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Speaking of GM HEI

669 views 6 replies 2 participants last post by  CJDave 
#1 ·
/wwwthreads_images/icons/wink.gif I just learned that Davis Unified Ignition has brought out a new one-piece GM type HEI for the AMC V8 engines. It uses all stock GM parts, and just needs one liddle 12V wire to run. Has the GM type cap. I was going to go ahead and graft a GM to my AMC, but for 350 bucks, I could be better off to buy it. Buy the time I did the machine work and bought the two distributors AND then all new insides and cap for my finished product, I wouldn't miss the 350 by all that much. /wwwthreads_images/icons/tongue.gif

CJDave
 
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#2 ·
I remember reading somewhere, Jeep Owner's Bible by Moses Ludel?, that a HEI system works better if it has a remotely located coil instead of one that's mounted on the cap. Ain't sure about this, though. Just thought I'd mention it and see what responses come back. Thanks for reading.........

Jim
 
G
#3 ·
I've only heard of one person who has purchased the DUI HEI for an AMC V8. From what I recall, he had some clearence issues but was able to get the thing to work with out much trouble. IfI was certain I could not easily make my own then I would buy it in a heart beat. Even for that price I think it is a deal.

I talked to DUI a few months back and they mentioned they were also making an HEI for the 258. I asked them what was different between theirs and a stock GM HEI. He told me they machined the base so it would fit in the Jeep inline 6's. I informed them that there was plenty of us running HEI in our 258's and all that is needed is a gear change. He didnt believe me. Maybe they arent starting with an inline 6 HEI. Oh well.

I'm still betting that salvage yard HEI for an AMC V8 can be done with out a whole lot of trouble. Unfortunately, I've never seen an AMC V8 distributor so I cant see whats involved. You would be amazed at some of the stuff that is being done in the Howell users group. Those guys are fabbing up computer controlled HEI with all kinds of parts.
New batmoon man.

Regards,

Larry 85CJ7,350TBI,T19
http://www.treadlightly.org
 
#4 ·
/wwwthreads_images/icons/tongue.gif There are a couple of problems that have popped up concerning the grafting of a GM HEI onto my AMC 304V8 stock distributor. One problem is clearance. I wanted to get the HEI down lower to gain some strength, but the intake and the power steering pump are too close. Making the unit taller with the heavy coil up top is a risk on the AMC stem which is not all that strong. It's do-able with using the GM shaft, reworking the lower end to go in the AMC, and then machining the top of the AMC and the bottom of the GM with a register to assure concentricity and alignment. The 350 isn't all that much considering what all is involved, and it must be perfect or it's useless. /wwwthreads_images/icons/frown.gif I have never heard that remote coil vs mounted coil thing before. It's impossible to evaluate that. The GMs seem to work pretty well.....well enough to blow right through the rotor when you let the plugs and wires get too bad./wwwthreads_images/icons/wink.gif

CJDave
 
G
#5 ·
Earlier versions of the HEI had external mount coils. I just did it to my 258.
P/Ns' are Borg Warner:
Cap - C187P
Rotor - D158P
You can check at the parts store, the 1975 Chevy 292 had an external coil, mayby the V8s' did too. I also heard you can get a Ford adaptor to make it work, but never got more info in it.



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Randy Joyner
 
#6 ·
Well, I referred to the Jeep Owner's Bible and I didn't recall correctly about what was written there. Ludel mentions on pg. 288 in the section concerning performance up grades for the Chevy 2.8L V-6 that Chevy Performance people recommend eliminating the separate coil for racing purposes. Now I don't believe I would EVER want to race my 1986 stock XJ. (although I know it would blow the doors off an original VW Beetle--ha ha!)

I suppose there are some advantages to a HEI w/separate coil, one being clearance. My distributor is mounted behind and under the air cleaner and the coil is above the passenger side valve cover, towards the fire wall. Both put of the way of road water spray. I know that some GM engines, like the ones in Chevettes, the distributor is mounted forward on the driver's side and is very prone to getting wet. A friend of mine had an 81 to get around in and always was out in the rain, spraying WD-40 on his distributor on the side of the road. He finally bought a new Cherokee.

Another problem with the coil mounted in the cap might be heat build up but this might not be a major concern, though. Air moving thru the engine compartment would be able to cool the coil better if it was separate from the cap.

 
#7 ·
/wwwthreads_images/icons/tongue.gif By going to an external coil, you reduce the overhung weight of the distributor which; since it is quite a bit off vertical; is of concern in a real hard bump. The AMC V8 doesn't have much diameter at the entrance hole for a beefy stem, and it IS a concern to me....that would solve it./wwwthreads_images/icons/smile.gif

CJDave
 
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