I hear so many myths and partial truths about Mallory ignition modules that I thought I'd try posting the facts on a the forum to clear things up.

Mallory has three types of modules (not including the new rev limiting HEI module) that fit inside the distributor: Unilite, Magnetic Breakerless Ignition (MBI) and the new E-Spark. The Unilite and E-Spark are similar but the E-Spark is manufactured on automated equipment to reduce manufacturing costs so that the E-Spark conversion kits can be sold at about the same price as a Pertronix. The MBI uses a similar circuit but uses a magnetic pickup as a triggering device rather than an optical pickup.

The Unilite and the MBI are available in complete Mallory distributors. The Unilite and the E-Spark are available in conversion kits for stock type point distributors.

All three modules were originally designed to replace point style ignitions. Point style ignitions use coils with high primary resistance and ballast resistors (or resistor wires such as used in AMC, Ford and GM). Thus, the Mallory modules were designed to use a ballast or resistor wire.

Unilite, MBI and E-Spark modules (and Pertronix) are basicly electronic replacements for points. They are not amplifier boxes like a Hyfire or an MSD box. They are simply a way to get rid of the points. The spark output is usually a little higher than points due to the increased dwell time (and you don't have to worry about point bounce) but the output is not significantly greater than points. HEI type modules or external amplifier boxes are the only way to significantly increase spark output.

All three Mallory modules wire the same way. There are three wires:

The brown wire is grounded to the engine. Make sure you also have a good ground cable/strap between the engine and the frame/battery. Do NOT ground the brown wire from the module directly to the frame or battery. If you do, the brown wire will become a ground for the starter during cranking which will melt the brown wire and take out the module.

The green wire connects to the negative side of the coil.

The red wire can connect to the positive side of the coil but it's better to connect it to the high side (12 volt) of the ballast resistor. Remember, the ballast or resistor wire is there to limit the current through the coil and the green wire. The red wire prefers to see full battery voltage. If you connect the red wire to the positive side of the coil (which is also the low side of the ballast) the engine may not start as easy especially if the battery is low. If your car has a resistor wire rather than a ballast, you can either hook the red wire to the positive side of the coil, or better yet, find a place to hook it that will feed the red wire full battery voltage whenever the key is on.

If you are also using an external box such as a Hyfire or MSD, follow the wiring instructions that come with the box as the module will need to be wired differently. A ballast or resistor wire is not needed when using an external box since all the current for the coil goes through the box rather than the module. (When used with an external box, modules and points last almost forever because very little current goes through them). Some people like to leave the ballast or resistor wire in place when hooking up an external box (it won't hurt anything) so that if the box fails you can bypass the box and still get home running on the module alone.

I often hear people ask what voltage they should have at the coil when running a Mallory module without an external box. The standard answer is about 7 to 10 volts measured at the coil with the engine running. However, while this is easy to measure, it is not the best thing to measure since the voltage will vary depending on the voltage output of the alternator. What really matters is the total resistance of the primary side of the ignition. This includes the ballast (or resistor wire) and the primary resistance in the coil (measured with an ohm meter between the positive and negative terminals on the coil). The ideal total resistance is a minimum of 1.4 ohms and a maximum of about 3.5 ohms. More than 3.5 ohms is safe for the module but the spark may be too weak for optimum performance. Use an ohm meter to measure the resistance across the ballast and add that to the amount of primary resistance in the coil. The total should be between 1.4 and 3.5 ohms. You may need to measure the resistance of the ballast after it has warmed up since some ballast resistors increase in resistance with temperature. If your car has a resistor wire rather than a ballast it can be difficult to measure the resistance in the wire as the wire gets lost in the harness. If so, assume that the resistance in the wire is about 1.0 ohms which is typical.

Some coils have so much primary resistance that a ballast resistor or resistor wire is not necessary. Mallory has two new Promaster coils that have all the resistance built into the coil (29450 and 30450). Using these coils, no additional resistance is needed.

Having all the resitance built into the coil has drawbacks however. The coil will run hotter which will reduce the life of the coil somewhat. Also, high resistance coils are not recommended for use with external boxes as the coils will overheat and fail (sometimes even explode!).

Don't use solid core plug wires with any electronic igntion.

If you weld on the car, disconnect the module before doing so.

Unlike popular opinion, the standard Pertronix module also requires a certain minimum resistance. When using a Pertronix on a car that was using points, no ADDITIONAL resistor is needed, but this is also true for Mallory modules. Pertronix also sells their own coils with high resistance so that a ballast is not needed.

Now you know the real deal.

Good info!

I've run Mallory equipment for years! Using a Comp 9000, Promaster coil, and Hyfyre box with RPM limiter now.

You refer to the E-Spark conversion. I am not familiar with that and did a search but could find no info. Can you post a link? A friend of mine has an old flathead six Mopar and wants to convert to pointless ignition. Petronix doesn't have anything to fit and I'm curious about the E-Spark conversion you mention, or any suggestion to upgrade my friends "flattie".

The E-Spark is brand new. Being released this week at PRI show. We have a few flyers but nothing I can link to yet.

None of the Mallory conversion kits will fit the stock flathead 6 Mopar distributor, however, we may have a Unilite distributor (part # 452000001) that will fit. It fits 1941-1959 Chysler 6 cylinder. Does that sound like the right one?
The distributor is special order. Call Dennis at Mallory 775-882-6600 to make sure it will fit and to order.

Thanks!!!

I'll pass the info along.

I've been running a Comp 9000, Hyfire IV, and Promaster 29440 coil for over 4-1/2 years without any problems. It was in the car when I got it. My question is, should this setup have a ballast resitor. AFAIK, it has never had one. I know it doesn't have a ballast wire. As I said, it has been working flawlessly for quite a while. Thanks

Pat, I'm running a comp 9000 and a Hyfire IV also but I am running a ballast resister on mine. I believe that it is an old Mopar style resistor. I have instructions for the Hyfire IV someplace that recommend one and give the type. I can find them if you are interested. I mounted it up under the dash,no one would ever know unless I told them that it was there.

As I said above, a ballast resistor is not needed when an external box (Hyfire, MSD etc) is used. However, having one doesn't hurt anything and if you have one wired into the circuit you can bypass the box and run the engine on the module alone if the box fails.

RobbMc
i have a Mallory Unilite and an old mallory voltmaster coil in my 66 chevelle. these came with the car when i bought it, and i dont have any paperwork for them. this coil evidently isnt made anymore and i cant find a listing on it on mallory's website.

the coil part number is 28675, it says Mark 2 Voltmaster and it also says 12 volts right between the terminals on top. when i bought my car it was and still is setup with a ballast resistor, but im not sure that this coil needs one. can you verify this?

also my distributor uses a little key to set the amount of mechanical advance, but it was lost by the PO. can i get a replacement? have a part number?

thanks

Originally posted by RatONaStick:
RobbMc
i have a Mallory Unilite and an old mallory voltmaster coil in my 66 chevelle. these came with the car when i bought it, and i dont have any paperwork for them. this coil evidently isnt made anymore and i cant find a listing on it on mallory's website.

the coil part number is 28675, it says Mark 2 Voltmaster and it also says 12 volts right between the terminals on top. when i bought my car it was and still is setup with a ballast resistor, but im not sure that this coil needs one. can you verify this?

also my distributor uses a little key to set the amount of mechanical advance, but it was lost by the PO. can i get a replacement? have a part number?

thanks The old Voltmaster coil was designed before the Unilite was around. It is a very high inductance coil designed to get the most out of points. It is similar to the old big yellow Accel Supercoil. It is a poor choice for electronic ignition and may cause the module to overheat. You should replace it with a coil designed for electronic ignitions like a 29440 or 29216. Even a stock points coil would be safer for the module.
In the meantime, DO NOT remove the ballast resistor. That would make things even worse.

The degree key you need depends on the type of advance you have. If the distributor is more than seven years old, it probably has a YL advance and you need curve kit 29015. If it is newer and has a YT or YH advance (look for gold colored advance parts) you need curve kit 29014. The kits come with degree keys and variety of springs.

thanks for the reply! much appreciated.

Can you tell us more about the HEI module with rev limiter like cost and availability by itself or complete DIS. How do you set the limit?

Thanks for the info graemlins/thumbsup.gif

The 75 series rev limiting billet HEI distributors (part number 7548201 for Chevy V8) should be available in a week or two. I thought they would be shipping a month ago but Thankgiving and inventory week slowed things down.

These distributors have billet aluminum housings, an adjustable Mallory YH mechanical advance, an adjustable vacuum advance, ball bearing shaft support and a built-in Hyfire with rev limiter. The limiter is adjustable via little switches; no rpm plugs required. They accept standard caps, rotors and coils.

These distributors have nothing in common with the low cost Mallory 85 series distributors except that they will accept the same cap and rotor. The 85 series are just low cost copy of a stock HEI distributor.

The rev limiting HEI modules may be sold seperately at a later date. We are still testing them in all the different stock and aftermarket HEI distributors.

Originally posted by RobbMc:
The 75 series rev limiting billet HEI distributors (part number 7548201 for Chevy V8) should be available in a week or two. I thought they would be shipping a month ago but Thankgiving and inventory week slowed things down.

These distributors have billet aluminum housings, an adjustable Mallory YH mechanical advance, an adjustable vacuum advance, ball bearing shaft support and a built-in Hyfire with rev limiter. The limiter is adjustable via little switches; no rpm plugs required. They accept standard caps, rotors and coils.

These distributors have nothing in common with the low cost Mallory 85 series distributors except that they will accept the same cap and rotor. The 85 series are just low cost copy of a stock HEI distributor.

The rev limiting HEI modules may be sold seperately at a later date. We are still testing them in all the different stock and aftermarket HEI distributors. Thanks for the info Rob but educate me. What is the Mallory YH advance?

What about about the Hyfire module is it basically a capacitive discharge DC-DC converter?

Good info on the Mallory ignition components! I had(have) a Unilite distributor and coil (can't recall the p/n's right now) and have been pretty pleased with them so far...had run them for some time, although been sitting just as long now...

One question I had is with the module inside the distributor...should there be some type of 'heat grease' between the module and dist. housing? If so, what kind is it and where would I get some? I thought I had heard/read this some time ago and wanted to check while I'm thinking about it (gonna be putting back together the car and getting what I need now ;) )...Thanks!

The YH mechanical advance is the newest Mallory advance. It has been around for about 5 years and is used in most (but not all) Mallory distributors. The amount of advance can be adjusted from zero (locked out) to 28 degrees by loosening two screws and rotating a stop plate.

As a mechanical engineer and not an electrical, all I can tell you is that the Hyfire circuit is similar to the Hyfire 3RLI box. I've had one of the 75 series on my car for eight months now. Works really well. Keeps plugs very clean and engine starts instantly.

Yes, there should be heat transfer grease on the bottom of the modules. If you need some, just use the same stuff that the parts stores supply with the HEI modules.

How about the rate of advance. How is that controlled?


I want one graemlins/thumbsup.gif

The rate of advance is controlled by springs. The standard curve starts at about 1100 rpm and has 20 degrees at about 2200 and 24 degrees at about 3000 rpm.
If you want to change the rate of advance you have to order a spring kit (Part #29014). The kit comes with a selection of springs, curve sheets and degree keys. The degree keys allow you to adjust the amount of advance without trial and error.