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Topic: Duraspark Module vs. GM HEI "Kidney Bean" (Read 2471 times) previous topic - next topic

Duraspark Module vs. GM HEI "Kidney Bean"

Has anyone converted to the GM "kidney bean" module with a Duraspark distributor?

I dropped in a "ready to run" distributor and I'm tired of crutching the faulty vacuum advance, that and to 5,000 RPM the dizzy adds 35ish degrees of mechanical advance timing instead of the 20 degrees added by the Duraspark distributor. The "ready to run" distributor already uses a GM style module (only needs wires from + and - side of coil) to run, so I figure I will wire the Duraspark dizzy to the HEI module (purple wire to the "G" terminal, the orange wire to the "W" terminal and the ground to the same ground as the module).

I know I "should" wire in the whole duraspark box, but I need to add a ballast resistor and that requires additional harness hacking, something I've kept to a minimum with my carb conversion.

What's you guys thoughts on the matter?

Thanks,
Drew

Duraspark Module vs. GM HEI "Kidney Bean"

Reply #1 –
Quote from: tbolt64;447616

I know I "should" wire in the whole duraspark box, but I need to add a ballast resistor and that requires additional harness hacking, something I've kept to a minimum with my carb conversion.

What's you guys thoughts on the matter?

Thanks,
Drew

I think it'd be nice if we knew what year your car is...

That said I'm using a Duraspark dist to trigger a MSD Street Fire unit on my Comet, vac advance is a bit much so it's disconnected and just using the mechanical advance...

Duraspark Module vs. GM HEI "Kidney Bean"

Reply #2 –
My car is an '84 V8 car (used to be TFI)...

Duraspark Module vs. GM HEI "Kidney Bean"

Reply #3 –
Quote from: tbolt64;447616
Has anyone converted to the GM "kidney bean" module with a Duraspark distributor?

I dropped in a "ready to run" distributor and I'm tired of crutching the faulty vacuum advance, that and to 5,000 RPM the dizzy adds 35ish degrees of mechanical advance timing instead of the 20 degrees added by the Duraspark distributor. The "ready to run" distributor already uses a GM style module (only needs wires from + and - side of coil) to run, so I figure I will wire the Duraspark dizzy to the HEI module (purple wire to the "G" terminal, the orange wire to the "W" terminal and the ground to the same ground as the module).

I know I "should" wire in the whole duraspark box, but I need to add a ballast resistor and that requires additional harness hacking, something I've kept to a minimum with my carb conversion.

What's you guys thoughts on the matter?

Thanks,
Drew
What does that "ready to run" distributor tell you to set the base timing to?
If it is close to zero, then the 35ish advance is in the ball park.
The duraspark distributor adds 20° on top of 10° base timing.
The duraspark II module retards the spark while cranking with 12v on the white wire with the ignition switch in start.

Duraspark Module vs. GM HEI "Kidney Bean"

Reply #4 –
I am aware of what the cranking retard does and I do not believe it's necessary when you have the low compression these motors carry the starter should be just fine.

Yes, the "ready to run" deal recommended setting total timing as opposed to initial, but with no initial advance the car won't get out of its own way and is really only happy at interstate and highway speeds and gets poor gas mileage. The duraspark distributor is certainly the way to go.

Duraspark Module vs. GM HEI "Kidney Bean"

Reply #5 –
I have gone to the hei with duraspark for my cfi to carb conversion. I tried a duraspark module, but if I ran no ballast wire to the e-coil it would over heat. When I did run ballast it didnt put out enough spark. I wanted to keep the tfi coil. With the hei I ran orange to G. When I had orange to W, it would trigger the coil way to late. But I've been having issues don't take my word on it yet.