after market distributor • The Dodge Challenger Message Board

by **gregvega** » 30 Oct 2006 22:23

What would be a good after market distributor on a 440 with factory style ignition box? Or a up graded box?

by **dave-r** » 31 Oct 2006 8:52

Nothing wrong with the Mopar Performance electronic ignition kit. It uses the same distributor as was used on mopars from around 1973 on. Only difference is it has a "performance" ignition curve built in. It is simple to install and comes with the correct factory wiring.

If you already have the factory "orange box" and wiring you can buy the distributor by itself.

If you want something more high tech (and more expensive) the MSD range of distributors is good. They do one that has everything built into the distributor. No external ignition units etc. Just bolt it in and go.

After that you are talking one of their billet racing distributors working with one of their capacitive discharge/multi-spark units.

by **fbernard** » 31 Oct 2006 9:02

It all depends on whether you want vacuum advance or not.
The Mopar Performance distributor is a quality piece. You may need to recurve it, as the springs are a bit light (get the spring kit with the distributor).

Most people I know (including a 9.6s Challenger) use it.

There's someone in the US who sells an adapter ring to use modern magnum distributor caps (with male terminals instead od sockets on the dist. cap).

The FBO custom units (http://www.4secondsflat.com/) have an good reputation.

And then there's MSD and Mallory. Both have good models, with and without vacuum advances.

Watch out though, the reluctor on the MSD units (#8546) will most likely be already rusty right out of the box. Not that it hinders the fit and function in any way, but it's strange, forking over 280 bucks for a great looking billet aluminum piece, and getting rusty parts to start with.

I have the MSD 8546 dist. (was in the car when I bought it) with a MSD Digital 6+ box (great box for a street/strip car). Works perfectly. Only thing that would be better would be male terminals on the distributor cap.

The electronic distributor Dave talks about only exists for small-blocks at the moment.

by **dave-r** » 31 Oct 2006 13:57

fbernard wrote:The electronic distributor Dave talks about only exists for small-blocks at the moment.

383-400 Dizzy

440 Dizzy

by **dave-r** » 31 Oct 2006 13:59

fbernard wrote:Watch out though, the reluctor on the MSD units (#8546) will most likely be already rusty right out of the box.

I think mine is polished or chromed or something. I will will check tonight. Can't take photos at the moment because my camera bust!

by **dave-r** » 01 Nov 2006 21:22

I checked inside my MSD billet dizzy and everything is as shiney as a new penny.

I wonder why yours was rusty fbernard? Who supplied it?

by **fbernard** » 02 Nov 2006 14:31

dave-r wrote:I checked inside my MSD billet dizzy and everything is as shiney as a new penny.

I wonder why yours was rusty fbernard? Who supplied it?

Every single one I've seen is like that. I even checked a brand new one (250 pounds!!!) at Santa Pod last July. A real beauty. Brand new, in the box, shiny and smooth billet aluminum. I opened it and started laughing. Sure, it was better than mine, but it was already starting to rot. The goddamn thing was brand new! Mine is like 10 years old, and spent 10 winters in an unheated (though not damp by any means) garage.
I have a second one from the same source (came with the car) that's for a B-block, never been used, and just as rotted as the RB one I'm using.

I checked for replacements yesterday, and I've seen that MSD now has a steel version (90 USD, ouch!) for 'ignition tuners', that can be filed for tuning. Looks like the same part I have in iron. Maybe steel will be less prone to rust, but it can't be made of stainless steel anyway, so why bother? I believe nickel or zinc plating (let's be cheap : zinc paint will work!) would be a good option for me. I only have to take it all apart... :s001:

by **dave-r** » 02 Nov 2006 16:04

Mine look plated.

I will have another look tonight and also take a photo because I just heard my new camera arrived.

by **dave-r** » 03 Nov 2006 22:19

The small brown marks in this photo are very hard to see without the flash. I can't make out if it is rust or grease. Could be rust though.

The flash really brings out the tiny detail.

by **fbernard** » 04 Nov 2006 12:13

Yours looks much better than mine.
I guess I should dismantle the B distributor I have, have the reluctor plated and swap int into the housing I'm using.

But that's Action #191 on my list right now, or something like that.

Don't you have problems with the cap always cracking ?
(mine always do after a time, usually at the small plastic window opening)

by **dave-r** » 04 Nov 2006 14:35

fbernard wrote:Don't you have problems with the cap always cracking ?
(mine always do after a time, usually at the small plastic window opening)

You mean the air vent (black in this photo)?

I have not used this distributor yet or in fact any MSD product in the past. Never had any problems with the old MP distributor caps but this is made from a slightly different type of plastic I think?

I am not sure why a cap would crack unless it was under stress of some sort?

by **Jon** » 04 Nov 2006 14:40

Nothing wrong with the Mopar Performance electronic ignition kit. It uses the same distributor as was used on mopars from around 1973 on. Only difference is it has a "performance" ignition curve built in.

I installed my electronic conversion distributor in 1980. Do you think it may have the "performance" ignition curve or did that come later?

Also still interested in a rev limiter using the factory system. Any manufacture's, part numbers,...

Thanks

by **dave-r** » 04 Nov 2006 14:43

Check to see if it has one light spring on one of the centrifugal weights.

by **Jon** » 04 Nov 2006 15:30

Dave, how do I tell if the spring is light? or is it a single spring I am looking for?
How about the rev limiter. I have blown at least two motors in the past due to over reving the engine. :s020:

Missed shifts now really scare me.

by **dave-r** » 04 Nov 2006 18:14

You should see one spring that looks finer than the other. It will be obvious to look at. See the springs in the photo of the MSD unit above? Yours will probably be more obvious than that and different colours. Although they are hidden in the base of a MoPar dizzy and hard to see.

I don't know of a rpm limiter that would work with the stock MoPar system. I am sure there must be one but I just don't know of one.

I am going to use a MSD system because I want two rpm limiters. One lower rpm limit for when the line lock is on during the burnout and one for the higher shift limit.

It will work with the stock dizzy but it will not look stock unless you hide it away.

by **fbernard** » 04 Nov 2006 19:22

dave-r wrote:I don't know of a rpm limiter that would work with the stock MoPar system. I am sure there must be one but I just don't know of one.

A simple rev limiter is the MSD 8728. It works only with stock systems, it mustn't be used with multi-spark boxes. So it's perfect for strock ignitions.

As far as I know, and for obvious reasons, there are no external rev limiters that work with CD ignitions.

My cap is not the same as yours at all, I have a dark red-brownwish one with sockets and one window on the bottom. I'd love to swap for that cap with terminals.
Come to think of it, my distributor is a pretty old version (and with a plastic baseplate), it's been ground for clearance and the product number isn't thre anymore. I thought it was the 8546 since it's the only comparable model in MSD's current line-up, but it's not. Maybe I won't fix it after all. One more thing to add on my Christmas list...

by **dave-r** » 04 Nov 2006 20:54

Yours does look as if it has seen better days....

by **fbernard** » 05 Nov 2006 9:48

dave-r wrote:Yours does look as if it has seen better days....

The funniest thing is that it works flawlessly. I just brushed everything, changed the springs and bushings.

by **Jon** » 05 Nov 2006 15:02

A simple rev limiter is the MSD 8728. It works only with stock systems, it mustn't be used with multi-spark boxes. So it's perfect for strock ignitions.

fbernard, thanks for the information I'm going to get one on order. You seem to know a bit about electrical. Any ideas why my orange box would fail repeatedly? This one is only 700 miles old. The only thing i messed with was changing the battery.

Thanks again

by **dave-r** » 05 Nov 2006 15:17

Can i just add my thoughts before he answers?

The orange box is really nothing more than a single transistor that acts like a switch. It is not an amplifier as such. The extra spark power comes from allowing the coil to charge for longer. Due to the long dwell angle a pointless distributor allows.

The #1 thing that kills transistors is heat. Keep it as cool as possible and it will last longer. Also makes sure you have a good solid connection to the air box. You need a good earth to the case and it also acts as a heat sink.

by **Jon** » 05 Nov 2006 15:41

Thanks Dave. I have the box mounted on the passenger side fender near the washer res. Should be pretty cool in that location. What did you mean "a good solid connection to the air box"?

by **dave-r** » 05 Nov 2006 15:56

The stock location is the air box (top half of the bulkhead).

by **Jon** » 05 Nov 2006 17:43

From what I have been reading the chrysler ECU's are poorly made and fail often. :roll:

And you are right Dave all that use this system should keep a spare in the trunk. :s021:

I am checking on an aftermarket system that is suppose to look stock and be more reliable. We'll see

by **fbernard** » 05 Nov 2006 19:53

dave-r wrote:Can i just add my thoughts before he answers?

Gave you a headstart there, didn't I?

My thoughts on this problem, although mine never gave up (I have the orange box on the convertible) :

Original electronic ignition cars (1972-) had the ECU on a bracket, on the firewall. Plenty of air circulating behind the bracket, so the bracket itself was probably acting as a heatsink (and of course, the transistors, at least for this kind of application, were of better quality then). Most cars that were retrofitted with electronic ignitions (and mine is no exception) have the box mounted directly to the firewall or inner fender. As Dave said, electronics and heat don't mix. I've even seen one car in which the inside coating had dripped from the ECU on the firewall (stock model, not orange box).
For american people out there, there are several replacement boxes available at parts stores (Napa and the like) that have a better reputation than the Mopar boxes. I'd say that Mopar has them made by the lowest bidder, and the components are not of the utmost quality.

That still doesn't explain their rate of failure, but I'd say that the components inside don't stand vibration and are not rated for automotive use.

Such problems happened twice recently to friends of mine. One was a real box failure, the other was a transient problem with the ballast resistor. Anyone using an ignition system with a ballast should also have a spare, or arrange the wiring in a way that lets you bypass the ballast easily (it's easier to think about this in a heated garage with lights on, than by the side of the road in winter, or under the rain, at night, with no tools).

the FBO system looks stock and is considered reliable by most people who talk about it (on moparts, mostly).

by **dave-r** » 05 Nov 2006 20:45

FBO products are good (Hello Don!) and they claim to tune things exactly for your application (such as the distributor and Demon carb) but from what I have seen they often get it wrong.

I always say the best tune is done by the user because every engine (and surrounding systems) is different even if they are the same spec.

by **Jon** » 06 Nov 2006 15:05

Thanks guys. The FBO package is the one I am looking at. I have read of positive results using the A688 package (some on Don's site). I need a cap and rotor anyways and the price is right in line. You can also swap local auto parts store replacements in a pinch without damaging the ECU or coil. They also provide a 2 year warrenty. Yes, even on electrical parts. :shock:

I will also look into devising a stand off for the ECU to help cooling.

As for the current supply of ECU's from Chrysler, the original installed in 1980 lasted until 2005. The replacement purchased in December of last year is already done. They just don't make em like they used to.

I can't see installing another unit from Chrysler that maybe from the same "batch" so the FBO is my logical choice. Will let you know.