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John_Strenk 09-10-2005 11:13 PM

Re: TFI and HEI what\'s the difference?
A side from the fact that the MSD is a capasitive discharge device I also think the multiple spark at low RPM is pretty neat.

Would there be any benifit to getting just 1 or 2 more extra spark per firing out of a Duraspark or HEI module a RPMs up to 2500 RPM. ??

I'm thinking of a Voltage comparitor for sensing the pickup and a couple of a 555 timer (556?)just to get 2 sparks out of a coil at each firing.

It looks like all you would have to do is pulse the Orange wire on the DuraSpark to fire the ignition module just like the ECU does on the 82 and later Jeeps.

The down fall of course is how fast you could saturate the coil each time. With a CD system you don't have to worry but with a coil it's slower. 2500 RPM would be like 5000 RPM in this case.

As long as you testing ignition modules why not add in Chysler? They have one that is as easy as an HEI or DuraSpark. Just 4 wires


OlllllllOCJ 09-10-2005 11:15 PM

Re: TFI and HEI what\'s the difference?
If you are a cheep guy, use the factory DuraSpark...
If you are adventuresome or experimental type, use the HEI,
If you want the best in your given RPM range, use MSD.

I personally don't care what anyone uses... but I don't want to hear the sob stories and complaints later...

[/ QUOTE ]

Getting close.....

If you are a cheap (or cheep) guy use the HEI module with a TFI coil and the Ford larger Cap/Rotor/8mm Plug Wires. Best bang for the buck! Period. You also get the benefit of common parts that will be available at any parts store.

If you have a pile of Dura Spark modules (like I do)... Just use them... Who cares if you burn them up... They become "Stealth HEI" modules.

If you are the adventuresome or experimental type (with a larger budget then most of us), Go with the same parts that the Drag Racer and NACAR teams use. Actually some use Mallory Ignitions... But many use MSD. There's no question in my mind that a CD ignition works better but I can buy a new set of gears or half a set of tires or save a little more for that front locker that would be so much more fun.

I personally don't care what anyone uses either. But why in the world would they spend too much for an ignition system for a Jeep based on how wonderful it works in a RACE CAR!!!

All of these parts may have some short comings.... but they were built into millions of vehicals.... making them very easy to find.... and they are very reliable for a daily driver or weekend warrior Jeep.

MSD gives you a kickback? Or you just have some strange fixation?


John_Strenk 09-11-2005 06:30 AM

Re: TFI and HEI what\'s the difference?
MSD actually works and is [i]relitivly[/i} cheap compaired to what you can spend on a Jeep for an ignition system. Actually you can spen a lot more on a MSD but I'm to cheap to even explore the difference right now.

Look at the price of a Jacob'$ Computerized ignition that actually compute$ what you need for your next $park. And then look at the price of a DUI.

I've used MSD in all my racing application. But someone else was paying for it.

Maybe the home built, modified GM HEI distributor should be given a shorter acronym like DIY.

Junk Yard Genius 09-11-2005 10:37 AM

Re: TFI and HEI what\'s the difference?

OK, now you have crossed the line Dale.


MSD gives you a kickback? Or you just have some strange fixation?

[/ QUOTE ]

No, I don't get a kickback, or anything from MSD.
(Other than a quality product at a very reasonable price)

The question was, What is the *Best* ignition for the money.
That would be MSD 6 series modules.
DUI, Jacobs, ect. are all much more expensive and don't do anything more (most do less) for your vehicle.

Although now that MSD's patent has run out on the original 6 series module design, you can purchase rip-offs at twice the price, all the while being touted as the 'Latest Thing'...

The Question WAS NOT,
What does some tight as guy that can't keep up in the conversation think?

If you have the 'Better Idea' we would ALL LIKE TO HEAR IT!
I'm the one that brought the Motorcraft large cap and rotor upgrade to the BBS.
I'm the one that brought the TFI ignition coil to the BBS.
Why do you think they call it the 'Team Rush' upgrade? Or did that one get by you also...?

I'm NOT the one that made a dime from the upgrade, although several people sold inferior parts and incomplete kits, I never made a penney.
It was a gift, a freebie to keep the people here from making the mistake of a $500 DUI-HEI or $500+ Jacobs ignition, which half of the conversations here were b!tching about the ignition systems when I arrived here.
And against all advice at the time, I gave it away instead of trying to sell a kit.
And I took a lot of crap from the short-bus crowd when I first suggested it, but now it's a staple...
It's even been ripped off (with no credits) by the 'Monster Machine' magizines...

Now some pinhead thinks I'm working for stickers from MSD?!...

(Nice job defending the world being flat...)

And don't try the argument that someone else would have come up with it...
You had from '76 to 2000 to do that very thing, and not one of you came up with anything but throwing money at aftermarket ignition systems that weren't any better than the factory originals...
24+ years passed, and all anyone did was throw money down the drain...

It was <u>ME</u> that came up with using OTC Ford parts, so <u>DO NOT</u> try and tell me what will and won't work correctly.


All of these parts may have some short comings.... but they were built into millions of vehicles.... making them very easy to find.... and they are <u>very reliable for a daily driver or weekend warrior Jeep.</u>[/b]

[/ QUOTE ]

No pinhead,
If the factory parts were "<u>very reliable for a daily driver or weekend warrior Jeep.</u>", you would all be using the factory Jeep cap, rotor, plug wires, ignition coils, ect.

You don't listen, and you damn sure can't learn...
You also seem to have a real problem with keeping your mouth shut in situations you don't understand...

Now, spout off with something lame that makes no sense and has no factual content...
(... flatulation will offen occur shortly after death and throughout the decompisition cycle...)

RRich 09-11-2005 10:43 AM

Re: TFI and HEI what\'s the difference?
You hit it on the head!
The reason you see so many MSD's on race cars is they are free! They pass them out like peanuts on an airline.
And - if you win and have enough MSD stickers on yor car, the contigency money is great! They want you to have the box prominantly displayed in the engine compartment - but it doesn't have to be hooked up, just look like it!

The Jacobs "computerized" ===== Smoke and mirrors!
They claim at certain times under certain conditions they "intensify" the spark.

There is no time ever, no speed, no load, no conditions where the spark needs to be LESS than full output, how can you intensify something that's aready full?

DUI is a very pretty nicely done rebuilt distrubutor - polished, plated -- pretty! But in order to make it work properly on a Jeep you have to take off the "racecar" weights and springs, replacing with bone stock HEI.
And, install an adjustable vacuum advance to get the curve to match your carb.
If you are into "pretty" go for it.

RRich 09-11-2005 11:04 AM

Re: TFI and HEI what\'s the difference?
John - yes the Chrysler box is simple.
But it is not a performance upgrade.
It's the same as using stock points without the points - or you can even trigger it with points if you want.

Chrysler went to it to help control dwell variations. Their distributors had the bushings close together, made excessive shaft wobble, causing too much dwell and timing varations. Had trouble passing emissions. The points put a side load on the distributor shaft, causing it to vibrate at certain speeds, driving emissions way up. The electronic box triggered by a magnetic pickup helped - no side load to speak of.

Performance wise - available voltage, rise time is the same as Pertronics, points or the stock Duraspark. Spark duration was even shorter than the others.

The modules were very reliable - best around, but the dual ballast resistor was very troublesome.

RRich 09-11-2005 11:34 AM

Re: TFI and HEI what\'s the difference?
TR - yes, test equipment rarely is able to "go along" on a test ride - the power cord usually falls out.

But the seat of the pants "yup, misfires" doesn't get it either. It's a combination of both, plus experimenting, guessing etc.

Often test equipment does not pinpoint the trouble either - doesn't always tell you what's wrong - but it usually does tell you what isn't!

Picture lying on a table while gasping for air - One doc says "Smokey" says it's the heart that does that. Another says Bubba's article says it's the lungs.

"It's OK TR, we have both in stock. We'll try one, then the other."

You'd suddenly become more of a believer in test equipment.

Hopefully you'll never have to face that.

Junk Yard Genius 09-11-2005 02:37 PM

Re: TFI and HEI what\'s the difference?

That snapper-head chaps my ass...
Takes my upgrades, trys adding a HEI module, screwed that, and declares himself the last word in the subject.

This is the same guy that posted the nightmare of wiring that was installed so poorly I didn't even bother to comment...

Then questions my motives? Fuc$ him with a jackhammer...
He better hope we never meet face to face, or Lucy will have some 'splainin' to do...

as for 'test' equipment, put the ignitions system in an environment chamber, add two atmospheres, moisture, exhaust gasses oil vapor, liquid oil and liquid fuel, maybe some inorganic compounds fused to the electrodes, then we'll talk.

I have that very chamber, called the 'Crusher'.
The name should pretty much describe what happens to 'Theory' when the hammer falls.
You are in Cal, get a hold of Craig Railsback, head tech geek at Blower Drive Service and see what he thinks of the Crusher...

JeepDaddy 09-11-2005 03:14 PM

Re: TFI and HEI what\'s the difference?
I just bought one of these for my 304 for under $200 delivered:Proform HEI

I have the Prestolite so I didn't have much to upgrade. I haven't installed it yet, but it should work good.

jdoggmoney 09-11-2005 04:53 PM

Re: TFI and HEI what\'s the difference?
Used junkyard 6 cyl HEI -$25.00
Replacement Cap and Rotor -$30.00
AMC V8 Dist gear -$30.00
Ford 300 Plug wires -$22.00

Single wire hook up -Simple

Two years later, I've driven through more water than most in all tempurature extremes with no signs of skipping or missing.
My jeep leaps to life with the turn of the key every time.
I've gotten what I consider to be reliable spark from idle to occasional spurts of 4000rpm.

HEI and don't look back [img]/ubbthreads/images/graemlins/grin.gif[/img]

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