Mopar 318 Ignition upgrade

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l6hmus

l6hmus

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Hi,

I'm planning to upgrade my ignition system (spark plugs, spark plug wires, ignition coil, in future do a HEI conversion) on my Valiant with 318 (came from a 73 roadrunner).

First step is to change wires, plugs and coil.

For coil my local shop has this:
http://www.summitracing.com/int/parts/msd-8202

Only difference is that in this kit: http://www.summitracing.com/int/parts/msd-8203 the ballast resistor is included but this kit isn't in stock (has to be orderd).

Now does this mean that this coil doesn't work with the original resistor (4 pin https://www.jimsautoparts.com/P4529795.jpg) and I have to order the 8203 version?

Also if I plan to make HEI conversion maybe it's reasonable to look for some different coil, because in this page: http://www.designed2drive.com/ it says so:

A canister style coil requires from 1.0 to 1.5 ohms to survive without overheating.
But the MSD has resistance 0.700 ohm.

I have read some of the threads in this forum abuto the HEI but don't have a clear picture of what is a good recapi for this.

Kristjan.
 
I might be wrong but I think any GM vehicle in the bone yard that has HEI ignition would also have a compatible coil.
 
l6hmus said:
Hi,Now does this mean that this coil doesn't work with the original resistor (4 pin https://www.jimsautoparts.com/P4529795.jpg) and I have to order the 8203 version?
.
Click to expand...

The "4 pin" resistor is two resistors. One is just like the old style 2 pin "points" coil resistor, and that is ALSO just like (or close to) the newer 2 pin electronic resistor.

The second half of the 4 pin setup is to supply power to the OLDER "known as 5 pin" ECU boxes. MOST ECU boxes are no longer 5 pin. You cannot tell however by looking. Some 4 pin boxes have 5 physical pins. Frankly, I would just leave things alone until you do the HEI conversion

l6hmus said:
A canister style coil requires from 1.0 to 1.5 ohms to survive without overheating.
But the MSD has resistance 0.700 ohm..
Click to expand...

That statement depends on who made the coil and "what" it is. It is pretty much true ONLY of OEM coils.

Negating the HEI issue. There is "a couple of things'

Let's say you were using the MSD with "points," no electronic. What you would want to do is use whatever resistor the COIL MANUFACTURER says to use. "Pay attention." some of the older Mallory and Accel coils, what you did was ADD the new aftermarket resistor in series!!!! with the old existing OEM resistor.

With Mopar ECU boxes, this adds a SECOND issue. There is some coil combos that are not going to work with those boxes.......too much current.......without proper resistor. This gets into a whole can of worms esp with modern day chineseoated replacement parts

The HEI modules SEEM to be pretty tolerant because of internal circuitry in the module. I ran mine for two years using the factory Mopar coil and NO resistor. There is NO doubt it generates a much much hotter spark than did the old ECU /resistor setup.

Whether that blaster is a good choice for the HEI I have no idea.
 
Here is a crop out of page 8-121 of the 1973 shop manual. The "compensating side" feeds the coil, the "auxiliary (control unit side)" feeds the ECU. That is what was eliminated in the newer, "4 pin" ECU
 

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I bought one of the self contained chineseium HEI units from Skip White on Ebay. I have used these in the past and have run them up to 6K+ rpm with only one issue - the shaft seal started weeping allowing oil into the cap. Some guys claim they break up and pop anything over 4K rpm... I have yet to encounter this issue, I put one in this Duster after having used one from skip in a bracket car for 3 years before converting to MSD / pro billet unit due to the shaft seal leak I mentioned. MSD units are far better pieces but the HEI's will get it done for a driver.
 
Here is the shop manual specs for a 67 hemi. As you can see this is very similar. This was for a breaker points system, of course
 

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l6hmus said:
A canister style coil requires from 1.0 to 1.5 ohms to survive without overheating. But the MSD has resistance 0.700 ohm.
Click to expand...
The MSD ballast has a resistance of 0.7 or 0.8 ohms ONLY when it is COLD. When you start the system, then the resistance will rise into the 1.5 to 2 ohm range with 30 seconds to a minute. The MSD ballast will be fine to with a coil resistance of around 1.5 ohms. The original Chrysler ballast was 0.5 to 0.6 ohms COLD and worked fine with a coil resistance of 1.5 ohms. (Like Del listed above.)

Advance Auto and other box stores sometimes stock the Pertronix Flamethrower coils PN 40001 or 40011 that works fine with the MSD or original Chrysler ballast.
 
Hi,

Thanks for the reply!

As I undestand then the MSD will work fine just in case buy the correct one (with the ballast resistor).
But I might to as 67Dart273 said and leav it alone before I do the HEI conversion.

Kristjan.
 
A member here trailbeast sells a hei conversion that works very well, it will eliminate your ballast resistor, watch his video, I have this set up and couldn't be happier.
 
I agree with Trailbeast, do the HEI now rather than later. I complete the HEI on my son's 318 Valiant and picked up 4 MPG. (from 7 to 11). As soon as I can find some free time, I want to tune it a little better to see if I can squeeze a few more MPGs out of it.
 
I recommend the Pertronix E-core coil 60103 for use with an HEI setup for a couple of reasons. First, it has very low .32 ohm primary resistance and the HEI module has no problems dealing with it - without any ballast. That means that you can get more power to your plugs. Second, it has screw-on lugs that make it easy to connect other electrical accessories to the switched power.

http://www.summitracing.com/parts/pnx-60103/overview/
 
Powerflite said:
I recommend the Pertronix E-core coil 60103 for use with an HEI setup for a couple of reasons. First, it has very low .32 ohm primary resistance and the HEI module has no problems dealing with it - without any ballast. That means that you can get more power to your plugs. Second, it has screw-on lugs that make it easy to connect other electrical accessories to the switched power.

http://www.summitracing.com/parts/pnx-60103/overview/
Click to expand...

You can get the same coil without the Pertronics name on it for a lot less (like almost half that)
You pay extra for a logo printed on it.

Just sayin.
 
RedFish said:
I might be wrong but I think any GM vehicle in the bone yard that has HEI ignition would also have a compatible coil.
Click to expand...

Ditto. Don't fool w/ the older 4-pin HEI module. Take an 8-pin HEI module from a 85-95 GM V-8 truck (cars to 93). The module is within the "small cap" distributor. Also take the "external coil" and the cable that connects the two (simple plug-n-play). Snip the red (+12 V supply) and wht (tach) wires as long as you can. You can buy all above new from TrailBeast if you don't mind paying more. I like junkyards. I have even shed a tear for the poor GM vehicle as I molest it.

You can't easily use the GM coil w/ your current ignition system, due to the connector issue, so just stay w/ your current coil until ready to do it all. Sure, you could use the GM HEI module with any coil (preferably an e-core), but then you need custom wires and connectors, which is the headache.
 
BillGrissom said:
Ditto. Don't fool w/ the older 4-pin HEI module. Take an 8-pin HEI module from a 85-95 GM V-8 truck (cars to 93). The module is within the "small cap" distributor. Also take the "external coil" and the cable that connects the two (simple plug-n-play). Snip the red (+12 V supply) and wht (tach) wires as long as you can. You can buy all above new from TrailBeast if you don't mind paying more. I like junkyards. I have even shed a tear for the poor GM vehicle as I molest it.

You can't easily use the GM coil w/ your current ignition system, due to the connector issue, so just stay w/ your current coil until ready to do it all. Sure, you could use the GM HEI module with any coil (preferably an e-core), but then you need custom wires and connectors, which is the headache.
Click to expand...

Curious. What's wrong with using the 4-pin HEI module?
I read about HEI until my eyes bled, and I don't recall reading the 8-pin was better. LOL
(I may have missed it)
Thanks
 
I switched over to a DynaMod 4-pin module and an MSD SS-blaster e-coil with good succes. Hooked it up behind a relay so it gets good power.

No more fumbling with resistors and matching coils or anything.

I still have most of the stock Mopar ignition system in the car 'as a backup' but the engine is running way better with the HEI module.
 
equium said:
Curious. What's wrong with using the 4-pin HEI module?
I read about HEI until my eyes bled, and I don't recall reading the 8-pin was better. LOL
(I may have missed it)
Thanks
Click to expand...

The 8 pin module advantages over the four.

1. It's not susceptible to low voltage death like the four.
2. The 8 uses waterproof connectors so no corrosion of the terminals.
3. The 8 pin has timing changing abilities and is compatible with most EFI systems.
4. Since it has timing changing abilities it can be used for forced induction systems.
 
BigBlockMopar said:
I switched over to a DynaMod 4-pin module and an MSD SS-blaster e-coil with good succes. Hooked it up behind a relay so it gets good power.

No more fumbling with resistors and matching coils or anything.

I still have most of the stock Mopar ignition system in the car 'as a backup' but the engine is running way better with the HEI module.
Click to expand...

I had my OEM stuff in the trunk for awhile also, till I ran across a guy with a Duster and a dead ignition system on the hiway one day.
I got him going and the next day he came over for an HEI kit swap. :D
 
The megasquirt site has much info on all GM HEI modules.

Add to TrailBeast's list - easy connections.
As mentioned, you take the GM cable that connects their coil to module and snap you are done there. You only need to apply 12 V ignition power to the red wire on the coil and ground the case of the HEI. You also need to add a dbl-bullet connector to the 2-pin pickup cable that you also wisely snipped off the GM engine, and 50% chance on getting the polarity right. If over-whelmed by the later, just buy TrailBeast kit.

TrailBeast, tread lightly with those stories of failed Mopar ECU's. You risk ticking off several members here who swear they are totally reliable and no "Chevy part" should touch a Mopar. Did Chevy or Mopar even make electrical stuff? I kind of recall, but they sold those divisions off long ago.
 
BillGrissom said:
The megasquirt site has much info on all GM HEI modules.

Add to TrailBeast's list - easy connections.
As mentioned, you take the GM cable that connects their coil to module and snap you are done there. You only need to apply 12 V ignition power to the red wire on the coil and ground the case of the HEI. You also need to add a dbl-bullet connector to the 2-pin pickup cable that you also wisely snipped off the GM engine, and 50% chance on getting the polarity right. If over-whelmed by the later, just buy TrailBeast kit.

TrailBeast, tread lightly with those stories of failed Mopar ECU's. You risk ticking off several members here who swear they are totally reliable and no "Chevy part" should touch a Mopar. Did Chevy or Mopar even make electrical stuff? I kind of recall, but they sold those divisions off long ago.
Click to expand...

I'm still catching up from the flood of kits I sold last time someone bitched. :D
Shipping two more kits tomorrow, and one more to deliver locally so that's 6 in the last few weeks.
Getting hard to keep up and do everything else I have going on at the same time.
 
I like easy upgrades and this one is about as easy as you can get. Totally worth it. The difference was subtle but many people said, "that engine sounds really good" after that. Drivability was better overall.

Due to my clumsy handling, I later 'upgraded' the coil connectors to NAPA 'pro' connectors as my clumsy handling broke the thinner connector wiring. No big deal, I like the larger connector wiring. I also added a relay to power the coil from the starter relay + post.
 
Dont even fool with the old oil filled canister coils with a capacitive ignition, E-coils are where its at. Crane PS91 has .430 primary resistance and you can mount them anywhere, upside down...
 
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