Here's an additional tidbit of GM HEI wisdom for you all: Let's say you have an XJ Jaguar, maybe a V12, sitting in front of you with a dead electronic ignition module. That module is $175 and up as a replacement Jaguar part. So let's say instead you remove that dead Jaguar (actually, Lucas) module and turn it upside down. You open it up and what do you think you find inside? Why, a GM HEI module that might cost $7 at Wally World.
440ROADRUNNER - I was thinking more along the lines of enhancing the coil... PLYM49 - Been there, done that...on both of my Jags...
That's cool. I absolutely live for those road-side repairs. Or should I say my car absolutely lives for those road side repairs.
I have a bubbas dizzy setup in my truck .Its open motor have been caught in the weather many times . module is put on the bottom of dizzy and have not had any problems .
I had the same problem with it when it was mine. I was chasing the wrong tail, though (fuel) until I replaced the module with the stockie Mopar one. Scott that looks killer, and it's good to see that the stripes I painted on the valve cover are still there. That was one of the first things I ever striped! - Joe
We have tryed a point system with the hei control module and got our info from a Corvair forum. Problem was they fire the coil on the contact close in lieu of the contact open signal which causes some phasing issues on some engines. However using their diagram it did work. Should work on any dist that can be turned etc to change timing??
I hope GMCBubba can answer this one. On the mopar hei conversion, what coil do you suggest using. I know there are special HEI coils but can I get away with using a standard 12 volt coil or is there an ohm rating that is preferred with the GM HEI? Commnets will be appreciated.
The HEI control module uses a currect limiting circuit set at 5.5 amps. It takes a .5 ( 1/2 ohm) coil to allow this curcuit to function and get proper amps. You can use a standard coil ( 1.5 ohm approx) with no problems, however you wont ever see maximum current flow. I usually use a accel ( .9 ohms) from summit or jegs etc.
Bubba I checked with ACCEL and they have a canister type coil rated at .7 ohms # 8145. I assume that's the one you were referring to or do you use some other design that is a remote coil? I assume the .7 ohm rating would be as efficient as the .9 ohm rating that you noted. Thanks again for all of your help.
great read! used that fix about 20 years ago out 4x4ing with some people. one of them had already done conversion and had spare parts to get us going when the guy i was riding with had a breakdown. i was really glad and surprised that the one guy that had 90% of his truck fixed with duct tape came through.
I am using GMCbubba's set up for my 52 Chrysler hemi. I'm using a later model dizzy with the Hot Heads intermediate shaft to make it fit. The question I have has to do with the wire going from the dizzy to the GM Hei control module. One wire is gray and the other brown with a white strip on it. Which goes to the G terminal of the module and which goes to the W terminal? Thanks.
At the risk of too simple an answer, one quick test will tell ya real quick. Assuming your dizzy is in correctly, timing set correctly, etc... hook it up and see. It will either A) fire right up or B) backfire thru the carb. That was my lesson learned on it when we initially did the roadside fix. For those betting at home, my first hookup backfired on me. Switched the wires and it fired right up.
I dont have a pickup in the building that matches your color code so cant help you there. On our units from NAPA we use a orange and black wire with the black wire going to small terminal ( G) on the module. The GM module needs to see the positive pulse first for correct timing, and reversal will retard timing etc. We use a scope to verify pulse before putting it on terminal "G"....first pulse has to be positive...
The Jalopy Journal
