Tach Drive HEI Distributor Recommendations

Kid Vette

Kid Vette

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I have recently been having intermittant hard starting problems that I think may be related to ignition. I presently have a MSD distributor and 6AL box. I see tach drive HEI's listed on fleabay anywhere from $85 to $200. Any advice?

I know Bird will insist that I keep the MSD. :rofl:
 
Nothing wrong w/ mag trigger tach drive MSD (and it's expensive too @ 400 bones) it's the box that sucks. However I doubt the hard starting has anything to do with the box, either it works or it doesn't.
 
For ALL you guys that INSIST on having a stupid box, IF you REALLY insist on having/keeping one, Chrysler makes a HP box that's good to 9,000 RPM, and is VERY similar to the original TI ignition with modern parts. IF you guys want, I'll post a link.;)
 
big2bird said:
For ALL you guys that INSIST on having a stupid box, IF you REALLY insist on having/keeping one, Chrysler makes a HP box that's good to 9,000 RPM, and is VERY similar to the original TI ignition with modern parts. IF you guys want, I'll post a link.;)
Click to expand...
Please do.
 
Here's the problem. Occasionally, when I go to start it; it spins but won't fire - just an occasional burp through the carb. If I keep cranking, it eventually starts and idles perfect. No black smoke as if it was flooded and it doesn't act as if its clearing itself out. This can happen if the engine is warm or cold - doesn't matter.

And a couple weeks ago while I was driving to work, it cut out just briefly a couple times. Then at lunch it started running progressively worse until I could barely keep it running. The tank was almost empty so I decided to limp into a gas station and fill up. When I went to start it, it fired right up and idled perfect. I took off and it was like nothing was ever wrong. I just can't believe a fuel problem could come and go that quickly.

Ideas?
 
MAKE DAMN GOOD AND SURE, the + voltages there are supposed to be there are IN FACT THERE during the CRANK mode....

sometimes you have the rong wire and they are NOT.....
prove with a lightbulb or a DVM....

the symptom MAY be crankkkkkkkkkkkkkkk forever then release the key in total abject DISCUSST and the thing fires off when you do that.....

:goodnight::flash:
 
big2bird said:
Twin_Turbo said:
However I doubt the hard starting has anything to do with the box, either it works or it doesn't.
Click to expand...

Marck, sometimes they do turn to shit before they die. (Like when they are new):quote: LOL
Click to expand...


I never had that happen, either they crap out completely or not at all...must have been lucky. Always MSD boxes that crapped out, mallory & crane never.

Now, if you want a shitty box please DO get the chrysler box. These things crap out so often it's not even funny. When you put headers on a mopar you're asking for trouble. The placement was probably heat mapped from the factory w/ the cast manifold but w/ headers they don't last long at all.

Also, there are several versions, an orange stock one, a chrome one and a gold one. The gold one is the race version, the chrome is hot street, the orange is stock. You are talking about this right? The orange box on the firewall?

24a57ebc9a3a68.jpg

Another draw back is, it doesn't deliver the oomph that a HEI does and you still need a ballast resistor (you can see it in the pic above between the wiper motor and voltage regulator)

If you want reliability stick with the GM HEI, it's next to impossible to beat

Electronics on mopars is the devils work anyway...people mock lucas the prince of darkness but this mopar stuff is a fire waiting to happen. I have a video where you can see a sudden plume of smoke, turned out one of the brushes on a dual field squareback (ext. regulated of course) alternator was worn and the wire came undone, touched the case, shorted the whole damn thing out and burnt the wire all the way back to the firewall mounted voltage reg. Lucked out though, could have gone straight behind the dash and zapped the amp meter in which case no power anywhere and a mile of burnt wires.

Here's the vid, sorry for the OT.

[ame]http://www.youtube.com/watch?v=qxIF3qYsWTQ[/ame]
 
Davis Unified Ignitions? Their customer service isn't quite what I'd expect for that kind of money. A guy I know bought a dizzy a couple of years ago and was working on his engine and all, with us poor saps here it can take quite a long time to finish a big project w/ shipping and all..so it took him about 2 years to get to the point where he installed the dizzy and the thing wasn't working right, didn't want to spin the motor over 4500 rpm. Warranty? No such thing!
 
FWIW, I'm running a MSD tach drive dizzy and a Summit branded Mallory box. No problems at all. And the $159 box is a heck of a lot cheaper than the MSD box- and so far, more reliable.
 
Over the decades, Chrysler electronics/electricals have been somewhat ......exploratory, to be KIND.....

JUNK to be honest....

:trumpet: ALMOST makes Lucas look good.....


almost....


wearing a respirator.....

upwind.......

:harhar:
 
just checked out summit, the boxes don't look the same but the specs are identical...how did you know they are mallory boxes? Forgot what the old Hyfire box looked like, maybe the summit is the old case?

sum-850600_w.jpg
Brand Summit
Manufacturer's Part Number SUM-850600
Part Type Ignition Boxes
Product Line Summit Racing Street & Strip® Multi-Spark Digital CD Ignitions
Summit Racing Part Number SUM-850600
Ignition Box Output Capacitive discharge
Circuitry Digital
Rev Limiter Yes
Timing Retard None
Data Acquisition No
CD Voltage Output to Coil 520 V
Current Draw 0.6 amps per 1,000 rpm
Spark Output (millijoules) 135 Millijoules
Minimum Operating Voltage 8 V
Maximum Operating Voltage 16 V
Length (in) 8.000 in.
Height (in) 2.750 in.
Width (in) 3.500 in.
Ignition Box Color Black
Coil Included No
Warranty One-year warranty
Quantity Sold individually.


maa-6853m_w.jpg

Brand Mallory
Manufacturer's Part Number 6853M
Part Type Ignition Boxes
Product Line Mallory HyFire VI-AL Digital CD Ignitions
Summit Racing Part Number MAA-6853M
Ignition Box Output Capacitive discharge
Circuitry Digital
Rev Limiter Yes
Timing Retard None
Data Acquisition No
CD Voltage Output to Coil 520 V
Current Draw 0.6 amps per 1,000 rpm
Spark Output (millijoules) 135 Millijoules
Minimum Operating Voltage 8 V
Maximum Operating Voltage 16 V
Length (in) 8.000 in.
Height (in) 2.750 in.
Width (in) 3.500 in.
Ignition Box Color Red
Coil Included No
Warranty One-year warranty
Quantity Sold individually.
 
big2bird said:
........., sometimes they do turn to shit before they die. (Like when they are new):quote: LOL
Click to expand...

Where's the polite "I agree" icon?

In 1974, I converted my '69 to electronic ignition using a Hays Magna-Pulse system. It had a magnetic pickup for the distributor, and the usual potted up box with an internal PC board. The car ran fine for about eight years, until it started to misfire under higher RPM loads. Starting and normal driving was fine. I took it (the distributor and box) into work one day and hooked them up on the bench. The oscilloscope showed that the module had a problem. The module had a slow gradual failure curve to it. It wasn't a sudden failure.
 
Kid Vette said:
Here's the problem. Occasionally, when I go to start it; it spins but won't fire - just an occasional burp through the carb. If I keep cranking, it eventually starts and idles perfect. No black smoke as if it was flooded and it doesn't act as if its clearing itself out. This can happen if the engine is warm or cold - doesn't matter.

And a couple weeks ago while I was driving to work, it cut out just briefly a couple times. Then at lunch it started running progressively worse until I could barely keep it running. The tank was almost empty so I decided to limp into a gas station and fill up. When I went to start it, it fired right up and idled perfect. I took off and it was like nothing was ever wrong. I just can't believe a fuel problem could come and go that quickly.

Ideas?
Click to expand...


Previous owner of my '73 had a similar problem. He chased a fuel problem for awhile before finding a loose connection in the ignition circuit (I believe he said it was one of the wires connected to the distributor).

DC
 
Twin_Turbo said:
Davis Unified Ignitions? Their customer service isn't quite what I'd expect for that kind of money. A guy I know bought a dizzy a couple of years ago and was working on his engine and all, with us poor saps here it can take quite a long time to finish a big project w/ shipping and all..so it took him about 2 years to get to the point where he installed the dizzy and the thing wasn't working right, didn't want to spin the motor over 4500 rpm. Warranty? No such thing!
Click to expand...

Sorry to hear that.

The tach gear on the first one I got went out after a couple hundred miles. Sent it back to them about a month or more after I bought it. They sent me another one right away. The guy on the phone was helpful before I bought and when I had the problem. Good customer service as far as I am concerned.

Have about 1500 miles on it now. Hopefully I won't have any problems with it in the future.
 
From what I understand the limiting factor to the hei is the "in cap" epoxy coil due to heat increasing coil resistance.
Supposedly, switching over to an external oil cooled coil maintains good output and increases the rpm limit much better than even the fancy aftermarket in cap coils.`
Cap adapter MSD 8401

Last hei of mine that failed was back in 77, so that's fairly reliable.
Never have had a need to try this, my hei's work great, but this is a cheap enough mod to try anyway.
Never have used any aftermarket boxes.
 
If MSD could just make an HEI Streetfire with the tach drive gear, we would have a winner. Great unit for the $$. The DUI is good, and I have heard no complaints except TT. As for the Chrysler unit, placement is imperative. You can't cook them, but the race unit is good.
Lars and Mike will agree, the boxes are just trouble. Get an HEI and forget it, or use the points unit stand alone.
 
The old style Mallory box looks exactly like the current Summit box. The switching setup for the rev limiter, wiring diagram and color of the wires, even the insturction sheet is all the same with the exception of the wording being "Summit" in place of "Mallory". As TT pointed out, even the specs are the same. And one of the guys at Summit told me that they get them from Mallory.
 
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