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Discussion Starter · #1 ·
Alec87CJ\'s Ignition Questions...

*Alec87CJ* Asked,
*I have a friend who just picked up a J truck with a 401 in it. It has points in it! What would be the easiest distributor to swap in, in order to have an electronic ignition?*

Depends what year the engine is. If the distributor drive gear, and lower distributor housing match the early Motorcraft distributors, (say, '79 Jeep anything with 304 or 360 CID AMC engine), and the oil pump drive are the same, then the entire upgrade is off the shelf. If you want to keep the factory quick connects, it will take some extra time to make the wiring harness, but it only adds about $30 to the cost of the project, and you can take any faulty components out and just snap new ones back in.
(See the thread you orignally posted your questions in for all of the parts needed an some pricing.)

*Alec87CJ* Asked,
*Also, I put the HEI in my 258. It already had an electronic ignition, but after hearing about how much everyone I loved theirs, I switched mine over too. I thought it was just me but the only "increase" in performance I saw was easier starting in the morning.*
*Should I just switch back and off load my HEI setup on someone else?*

What electronic ignition? Jeep went dumpster diving sometimes, and the systems they came up with didn't always do the deed, if you know what I mean...
If you had the Motorcraft distributor, all you needed was a cap and rotor upgrade, maybe a premium coil, plug wires and a set of advance springs. Around $80, total.
I'm not real familiar with that year of six banger, so I could be wrong...
I wouldn't call it 'unloading it', it's a great improvment for someone with points! I bet you could make them a heck of a deal on it if you decide to go back to what you had before...

*Alec87CJ* Asked,
*One more thing...there was mention of the HEI grouding out... would this explain why I see half a dozen burned up rotors a week?*
*(Not in my setup...just at work off of other people's GM's.)*

Of corse not YOUR jeep.... (Go look for black carbon & 'pencil' tracks on the rotor top, and red dust under the rotor, and get back to me...)

There are three things that almost all armatures do that should be taken care of...
1. Put the distributor drive gear on backwards. The chevy distributor has an odd number of teeth, so there is a front and a back to the gear. There is a dimple in the gear just below the gear teeth, and just above and offset to the roll pin hole. That dimple should line up with the rotor nose. If it doesn't, even when your engine is firing at the correct time, the rotor is 42 crank degrees away from the plug tower it's supposed to be firing.
That spark has to go somewhere, and with a cap full of ozone, and the distributor shaft closer than the plug terminal, it's either going to fire the plug tower it's closest to (detonation), or two plug towers (detonation), or to the distributor shaft (dead miss).
Combine that rotor phasing screw up with centrifugal advance movement of the rotor, and vacuum advance, and trigger errors, and cheap parts, and tolerances up to 20 times what they should be and it's a recipe for burned parts, and even engines hammered to death.

The AMC gears have an even number of teeth, (The gears used on the I-6 upgrades are AMC) so the most they will be mis-aligned is about 6 crank degrees.

(And nobody seems to know this stuff...)

2. Use those poor quality caps and rotors. Aluminum is a poor conductor of electricity compared to good brass terminals. The spark energy is going to take the path of least resistance, and to an aluminum plug terminal is not attractive to the spark.
Rotors are my pet peeve outside of aluminum terminals.
GM HEI rotors are notorious for being thin and easy for electrical charges to blow through. Aftermarket replacements form Mexico (or god knows where) are even less trustworthy. The spark energy is supposed to come down the center electrode, and if everything goes correctly, follow the rotor arm out to the plug terminals. It does just that a fare amount of the time.
It also finds the ozone, and the carbon particles in the rotor well, (rotor well, the hole the center spring fits into) and finds an easier path to go, just straight through to the distributor shaft and counter weights.
Ever see red dust inside those rotors? That's steel that has been VERY hot at one time.
The spark energy incinerates the iron in the steel, while trying to weld the weights and advance head to the distributor shaft.
(Anyone ever seen the red coating on a blast furnace? That is how hot the spark energy is.)

3. Not adjusting the rotor nose.
Most GM Style HEI rotors are generic at best. My favorite saying is 'One size fits nothing'. Those discount rotors are made to work with variations in distributor shafts, wear in distributor shafts, at least 50 different manufacturers of distributor caps, all slightly different, and no common quality control.
The good news is that the nose of most aftermarket GM HEI rotors can be bent our slightly to make them fit the cap. Just get a hold of it with a pair of needle nose pliers and bend it out a little, and put the cap on and turn the distributor gear. If it clears, bend it out a little more until it contacts one or more of the towers, then back it off until it just clears the inside of the towers.
(If you want to keep an old HEI around just to do this with, it makes a good tuning tool.)
That closes up the air gap between the rotor and the cap towers. I have seen gaps of 1/4" when the max. spec. is 0.015".
Just drop the box on end once, and the adjustment is shot, if it ever had one to begin with.

Does that answer your questions?
(You owe me one CJ Dave...)

When a fool and a wise man argue, Onlookers can't tell the difference...
 

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Re: Alec87CJ\'s Ignition Questions...

/wwwthreads_images/icons/smile.gif TeamRush, I think all of us are going to be looking at our ignition systems with a lot more critical eye now that we ALL KNOW!/wwwthreads_images/icons/wink.gif So many little things....adding up to one BIG thing...man, no wonder half the stuff running around doesn't get decent fuel mileage. I have opened GM HEI distributors which were RED inside from doing the arc thing./wwwthreads_images/icons/frown.gif Man, if I worked in an auto parts store now they'd think I was a genius. I already blew the very experienced and knowledgeable counter guys away with that Ford-on-Jeep retrofit as it was. The reaction was: WHaaaaaaat???/wwwthreads_images/icons/crazy.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
 
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Re: Alec87CJ\'s Ignition Questions...

Teamrush, I have been reading your advise and am very interested. I have an 83 CJ7 with the 6/258 that I have with the help of a friend recently rebuilt (4000 Miles ago). I was about to switch to the GM HEI. My question is how do I know what distributor I have? I know it is electric but which one? I have taken off the computer control Carter and replaced it with a 2 barrel Rochester with a new rebuild kit. When I am in park (TF999) the motor has a miss in it. I have adjusted the carb. to death tring to get it to run smooth. When in gear it seems to run fine. I have put new ceramic wires, new cap and rotor and set the timing numerous times attempting to get it right. I have saved the thread on adjusting the above and plan to try it as soon as the weather warms up. I also have been unable to find any vacuum leaks and have replaced numerous vacuum lines. My conclusion was maybe it is the ignition and the HEI would help. Now after ready your thread I am not so sure. I believe the coil to be the original. I am not a mechanic, but love to fool with Jeeps and have learned a lot doing as much as I can myself. Any advise would be greatly appreciated. Thanks
 

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Discussion Starter · #4 ·
Re: Alec87CJ\'s Ignition Questions...

I have written so may words my fingers are sore!
I should be doing this in page maker, and doing a book.
And to think, I spent years guarding this information like a jealous woman, and now I'm just giving it away...
You all owe me a beer each, you know that don't you.....

Too bad Off-Road.com won't just publish the article that's already done on AMC V-8's, and agree to publish the next one that's almost done on the 258 I-6.

Oh well, I'll get to them as quick as I can, so don't get upset...

Aaron.

When a fool and a wise man argue, Onlookers can't tell the difference...
 

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Re: Alec87CJ\'s Ignition Questions...

TeamRush,

I hope you dont mind, Ive enlightened some guys recently on the FSJ list, when the HEI subject came up I suggested searching this BBS for YOUR info on improving the Duraspark setup, I have thus far been ridiculed since the common thought is HEI is supererior...

hehe, better for me!, more AMC V8 duraspark setups in salvage yards for me, not to mention Mine will run better ....

and Ill get you a Beer when ever you want, I always have plenty of cheap but cold beer on hand..

OzarkJeep
NW Arkansas
 
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Re: Alec87CJ\'s Ignition Questions...

Teamrush

I've just spent the last couple of hours reading (and re-reading) your posts on this subject. Like so many others, I had become convinced that the HEI would solve all the problems on my 258, and I had planned on doing the swap. However, thanks to your wise words, I am putting those plans on hold.

Let us know when you complete your article on the I-6258. In the mean time, I'm going to start harassing Offroad.com with menacing email until they wise-up and publish your articles on the V-8 and I-6.

BTW...if your ever in the Portland (OR) area, I'll buy you all the beers you can drink.

Thanks again!

Go easy! You're talkin' to a greenhorn.
 

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Discussion Starter · #7 ·
Re: Alec87CJ\'s Ignition Questions...

Don't worry what the masses think, or say...
Until someone teaches them something, they are just chimps, swinging in the trees...
It's evolution, and maybe they will evolve, and maybe they won't... that's for nature to decide, not us...
The point is not to take any crap from them. Know what you know. If you don't have concrete, first had information, then you are just repeating what you have heard... Like a chimp imitating people.
I don't say 'I Heard' or 'Someone told me...'. Or 'I read in an advertisement'...
I give you factual, first hand reasons why things work like they do. I try to explain things so even the most non technical person can begin to see the way things work.
Notice I'm not getting ANY resistance from anybody anymore? No one with a brain can argue with facts for long.
I'm not much of a people person, but I know gears & wires!
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The most resistance and hate mail I get are from the Jacobs and DUI crowds. They seem hell bent on justifying why they spent $350 to $600 on a MSD wannabe or GM HEI that should have cost under a $100. I guess it still kind of smarts when they think about it.
MSD 6A is $131 this month in Summit catalog, and I see no point in the other stuff if you are not doing serous racing. But if you REALLY want it.... Be my guest....
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B.S. Warning from here down...
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Stop calling me High Grand Poo-Bah, and Sultan-O-Spark in the emails. It ain't funny on more. (I do kind of resemble Buda when I set naked with my legs crossed though... What a visual!!)
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You know something, out of all of these posts, no one, including CJ Dave, has asked what I have in my small block chevy powered jeep....?!?...
I won't run a GM style HEI in much of anything. I've seen their shortcomings, and I'm not willing to take the chance.

I have the small points style Delco distributor (fits better, no room in the back),
fitted with a Mopar style electronic pickup and reluctor (more accurate, and Stinger sold them as a kit with the advance plate),
a factory stock replacement vacuum advance,
some quick Mr. Gasket advance springs,
and sporting an MSD Cap-A-Dapt distributor cap base,
and a premium Ford brass terminal distributor cap,
a MSD phased rotor,
a Datsun full time 12 volt coil out of a mid 80's pickup (cool connector clip!),
and an MSD 6AL module.

I also have a GM HEI module mounted under the distributor housing to limp home on if something happens to the MSD module. The MSD has been in there 9 years, I don't know why I bother...

The only part of this system I can't walk into a discount auto parts store and buy off of the shelf is the MSD phased rotor.
I have extra tips for the rotor (MSD rotors have a screw holding the rotor tip in, so you can just change the tip, or in a pinch, just flip it over...), and what are the chances of a rotor going completely out?

Happy trails folks, Aaron.

When a fool and a wise man argue, Onlookers can't tell the difference...
 

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Discussion Starter · #8 ·
Re: Alec87CJ\'s Ignition Questions...

* Blk83CJ7* asked,

*I have an 83 CJ7 with the 6/258 that I rebuilt (4000 Miles ago).*
So far I follow you...

*I was about to switch to the GM HEI.*
I don't know why you would want to... The Motorcraft ignition can be made to out perform the GM HEI pretty easy.

*My question is how do I know what distributor I have? I know it is electric but which one?*
It's my understanding that Jeep used Motorcraft ignitions until '91. Take your distributor cap off and look at the rotor. Is it sort of a wedge shape? Or is it more round?
If it's wedge shape, sort of a triangle, it's a Motorcraft. Motorcraft rotors are distinct.

*I have taken off the computer control Carter and replaced it with a 2 barrel Rochester with a new rebuild kit. When I am in park (TF999) the motor has a miss in it.*
Did it have the miss with the other carb? If it did, you are chasing a ghost.
Does the computer control the ignition in any way? I have seen bad computers so what your are describing. (I don't think the ignition was controlled by the computer in '83)

*I have adjusted the carb. to death tring to get it to run smooth. When in gear it seems to run fine.*
At idle is where the most ported vacuum is going to be for the vacuum advance.
Try taking the vacuum advance line off of the distributor and plugging it. Does your miss go away?
Check and make sure your vacuum advance isn't leaking. Just suck on it and see if it holds vacuum.

*I have put new ceramic wires, new cap and rotor and set the timing numerous times attempting to get it right.*
Unless you got the distributor in one tooth off after the rebuild or something like that, or the vacuum advance canister is bad, I don't think it's the distributor. If you got the distributor in one tooth off, you will be able to set the timing correctly, but the rotor phasing will be off. If you combine that with centrifugal advance, vacuum advance, the rotor nose may be so far off of the tower it's supposed to be firing it's firing somewhere else. (Like to the next tower or the last tower.)
BTW, what the hell is a ceramic plug wire? Ceramic would break if you tried to bend it, so how can they claim ceramics? Doesn't that sound silly to you? I hope what ever you have, it is good enough to deliver the spark. I do wish we had just a little truth in advertising...

*I have saved the thread on adjusting the above and plan to try it as soon as the weather warms up.*
Sounds good.

*I also have been unable to find any vacuum leaks and have replaced numerous vacuum lines.*
Always a good idea on a 17 year old vehicle.

*My conclusion was maybe it is the ignition and the HEI would help.*
Here is a quick test... Get a second module and try it ($16.00). If that doesn't work, let me know and I'll tell you how to make a test harness to see if it's the wiring harness.

*Now after ready your thread I am not so sure.*
Still learning, that's good. Keep it up your entire life, and you will never say, 'I've seen it all!'

*I believe the coil to be the original.*
If you think that might be it, change it. It's 17 years old, and I'm sure it could use the rest.
Just get the stock Ford replacement Coil. If they have a $15 coil and a $25 dollar coil, and you can spare the $25, do it. Ford factory coils pretty well kick butt, so I really don't recommend the aftermarket coils.

*I am not a mechanic,*
If you rebuilt your own engine you are. If you are going to find this problem and kill it you are.

*but love to fool with Jeeps and have learned a lot doing as much as I can myself. Any advise would be greatly appreciated.*
I haven't 'Fooled' with anything since what's-her-face in high school.(she was fun, I kind of liked foolin with her, now, if I could only remember her name)

*Thanks*
You are welcome if it works, if not, I wasn't here....

Later, let me know how it turns out...

When a fool and a wise man argue, Onlookers can't tell the difference...
 
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