crank speed limit would be effectively doubled, so you should be able to spark a 4cyl way up to 16k rpm or so with this setup.

Roger.
1979 Mazda RX-7, running MSnSExtra hi-res 09c for fuel and spark control on a turbocharged, intercooled, and (of course!) injected 13B rotary.
DuffMan
MS/Extra Newbie
Posts: 3
Joined: Tue Jun 22, 2004 2:44 pm

Post by DuffMan »

Do you know where he got the 72-tooth gearstock material?
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