Wagoneer AMC360 HEI Ignition

Dec 12, 2009 17 Replies

Does anyone have any opinions or thoughts on the advantages/ disadvantages of converting an AMC360 ignition from standard distributor to HEI? Are there different HEI installations that apply to the AMC360?



I had heard that the HEI distributor was more moisture-resistant than OEM installed distributor.



Thanks!



olts.http://www.summitracing.com/search/make/AMERICAN-MOTORS/engine-size/5.=..

Thanks. What is the difference, if any, between HEI and MSD?

Are you having problems in this area? If not, I wouldn't bother. Afaik, if that's your '87 it would already have electronic ignition, right? If the vehicle is not giving problems then don't fix things that ain't broke. If you're concerned about moisture then a new set of plug wires should address that.

Earle

volts.http://www.summitracing.com/search/make/AMERICAN-MOTORS/engine-size/5...

Thanks. What is the difference, if any, between HEI and MSD?

join the

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to research options there.

There are other modifications that you can do if you don't want the HEI distributor. BUT all those that have HEI distributors seem to love it! ;-) I think that

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was one of the first to have a drop-in HEI for the AMC 360 engines although I can not easily find it on his newer website. :-(

No, no problems, just looking to possibly enhance a weak point with this engine by improving the ignition system from stock.

Thank you very much, I will look into this, as I would like a simple conversion if possible.

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Thanks, Bill--I didn't realize that MSD was a brand, but they certainly do seem to have some good equipment to replace the old weaker coils, etc.

Thank you very much, I will look into this, as I would like a simple conversion if possible.

No, no problems, just looking to possibly enhance a weak point with this engine by improving the ignition system from stock.

I have to agree with Earl on this one. If it ain't broke, don't fix it. I dropped an MSD box in my Jeep and I didn't really notice much of a difference. I'm sure there was "some" performance gain, but nothing worth writing home about.

.

All things considered, I think you're right. There is nothing wrong with the starting or running of the engine, so probably best not to fool with it. It idles a little rough, but that may or may not even be ignition related, but a carburetor issue. The carburetor was recently rebuilt, but not really tuned, and I may be better off focusing on that instead.

Thanks for the advice.

Randall:

Here are two article that will explain the AMC 360 ignition and some things you can do:

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That being said, it is possible to get a lot of this benefit with upgraded drop-in components (see below). I was pleased with the results- idled better and seemed more responsive, although a totally subjective determination. The only problem is that the new plug wires are too fat for the Grand Wagoneer wire guides (don't force them - they will break) so you have to use the MSD separators listed below.

  1. ACCEL 140207 - ACCEL OE Replacement Ford Dura-Spark 45,000 V Racing Coil
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  2. MSD Ignition 8414 - MSD Cap-A-Dapt for Ford V8
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  3. MSD Ignition 35859 - MSD 8.5mm Super Conductor Spark Plug Wire Set
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  4. PLATINUM POWER SPARK PLUGS, gap to .44
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  5. SPARK GUARD INSULATING GEL
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  6. MSD Ignition 8845 - MSD Wire Separators
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Thanks very much, I will examine the links and the components and consider going this route.

I'm noticing right away that there is no actual replacement of the distributor, which I assume to be due to the fact that it all really happens in the cap and coil, along with the improved wires...?

--snip--

I'm noticing right away that there is no actual replacement of the distributor, which I assume to be due to the fact that it all really happens in the cap and coil, along with the improved wires...?

Randall:

You are correct- the distributor itself stays the same. The more knowledgeable Jeep and racing people here can, no doubt, explain more fully, but the intent is to present a more reliable, hotter spark to the combustion chamber.

The things that would reduce reliability (plug doesn't "spark" when desired) are these:

crossfires misfires

The things that would affect energy or "hotness" of the spark (not _plug_ hotness) would be the relationship between coil voltage and spark gap, and sometimes wire resistance.

So the "fixes" are designed to:

  1. Reduce crossfires and misfires by improving the insulation of the components- better wires, wider distributor cap, taller rotor and improving the electrical connections overall (attention to making sure that all electrical connections are making optimal contact, insulated, etc.).

  1. Get more spark energy to the plug: lower resistance wires, higher voltage coil, and a wider gap. The factory gap for the GW AMC 360 is .035, but increasing this to .044 was recommended based on the gaps used in similar Ford systems (the stock GW distributor is a Ford Motorcraft). You could try a further increase to .054, but this runs the risk of misfires at higher RPM or as the plugs age, so .044 seemed to be a good compromise. Plus the back plugs are really hard to access, so swapping plugs in and out is low on my list.

  2. Some of the more exotic improvements seemed to me to make sense only in the context of racing applications where high RPMs come into play, so I didn't see much benefit in changing the centrifugal advance springs.

  1. All of this is easily done, looks nice, and is reversible to the factory configuration without cutting wires or fabricating brackets or changing mounting positions or anything else.

  2. Changing out the stock Motorcraft distributor itself seemed to me to be a _very_ low bang-for-the-buck modification, and was not recommended by Gary Boyd in his lucid and thorough analysis.

This is a very good explanation and a good suggestion for a substantial probability of improvement with really very little effort. Many thanks!

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