HEI vs MSD

[elwood blues]

Since completing the Motorcraft 2100 carb swap, I have really noticed how bad my engine idles. So, I've been thinking, reading and pricing swapping in either an HEI (like a Davis Unified Ignition) or a MSD type upgraded ignition. And I have a few questions.

1. What is the main differences between the two?
2. Going with a DUI type HEI distributor, should I also upgrade the Ignition Control Module (ICM)?
3. Can I install just a MSD coil and ICM, and not a brand new distributor? Can I get away with just a new cap and rotor?
4. Pros and Cons of both?

Thanks in advance everyone

 

[CJ]

Short answer is MSD is an add-on, HEI is a swap. HEI is a very hot spark and MSD is multiple short sparks (laymens terms).

You can just add a MSD. You may get crossfire though.

What is your current distributor (year and type).

 

[elwood blues]

Factory stock distributor, couple year old NAPA cap, rotor, coil & ICM.

What I was looking at was this page
Application Guide
I was thinking about getting the full set-up, distributor, coil and ignition box.

 

[mylittlecj5]

I did a TeamRush conversion with a late '80s Waggy distributor upgrade. Then installed a MSD OffRoad ignition box and it worked really good. At least until the (used) MSD box failed. I installed a Summit Racing CDI box w/rev limiter on it now and am still trying to get it to run correctly.
If you do the TeamRush job, I used parts I had laying around for my '88 F-350 with a 460. Plug wires, Dist. cap (copper terminals) , rotor. Also added a MSD blaster II e-coil, same style as my F-350.

If you replace the Dizzy with an HEI, watch that the cam gear and the Dist. gear are made of the same material (hard or soft)! IF you mix and match materials, the harder one will eat the softer one up in short order (per JeepHammer).

 

[elwood blues]

~~~If you replace the Dizzy with an HEI, watch that the cam gear and the Dist. gear are made of the same material (hard or soft)! IF you mix and match materials, the harder one will eat the softer one up in short order (per JeepHammer).

Good info, I didn't know that. Thanks mylittlecj5

 

[coldwater]

The Jacobs I installed in my Jeep is one of the best things I have done to it. I swear it was like a new engine under the hood.

 

[elwood blues]

I know you have the ignition control module, but what did you do about your distributor?

 

[coldwater]

Completely stock dist. I installed the Jacobas mileage master pack and coil. Athought I should swap them out just because of age, I still have the same plugs in it for 12 years now. I pulled them to have a look back in the spring, and they still look nearly brand new. It starts instantly, runs smoothly, even when ice cold, pulls hard from any throttle possition and gear with no lag or hesitation. Seat of the pants torque and horess were way noticeable, and the fuel mileage went up considerably. If it were to give up tomorrow, I would buy a new one before I even thought about driving it again.

 

[elwood blues]

Alright, I'm going to do this. I have another question, I'm looking at the 6A $165.95



6AL with the rev limiter $197.95



and 6 offroad $239.95




So, which one should I go with? I get that the 6AL has a rev limiter, will I ever really need that? Will I ever really need the performance of the offroad, it's not going in a rock buggy. My CJ rarely gets offroad (stupid state of CT), and even if I get offroad, the rest of the darn thing is stock... Any opinions?

 

[coldwater]

Coil??

 

[elwood blues]

MSD Blaster 2F $40.95



Or Blaster High Vibration $45.95

 

[coldwater]

http://www.malloryperformance.com/P...&majID=534&minID=0&selection=3&minselection=5

This is more along the line of what I use. You can sort of see it on the far fender. Ignition and coil.

 

[elwood blues]

Mallory Hyfire 6 EZ $199.95 (kit includes coil)



That looks like a good deal to coldwater. Now I really don't know what I want.

 

[coldwater]

My being a complete moron about anything electronic, I have no idea of how mine works. I just fell to marketing strategy, and bought it because of an article I had read. I guess the "computer" reads the resistance at the plug when it starts to fire, and starts a spark, the more it reads the need, the harder and hotter it will throw fire to it, giving a pretty full if not complete burn which equals better power and mileage, and eliminates fouling, which is pretty much proven to me by my running the same plugs for 12 years. The coil throws some rediculous power number to the plugs through their own wires. I have some cracks in the wires and tried to swap them to Accel wires (IIRC) and burnt holes in them almost right away. There was also a little wire I had to splice in at the alternator, or the ignition would read tiny bits of power coming from the alternator after you turned the key off, as a need for spark and keep the engine running. You couldn't turn it off and would have to stall the engine out manually. I know this, because I forgot to install the little wire. SO..If you are going to get anything, I recommend the entire system. I think it's the best bang for the buck over all.

 

[BrockGrimes]

I swapped the cap, cap adapter, rotor, wires and coil for ford TFI parts, and use a GM 4 pin ignition module. It's hot hot hot and didn't cost me near the price of an MSD setup.

 

[CJ]

~~~ Jacobas mileage master pack and coil. ~~~

Looks like Jacobs was purchased by Accel... http://www.jacobselectronics.com/

 

[coldwater]

Looks like Jacobs was purchased by Accel... ACCEL :: Welcome!

Yeah it was sold to them a while back. Too bad, as Jacobs itself was not only a great innovator, but as a company, the customer service was incredible.

 

[kicknjeep]

I swapped the cap, cap adapter, rotor, wires and coil for ford TFI parts, and use a GM 4 pin ignition module. It's hot hot hot and didn't cost me near the price of an MSD setup.

yup me too......

 

[coldwater]

Mine.

 

[BrockGrimes]

yup me too......

I used an old CPU heatsink to mount mine, and artic silver between the module and heat sink.