Mallory Unilite Distributor #3772101

[BNewman]

Does anyone have any experience, good or bad, with the Mallory Unilite Distributor (3772101) for use on a stock '37 85hp flathead (21 bolt).
Or other thoughts...
Thanks

[bluardun]

Excellent, but you must use an alternator, not a generator.

[tubman]

Originally Posted by bluardun

Excellent, but you must use an alternator, not a generator.

I'm curious as to why this would be. Could you please explain further?

[BNewman]

thanks. good to note.
Bob

[rotorwrench]

A 12-volt generator would work as well as a 12-volt alternator but it depends on whether the car is set up for 12-volt negative ground or not. Most of the new electronic stuff is for 12-volt negative ground systems. A 6-volt positive ground system is another matter.

[BUBBAS IGNITION]

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Originally Posted by tubman

I'm curious as to why this would be. Could you please explain further?

The Mallory electronic dont like the irregular out and voltage swings coming from the generator !!

https://www.summitracing.com/parts/maa-29351

They do make a noise filter , however they are hard to get somedays....also must use a good coil to keep the current flow down...the MSD/Mallory coils are typically too low on resistance........

[flathead4rd]

Originally Posted by BUBBAS IGNITION

The Mallory electronic dont like the irregular out and voltage swings coming from the generator !!

https://www.summitracing.com/parts/maa-29351

They do make a noise filter , however they are hard to get somedays....also must use a good coil to keep the current flow down...the MSD/Mallory coils are typically too low on resistance........

What coil do you recommend? Make & Part number?

[tubman]

Originally Posted by BUBBAS IGNITION

The Mallory electronic dont like the irregular out and voltage swings coming from the generator !!

https://www.summitracing.com/parts/maa-29351

They do make a noise filter , however they are hard to get somedays....also must use a good coil to keep the current flow down...the MSD/Mallory coils are typically too low on resistance........

Mallory should have quit while they were ahead with the ole' "flattop".

[rotorwrench]

A plain old GM module is damn near bullet proof. I just wonder why they can't make a module that can take all the irregularities. I know it can be done but they just don't want to make the effort.

[BUBBAS IGNITION]

Originally Posted by flathead4rd

What coil do you recommend? Make & Part number?

Based on quality and availablility it changes somedays.
Heres the deal on a flathead (low rpm band and low compression) the 12 volt ignition needs a primary current of approx 3-4 amps. A napa IC12SB (1.5 ohms) and a 1.5 ohm resistor would be 3 ohms divided into 12 volts for a current flow of 4 amps. This set up has worked great forever.
Now to step it up just a bit I have been using a German made coil the Beru ZS172 blue at 3.3 ohms and no resistor for a current flow of 3.63 amps , i have shipped over 100 of these and they seem to work very well ! I still like the Bosch Blue # 00012 coil at 3ohms as well, just because it is shipped with a nice mounting bracket..
The main thing is to have a current flow of approx 3-4 amps in the primary.

Now if we are discussing a 12 -13 to 1 compression at 8,000 rpm , thats a different story !! But we just dont need it with the flatheads......

[BNewman]

Very interesting and very logical. Thanks.

[flatheadmurre]

Still amazes me why anyone developing a new distributor makes a product that has no advantages over the crab...
If you absolutely wan´t electronic a converted crab is still a better unit...just my 2c.
When someone makes a crab with an adjustable vacuum canister then it´s improving...until then i´m not to impressed...

[BUBBAS IGNITION]

Originally Posted by flatheadmurre

Still amazes me why anyone developing a new distributor makes a product that has no advantages over the crab...
If you absolutely wan´t electronic a converted crab is still a better unit...just my 2c.
When someone makes a crab with an adjustable vacuum canister then it´s improving...until then i´m not to impressed...

"AMEN!!!"

[Phil Gillespie]

Originally Posted by BUBBAS IGNITION

Based on quality and availablility it changes somedays.
Heres the deal on a flathead (low rpm band and low compression) the 12 volt ignition needs a primary current of approx 3-4 amps. A napa IC12SB (1.5 ohms) and a 1.5 ohm resistor would be 3 ohms divided into 12 volts for a current flow of 4 amps. This set up has worked great forever.
Now to step it up just a bit I have been using a German made coil the Beru ZS172 blue at 3.3 ohms and no resistor for a current flow of 3.63 amps , i have shipped over 100 of these and they seem to work very well ! I still like the Bosch Blue # 00012 coil at 3ohms as well, just because it is shipped with a nice mounting bracket..
The main thing is to have a current flow of approx 3-4 amps in the primary.

Now if we are discussing a 12 -13 to 1 compression at 8,000 rpm , thats a different story !! But we just dont need it with the flatheads......

The 3 to 4 amps in the primary side, does this also apply to 6v original coil with resistor?
Phil NZ

[JSeery]

Originally Posted by Phil Gillespie

The 3 to 4 amps in the primary side, does this also apply to 6v original coil with resistor?
Phil NZ

Yes. It is I=V/R, I is the current (Amps), V is the Voltage and R is the resistance (Ohms). The resistance consist of everything in the circuit, but the major components are the resistance of the coil itself and any ballast resistor.

[Phil Gillespie]

Originally Posted by JSeery

Yes. It is I=V/R, I is the current (Amps), V is the Voltage and R is the resistance (Ohms). The resistance consist of everything in the circuit, but the major components are the resistance of the coil itself and any ballast resistor.

Just refreshing my memory on the Ohms Law. So on safe side minimum being 1.5 ohms for the 6v for max 4 amp draw. There is a reason for everything it just a case of remembering!!


Thanks,
Phil NZ

[JSeery]

Yep, the 1.5 ohms in your example is the combination of the coil and any other resistance in the circuit.