GM four pin Module

[valiantboy_66]

Hey, what is the deal with using a GM four pin module with the slants electronic distributer? What are the advantages? Would or could I use a GM external mount HEI coil for more KV then?

[mopar_nocar]

check out this link:

http://www.slantsix.org/forum/viewtopic.php?p=92166

i would use some other aftermarket coil.

sb

[slantvaliant]

Dan's write-up explains it well.
HEI works very well, with no real vices in this application.
Getting rid of the ballast resistor is a minor advantage, but it doesn't hurt. It does mean one less spare to carry. You DO carry a spare, don't you?
For me, the choice was made by availability. I found the HEI parts cheap, and found them first.
I had already picked up an electronic distributor and connectors from a car that was missing the ECU. If it had had a complete Mopar system, that's what I'd have today.
A breakroom conversation on the subject netted me the four-pin HEI module from a Corvette (As far as I know, it's the same as any other HEI from the same era.) I grabbed a spare module and some screws from a junkyard Caddy. The Caddy module was used for the first setup, and lasted 30 seconds before roasting itself. The "Corvette" module has been running over a year.
The only thing I had to buy was the skinny female spade terminal.
I am running a leftover Accel Supercoil, Autolite 985's, and nothing else special.

_________________
"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss



1964 Valiant V200, 225/904 PB
BBS, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

[dusty7t4]

anyone try this set-up with higher compression?

-dave

_________________
what part of "illegal" is so confusing???

[cavisco]

The Mopar system uses the positive temperature coefficient of the ballast resistor to regulate the primary coil current with changes in duty cycle (engine rpm). A simple, relatively reliable system for most daily drivers. The disadvantage with the ballast resistor is the slow response time of the resistor resulting in the field of the coil not being fully charged during sudden acceleration ie, a spark that may not be as hot as is possible with more modern systems. The GM HEI module is typically based upon a Motorola (now Freescale) MC3334 IC or equivalent. The MC3334 regulates coil current using an internal variable voltage reference. This internal variable voltage reference is able to respond much faster to changes in duty cycle resulting in a much hotter spark durring times of sudden acceleration and less destructive heating to the coil during low rpm operation. The MC3334 also imposes a 1 msec off time to ensure complete discharge of the coil field during a spark event. At very high rpms coil current is limited due to the slope of the coil's primary charging ramp time which is determined by VBatt and the primary impedance of the coil itself. Some good OEM coils are the Ford "E" core coils and the remote GM coil which is also an "E" core design. The MSD Blaster line of aftermarket coils are also very good coils. Don't be fooled by claims of HIGH VOLTAGE from the perveyors of coils. The voltage developed by the coil will only be as high as the break-over voltage of the plug firing, typically only a few thousand volts. When shopping for coils it is important to look for a coil with a high Joules rating and match the rpm range to your needs. If the coil manufacturer does not publish the joules rating of the coil, walk away and buy somewhere else. Don't use a race only coil on the street. It will just overheat and fail.

[vynn3]

Dan's instructions told me "how".

This told me "why".

Thanks!

VM

[valiantboy_66]

Dudes you rock!
You just Chevrolized my Moparitis now I just have to find a way to hide it.

[cavisco]

Don't forget, the Mopar Electronic ignition was a giant leap forward when first introduced, replacing points with a solid state transistor switch. Mother Mopar was always breaking new ground with excellent engineering in those days.

[Ice Titan]

Wow. Most informative new thing I've read on here in a while.

[slantvaliant]

If you have trouble putting GM parts in your Mopar, just think of them as I do:

Spoils of War.

My Valiant is still on the road after over 40 years, and the ignition donors are not.

_________________
"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss



1964 Valiant V200, 225/904 PB
BBS, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

[Alexandre Garcia]

Before worrying yourselves about chevrolizing your mopar, check brasilian built mopars: the tranny is not a new process, 230 or 833, but a clark 260 series, 3 or 4 spd, and the bolt pattern in the bellhousing is the same one as chevys, so putting a Muncie i.eg. behind a 318 here is easy, since they match, and teh rear end is a local copy of the chevy 10 bolts, c clips and all the rest. Now about a ignition module, what is it when compared to a rear end or a tranny??Just loved this conversion, no more leaking module and burning ballast on the inner fender.