DIY TECH TIP: MOPAR Electronic Ignition modified to accept CHEVY HEI Control Module

Useing your factory mopar electronic ignition distributor with a home made aluminum heat sink plate with heat sink paste and a GM 4 prong HEI ignition control module aka ICM

[@Jovan_of_Suffering]

Here from FB thread on a Dodge page. Thanks! Will be trying this soon!

[@cmintsurfer]

It may take a couple of replays to absorb all of this. I understand the need to have reliable transportation to get to work. Good instructional video.

[@BlownBudgetGarage]

CPU thermal paste is the perfect compound for mating an hei to a heat sink. I did the same thing when I converted over to it, I just happened to have some because I also picked up building computers. I didn’t make my aluminum heat sink quite as large as yours, but that’s only because of where I placed mine. Nicely done!

[@MoparMan-ff8fb]

thats cool . Yeah the heat sink plate is a little over kill but I figured under hood heat would be a heat issue especially during the hot missouri summer months to really keep it cool . also I dont know if you know this but if you take one of those 4 prong ICM to a parts store make sure they run the test on the module 3-5 times . once or twice is not enough . if it is a bad ICM or is starting to go bad or partially malfunctioning and you only test it a couple of time it may test good but once it warms up it will quit working so have them test it 3-5 times to see if it warms up on the bottom to see of it tests good or doesnt pass the test . I learned the hard way .

[@79tazman]

I use dielectric grease on the back of mine but I have mine mounted to a old computer heat sink it works great and keeps the module cool I thought about using thermal paste but they don't use it on cars from the factory and say to use dielectric grease on the back of it so that's what I use the heat sink keeps it real cool and the grease keeps it away from the moisture

[@MoparMan-ff8fb]

@@79tazman the paste does both keeps moisture out and helps pull the heat away from the module

[@The13thSword]

I wouldn't recommend using CPU thermal paste. While it does initially offer superior heat transfer qualities (about 16 to 17 times better than silicone grease), CPU thermal paste *will* dry out on you in a few years time, reducing it's heat transfer abilities considerably. It's standard preventative maintenance on computers to remove the old thermal paste and apply fresh paste every 2-3 years. Silicone grease doesn't dry out like that over time. I have never seen any recommendation in any repair manual for GM vehicles that the modules silicone grease should be renewed at any given time frame. No stated maintenance schedule for that at all. Also, while dielectric grease is a silicone grease, it is *not* the same in properties as a silicone grease made to be used for heat sinks. The latter has a metallic content for much better heat transfer. "Regular" dielectric grease is usually only a silicone oil with a silica paste for thickener; no metallic content at all. It is only intended to be used as an insulator and/or protector for electrical connections, to prevent arcing & especially corrosion, & to prevent spark plug wire boots from fusing to the the spark plugs. Yes regular dielectric grease will work for this, but it's just not as good as transferring heat as silicone grease heat sink grease or compound. Since excessive heat kills modules, it makes more sense to use the better stuff. I state this from experience in using both on this type of HEI Module conversion. In fact, the CPU paste dried out on me after a few years & became so ineffective for heat transfer, it cooked the module. Module was a very good quality one too, Standard LX-301. I've personally seen & heard of HEI modules using the standard silicone grease lasting for decades. Second biggest killer of modules is bad grounding. I always run a ground tab from the bolt hole in the module nearest the "B" & "C" terminals, using at least 14 gauge wire, to a clean & solid frame, engine or body ground.

[@stuckinmygarage6220]

The mounting looks REALLY solid. The bolts are grounding to your fender, so no really need the extra wire to it. BTW, I would suggest another location in case of water splashing? Thanks for the video.

[@moparnut6286]

Pretty cool deal.... I cringe at GM so I'd try using a ford TFI module just to keep it in the mopar family with its large heat sink that comes on some cougars 80s that mounts to the fender......and a good free soruce for heat sinks are old computers. But I still run my regular mopar 4 pin and just keep going....the one thing I do want is a distributor with a larger cap for less chance of cross fire! The good old ribbed mopar style caps seem to be all gone and can't find one any more. Keep up the good content man.

[@MoparMan-ff8fb]

the down side to the big bulky GM distributor cap and rotor is the space it takes up and taking the coil off the top and GM/chevy rotors have a habit of burning a hole the size of a thin sewing needle through the rotor and arcing to the distributor and causing mis fires or buring up the ICM and or coil . I just stick with the factory distributor and ever 500 to 1000 miles I scrap the end of the contact of the rotor and the contacts inside the distributor cap to make a better connection

[@moparnut6286]

@@MoparMan-ff8fb true if using a GM style HEI distributor but there are aftermarket ones that use the larger cap like the Ford male style and you mount everthing externally I figure as long as I'm modding it I'll get it the way I want. But I've been happy with the old mopar distributor and found no need to change it yet......my buddy has one of those HEI distributors on his 90s roller cam 351w in a 79 f250 that I installed I'm waiting to see the cheap distributor blow!😁

[@blakenorman4822]

You grounded that aluminum heat plate to the body and battery from the mounting bolts? Ive got a 87 slant 6 in a 47 dodge with a new carb and it just misses a little bit, just doesn't quite run completely smooth, bought a new vacuum advance distributor, going to try this with the distributor see if it smooths out my engine, thanks for video

[@wadehearn6230]

I converted my 74 Dodge D-200 a few years ago and it worked well. Do you know or have handy which wire goes to which terminal from the reluctor to the HEI module. It seems I changed mine back and forth, but it would still run. Mine has gotten to the point that I have to spin the engine up and when I release the key to the run position it kicks off. It acts like there is a resistor in line, but I took it out (one of the reasons do this conversion). I have swapped the wires again a few times with not improvements. I guess it could be the hei is failing. I mounted mine to the firewall next to the brake booster. Planning to move it as it gets wet sometimes which doesn't help. I added a relay to mine give it 12V when starting. I had the same old opportunity most has had with the ignition switch. I lot of the wiring on these vehicles are a challenge sometimes. The last time I has an opportunity with wiring, i just about rewired the dash. The amp gauge was fried which didn't help the charging and it always pegged my aftermarket amp gauge most of the time. Took all that out added a volt meter, works like a charm. I don't guess you get much road water slinging up on the module during rainy days? Again, nice job. Thanks in advance for your input.

[@MoparMan-ff8fb]

the Orange wire coming out of the pickup coil in the distributor goes to the W on the 4 prong ICM module. black wire from pickup coil goes to the G on the ICM

[@wadehearn6230]

@@MoparMan-ff8fb Thanks big guy.

[@CRUZER1800]

Back in the 60's, common practice was to change the plugs and points every 10K miles to maintain good performance. You could go much longer if you wanted to fiddle with filing the points and or replacing the condenser and sand blasting the plugs. Russ

[@MoparMan-ff8fb]

yep I've done that on my points in my 65 dart . I run NGK's now and no fouled plugs . ZFR5N in my mopar engines . they have longer electrode electrode tower . their made for 2002 + jeep cherokee 4.0 liter plus their made for up to 0.045 gap hei and inside all NGK's they have a sold rod instead of a section of rod and a small spring for electricity to travel through

[@CRUZER1800]

@@MoparMan-ff8fb Seem like modern plugs are almost bullet proof. My 98 Caddy which I have had for almost 20 yrs is still running the original plugs with almost 100K miles.... still runs like a top. Russ

[@79tazman]

I just got a old champion spark plug machine for Christmas it has a meter to test the plug and you hook air compressor to it and it sand blasts the end of the plug it's awesome I love old auto mechanics equipment the thing even works it came with a big fat champion spark plug in it the kind you can replace the porcelain anyway I found one on ebay that's the same thing as mine here is a link of it www.ebay.ca/itm/Vintage-Series-600-Champion-Spark-Plug-Cleaner-Tester-Restored/203234736634?hash=item2f51bbf9fa:g:FIIAAOSwMFhf7jW7

[@MoparMan-ff8fb]

@@79tazman I'd like to find in good working order a mechanics ohms/ rpm meter box for checking points ect

[@longbed7204]

What 4 pin module is that

[@MoparMan-ff8fb]

chevy / GMC 70s model

[@mansonmydog]

I noticed your comment on BTP about someone N. of Chadwick who had antique cars. Would you have any contact info for me?

[@MoparMan-ff8fb]

I don't have his number but my friend might . it's better to go there he is very resonable on prices cash only . but the only thing is when I say the vehicles are packed in like puzzle pieces they are . some times you have to walk sideways or walk across vehicles to get to a certain vehicle . we spent most of the day getting to and getting a 8-3/4 out of a 70s dart . it had factory 3:23 gears with sure grip . I think our buddy paid 150-250 for it . but we had to take it apart to carry it out of the small hauler it was in . it's best to go during the spring or fall when biting bugs and snakes are not out . how far way do you live ?

[@mansonmydog]

@@MoparMan-ff8fb I live in Independence. When I was younger I used to ride in Chadwick, when you mentioned that it caught my attention. Being I'm so far away I'd like an address or phone# if possible.

[@MoparMan-ff8fb]

@@mansonmydog give me a couple of days to get ahold of my buddy . I don't know the address or number I just know how to get there .

[@thecentralscrutinizer5105]

My Gawd man.... Go get some braided wire loom and hide them uglyass, crappily wrapped, home-made harness' couz... *DANG!!!* _"It takes away from ze Now darhling"_ ~Edna Mould I'm w/ Edna, It detracts, degrades that beautiful heat sink you made out of the embossed steel plate _"Wrap That Rascal"_ ~Whirled Peas