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Mon Feb 01, 2016 11:58 am

I've been building this engine for a few years now. Slowly but surely. It's like a jigsaw puzzle where you don't have all the pieces and the picture is for a slightly different puzzle.

I have a Mallory Unilite distributor and am trying to figure out how to set it up.
Which coil should I use and do I need a ballast resistor? Is this blue bosch one sufficient? http://www.airheadparts.com/vintage-vw-parts/vanag...cket-00012

Trying to figure this out is giving me a panic attack. I'm afraid I'll mess it up and it's slowing me down.

I'm not looking for anything fancy. I just really want to be able to drive it again.

Thanks in advance for your help.
Todd

1975 transporter
dual dellorto carbs
engine has been completely put together but not installed or started.

Mon Feb 01, 2016 12:07 pm

I think they want you to use a Mallory coil and a mandatory ballast resistor.

http://documents.holley.com/mallory_instructions_unilite_distributor_37_38_45_47.pdf

Mon Feb 01, 2016 12:23 pm

What is the model number for the Mallory Unilite distributor?

http://mallory-ignition.com/

Mon Feb 01, 2016 12:35 pm

Any 12v coil with 1.5 ohms or greater primary resistance will work with a Unilite module. Primary resistance is measured between the two metal tab posts, (terminals #1 and #15,) and genuine Bosch blue coils are usually around 3.4 ohms.

If your coil primary resistance measure 1.4 ohms or less, you may use a ballast resistor in series on the red wire that goes to coil terminal #15.

Robbie

Mon Feb 01, 2016 12:39 pm

I think the model is MAL-4554101.

Which of those figures in the linked installation instructions applies to my setup?

Thanks!
Todd

Mon Feb 01, 2016 12:42 pm

gelos wrote: I think the model is MAL-4554101.

Which of those figures in the linked installation instructions applies to my setup?

Thanks!
Todd

That depends on the primary resistance of your coil. It will most likely mirror figure two.

Robbie

Mon Feb 01, 2016 2:45 pm

asiab3 wrote: gelos wrote: I think the model is MAL-4554101.

Which of those figures in the linked installation instructions applies to my setup?

Thanks!
Todd

That depends on the primary resistance of your coil. It will most likely mirror figure two.

Robbie

John at Aircooled wrote IMPEDANCE which is different than RESISTANCE.

I also read 14 other threads asking the same question and the question of ballast resistor came up quite a few times. The answers posted were always something like "XYZ says that... ."

Here is what Mallory wrote on the sheet for the 45 series:

IMPORTANT
Before installing the UNILITE® Distributor, make sure that your vehicle is equipped with an ignition ballast resistor (or loom
resistance wire) in the wire between the ignition switch and the coil (+) terminal. Check a service manual for your vehicle to
locate the ignition ballast resistor (or loom resistance wire). If your vehicle is not equipped with an ignition ballast resistor,
install a Mallory Ignition Ballast Resistor Part No. 700 in the wire between the ignition switch and the coil (+) terminal. Failure to
use an ignition ballast resistor will eventually destroy the UNILITE® Ignition Module.

It goes on to say that if a CD system is being used between it and the coil that does not apply. My suggestion is when in doubt check with Mallory customer service.

~~~~~~~~

Mon Feb 01, 2016 3:23 pm

Quote: make sure that your vehicle is equipped with an ignition ballast resistor (or loom
resistance wire) in the wire between the ignition switch and the coil (+) terminal.

I saw that in some of the searches I made. How do I check that?

Also I'm not sure what you mean buy "CD system". Do you mean music?

I'm apologize for being slow. I don't know much about the electrical part and I'm not sure where to look for help. I'm kind of desperate for advice. :oops:

Also complicating matters is it's been a while since I removed the engine and some of my wire labels have fallen off. I know some wires are unused and some are for the fuel injection and no longer used.

Much appreciated,
Todd

Mon Feb 01, 2016 3:46 pm

gelos wrote: Quote: make sure that your vehicle is equipped with an ignition ballast resistor (or loom
resistance wire) in the wire between the ignition switch and the coil (+) terminal.

I saw that in some of the searches I made. How do I check that?

Also I'm not sure what you mean buy "CD system". Do you mean music?

Hi Todd,

No VWs (that I know of) came with a specialty loom resistance wire. If a ballast resistor was installed, it would be a few inches long and probably a rectangle, added into the #15 terminal of the coil wire. Here is what the "Mallory 700" resistor looks like:

CD system is a "Capacitive Discharge" ignition system, which is better suited to a high RPM performance engine than a typical "Kettering" (points and condenser) style ignition system. CD systems typically use a modified coil, an ignition box, and a distributor with an optical or magnetic trigger instead of points.

SGKent wrote:

John at Aircooled wrote IMPEDANCE which is different than RESISTANCE.

I also read 14 other threads asking the same question and the question of ballast resistor came up quite a few times. The answers posted were always something like "XYZ says that... ."

Here is what Mallory wrote on the sheet for the 45 series:

IMPORTANT
Before installing the UNILITE® Distributor, make sure that your vehicle is equipped with an ignition ballast resistor (or loom
resistance wire) in the wire between the ignition switch and the coil (+) terminal. Check a service manual for your vehicle to
locate the ignition ballast resistor (or loom resistance wire). If your vehicle is not equipped with an ignition ballast resistor,
install a Mallory Ignition Ballast Resistor Part No. 700 in the wire between the ignition switch and the coil (+) terminal. Failure to
use an ignition ballast resistor will eventually destroy the UNILITE® Ignition Module.

My suggestion is when in doubt check with Mallory customer service.
~~~~~~~~

I think the pages of questions regarding ballast resistors come up because of the fascination with American Iron having externally resisted coils. That PDF might be an old copy; on their website, and on the sheet that I have in front of me with my Mallory Unilite, they both say:

Quote: What coil should I use for my Mallory Unilite distributor, and/or Mallory Hyfire CD ignition box?

A: All Unilite distributors need coils with a minimum amount of 1.4 Ohms primary resistance. Coils are 12 volts; however, they do have different amounts of primary resistance, which is measured in Ohms. You can still use a coil with less than 1.4 Ohms, but you must install a Ballast Resistor (Mallory #700)

Which, to me, seems like an updated version of the online PDF.

I don't think John@aircooled's use of impedance vs. resistance should be read into too deeply; when I spoke to him years ago before buying the Mallory he explicitly stated that the stock resistor coil and resistor spark plug wires were a perfect match for the Unilite distributor. (I don't like people who use themselves as a case study, but I did have about twenty thousand miles with a 3.4 ohm coil and my Unilite setup before I changed induction and ignitions systems last year. 8) )

Checking with Mallory would be the 100% way to go, but good luck, since they were recently bought out by MSD and the Unilite line of products was discontinued.

Robbie

Mon Feb 01, 2016 4:07 pm

Thank you so much I really appreciate it!

Mon Feb 01, 2016 4:08 pm

gelos wrote: Thank you so much I really appreciate it!

No problem. I still recommend calling Airhead Parts and asking what the resistance is on that coil, then checking with Mallory to see if it 100% compatible.

Robbie

Mon Feb 01, 2016 4:16 pm

Will do!
I feel better now that I have more of plan.

I love tinkering with things but it can get overwhelming at times.

Todd

Mon Feb 01, 2016 4:24 pm

gelos wrote:
I feel better now that I have more of plan.
I love tinkering with things but it can get overwhelming at times.

For big projects, I make a pact with myself: do ONE thing every day. No matter how big or small, doing SOMETHING keeps us focused and honest with the project. I'm going through a massive engine refresh on Mom's bug right now, and I have parts in two different cities, and two shops working on stuff at the same time. My head is spinning with it all, but that's ok, because today I reinstalled the gas flap. 8)

Mon Feb 01, 2016 4:42 pm

That's good advice. I try to do that myself but I'm not consistent.

We're also starting a kitchen remodel which doesn't help. So many tile options!

Mon Feb 01, 2016 4:49 pm

thanks Robbie.

The date on that looked like 5/2013. I couldn't find anything else tangible. Other than NOS stock, Mallory is an excellent choice as long as the advance curve gets set right.

The idea behind ballast resistors is easy. Most cars were 6V until the mid 60's. Then 12V cars became very popular. Most coils were 6V at that time. Manufacturers often installed a 6V coil, used 12V on them when starting and 6V running, hence a ballast resistor. In the Mallory situation Mallory was trying to dampen the current flow. BUT .... where the question "do I or don't I use a ballast resistor" becomes relevant, is if the coil is already built to dampen current at 12V, combined with plug wires that are resistance wires, and the plugs have a built in resistor... . When we add a ballast resistor to all those different current dampeners we may loose significant spark. On the other hand who wants to burn up a new Mallory.

Figured since they warranty it they would know. :) Someone running one for 5 to 6 years and 80,000 miles on a bus could also tell someone whether they need a ballast resistor or not.

Mon Feb 01, 2016 4:55 pm

When in doubt install a Ballast Resistor.
http://www.speedwaymotors.com/Mallory-Ignition-700...AmtI8P8HAQ

Good luck
Tcash

Mon Feb 01, 2016 8:50 pm

Looks just like the ballast resistor on my old Mercedes. At start-up, full voltage is shunted around it from the starter pull-in to the coil, so full current is applied to the coil. During running, voltage goes thru the resistor dropping voltage and reducing wear on the points.

Mon Feb 01, 2016 10:53 pm

1967250s wrote: Looks just like the ballast resistor on my old Mercedes. At start-up, full voltage is shunted around it from the starter pull-in to the coil, so full current is applied to the coil. During running, voltage goes thru the resistor dropping voltage and reducing wear on the points.

Sounds like it could be tied into the CSV #50 circuit on Bosch fuel injection. That's easy enough to do for us with a diode to prevent back-feeding after startup, no?

Robbie

Tue Feb 02, 2016 1:21 am

Sounds workable, except I truly believe in my Pertronix. All points are updated on my rides. That would be like going back to 8 tracks.

Tue Feb 02, 2016 11:31 am

1967250s wrote: Sounds workable, except I truly believe in my Pertronix. All points are updated on my rides. That would be like going back to 8 tracks.

Actually Pertronix is more like a poor man's Mallory system. Good points are more predictable than a Pertronix. I KNOW my bluestreak points will wear out in 12,000 more miles. Do you know when your Pertronix will fail?