TMU

I currently have an Accel 37100A which was apparently a dual point, but has been switched to electronic. It still has separate coil.

I see there are inexpensive new HEI tach drive distributors available, but I am not sure what's involved in changing over. What are my best options as far as replacing my current distributor?

Engine is a mild performance 350.

Big2Bird

This one is good, has smaller cap, but needs an MSD box:
http://www.msdignition.com/Products/...m_Advance.aspx

This one is good, does not need a box, but has the larger HEI cap:
http://performancedistributors.com/p...acuum-advance/

You CAN order it with/without vacuum advance.

I have worked on both. Both are good units.

doorgunner

From my learning experience/failures........here is something that MUST be done to avoid early electric component failure.......

First......make sure your cable-driven tachometer works properly before you invest in a new distributor.....you can connect a good tach cable to the tach.....then drive the other end of the inner cable with an electric drill set to LOW SPEED!

Buy a "decent/dependable" aftermarket distributor (FYI: internal parts alone cost $125+.....add the cost of a tach driven housing.....you are looking at $200 for a tach-drive distributor (maybe less if you buy a "NEW ITEM" meaning a manufacturer is offering a "first-run" off the production line to get sales started)

The firewall ignition wire from INSIDE the firewall engine harness connector all the way to the coil/distributor MUST be removed and replaced with a 10 or 12 ga. copper strand wire unless the wiring harness already has a copper-strand ignition wire (the original ignition wire in older cars is a special RESISTOR steel stranded wire that will not supply the correct voltage/amps to the upgraded distributor).

A new tach cable is needed.

Allow an hour or two to make the change-over.....especially if the ignition wire at the firewall has to be replaced.

Other members will post replies if I forgot anything.

TMU

Wish I could just replace with another electronic tach drive distributor, but they seem to more rare and much more expensive than the HEI tach drive units.


Thank you doorgunner

TimAT

What is your goal? Are you having problems with the Accel distributor or tach drive?

I'm running a MSD tach drive that has a pickup coil in it (no points) and the original K-66 GM TI amp and coil. I also have a Mallory CD ignition box mounted and wired, just not plugged in. Nothing like backup.

doorgunner

OOOPS! I just ASSUMED that he did NOT have a tach drive attaching point on his current distributor!

TX-Techman

I upgraded to a Mallory SSI and had Redline convert my Tach to electronic. They use your original faceplate and needle so it looks stock and works great without the hassle of the cable and components for the tach drive. I also converted all the instrument panel lamps to LED during the process.

TMU

Had a pinging problem develop and have ruled out just about everything but the distributor. As its some kind of electronic retro fit frankenstein distributor I figured probably best to replace it. Just hoping for a reasonably simple solution

TimAT

Do a full check of your timing- initial advance, advance curve (when advance starts to come in) and what the total advance is. If the mechanical advance is stuck, you could be running full advance all the time. And that could get you a ping. Too much initial advance could too. Most of the electronic retrofit (points eliminator) systems are pretty good. Unless it's installed so it's advanced, but that would show with a check of the timing.

TMU

I could not see the hole in the side before because the coil was in the way. I am assuming the adjustment screw is for the advance? As the distributor was tight and the screw had not been moved why would it suddenly cause pinging and should I even try to adjust it?

These are ebay pics, but its the same model as mine and looks like mine

jstrime

I put a Mallory Unilite with the tach drive on my '72 LT-1 and no issues whatsoever. LOVE it!

MelWff

You said you have no points so the screw in the picture may not exist on your distributor. Accel has precalibrated that distributor for 24 degrees of advance plus setting your initial for 12 will give you the correct 36 degrees total. The link below explains how the timing is set in the distributor when new. On the other hand this was intended to be a race only distributor, it has no vacuum advance which is highly beneficial for a street driven vehicle.
http://prestoliteperformance.com/med...tor_37000A.pdf

TMU

I removed the top as described in the document and its a dual point. I feel like an idiot because I had not seen one with a cover over the points and assumed it was electronic. So now I am assuming whole pinging issue could be caused by dirty or bad points. Do I replace or try to clean? I'll need to get a dwell meter.

redvetracr

there is nothing wrong with a well set-up factory tach drive distributor.

MelWff

The points aren't going to cause pinging themselves. The only effect they would have is if the dwell is off enough to advance the timing. Set the dwell and then set the timing to 12 degrees.

AIP

Here are all the popular electronic options for Corvettes using mechanical tachs, you'll need to do some homework to determine which will be the best fit depending on your specific needs:

HEI Distributor (Large Cap) with tach drive:
PROS - Easy all in one stand alone system, replaces entire existing
ignition, allows for connection of the mechanical tach cable, mid range
cost, most reliable.

CONS - Factory Chrome shield no longer fits, non-factory look, requires
new plug wires 8mm or larger with female style boot terminals for male
style cap.

Here is a good example:

ZIP Products HEI

Electronic Conversion kit for OEM distributor:
PROS - Retain factory look, low cost, replaces points without changing
other parts.

CONS - Worn metal moving parts inside distributor remain same.

Here is a good example:

Pertroix Electronic Conversion Kit

Performance Electronic Distributor (Small Cap):
PROS - Retain factory shield, best performance, allows for connection of
the mechanical tach cable.

CONS - Expensive, requires an external box and 12 volt coil, longer
install time, requires new plug wires 8mm or larger with female style
boot terminals for male style cap.

Here is a good example:

MSD Performance Distributor


Performance Electronic Distributor (Small Cap) with built in control module:
PROS - Retain factory shield, best performance, Easy install, allows for
connection of mechanical tach cable, low cost.

CONS - requires an external 12 volt coil, requires new plug wires 8mm or
larger with female style boot terminals for male style cap.

Here is a good example:

AIP Dragon Fire Performance Distributor

Big2Bird

All? Nope. Not all.

MelWff

thread was two years old

1960

WHY do you have to replace the tach cable ?