Anyone running 123 Distributor on a 3.0

[Dpmulvan]

Thought about putting one on a 3.0 anyone running one? Any issues?

[brp914]

I have one in a 3.2 with PMO. It was installed at a shop. No problems with it after a couple years. Apparently, it's timed via bluetooth.

[snbush67]

There is an issue with oil creeping up the distributor shaft. The US 123 provider now has an option to order with a spiral groove in the shaft that prevents oil from pushing up due to crankcase pressure.

The locking collar has to be tightened to its maximum. It’s important that once the distributor is positioned, then remove the distributor and torque the collar bolt, then reinstall in the same position. If the collar isn’t tight the shaft can move up and can damage the cranks distributor drive gear.

The drive gear is slightly smaller than the stock gear. It may contribute to wear on the crank distributor gear.

My experience with the MSD is a noticeable increase in power 5-7%.

The Bluetooth option allows the ability to tune ‘on the fly’ while the car is in operation, combined with an AFR gauge it is extremely valuable as a tuning tool. You can tune anywhere along the curve to within .5 degrees.

Users can also add vacuum from below the throttle plate to add a MAP curve.

[Dpmulvan]

Did not know about the spiral groove option, thanks for the input.

[snbush67]

I replaced the 123 cap clips with the stock cap clips, they hold the cap tighter and don’t deform.

You can see the stock clips in the photos below and also the orientation of the distributor that I prefer.

Also, the collar gets positioned as high up as it can go, this places the gear in the same position as the stock distributor.

[Henry Schmidt]

We like them so well that we are using them as the base/core of our twin plug conversions.
We couple these twin plug conversions with the the Supertec Twin CDI or for a more original look, the Ashlock Dual CDI.

[fabracadabra]

That is a nice looking solution, where can I read more about the supertec twin plugging with the bluetooth distributor?

[icarp]

Henry, is that two bluetooth plates for spark inside the distributor? Allowing for a twin plug 911.
123 has determined that the use of twin bluetooth plates will result in corruption of the programed curve. Mittle motor still sells a similar product and I have never seen one work well.
Maybe one day 123 will build a 12 plug plate for the 911 crowed .

As it stands now I do not know of any, that work well, are for sale

If I recall correctly Bob Ashlock was working on an idea to use a single signal to ignite two plugs

[Henry Schmidt]

Originally Posted by icarp

Henry, is that two bluetooth plates for spark inside the distributor? Allowing for a twin plug 911.
123 has determined that the use of twin bluetooth plates will result in corruption of the programed curve. Mittle motor still sells a similar product and I have never seen one work well.
Maybe one day 123 will build a 12 plug plate for the 911 crowed .

As it stands now I do not know of any, that work well, are for sale

If I recall correctly Bob Ashlock was working on an idea to use a single signal to ignite two plugs

I'm not certain what you're talking about. Single trigger distributors have been operating twin plug applications for 40 years.
Splitting the signal is not generally a disqualifying or functionally inefficient system.
Please clarify the concerns you have and explain the physics.
Thank you.

On a side note: US 123 Distributors and Permatune are anxious to market this product.

[snbush67]

Henry, I think I understand, the 123 signals the dual CDI to trigger the coils, the 2 coils simultaneously charge the rotor, which then fires at a single distributor pole (which is attached to two plug wires) and spark the 2 upper and lower plugs of the same cylinder.

Is there any cause for concern that each plug isn’t getting its own direct charge? Do you know if each plug is getting an equal spark? Or is it random? Does it even matter?

[Henry Schmidt]

Originally Posted by snbush67

Henry, I think I understand, the 123 signals the dual CDI to trigger the coils, the 2 coils simultaneously charge the rotor, which then fires at a single distributor pole (which is attached to two plug wires) and spark the 2 upper and lower plugs of the same cylinder.

Is there any cause for concern that each plug isn’t getting its own direct charge? Do you know if each plug is getting an equal spark? Or is it random? Does it even matter?

Some clarity from someone who knows

Bob @ AshlockTech
A simple distributor with a set of points can’t fire two coils.
A couple of things go wrong … first, twice the current flows through the points when they are closed. Normal current when closed with one 2 Ohm coil may be as much as 6A. Double that and you are now at 12A. This will toast them pretty quickly. Second, in that instant of time when the points “open”, the primary winding current in each coil collapses resulting in a higher voltage that gets stepped up to the wanted 30KV high voltage spark in the secondary. Trouble is with the coils primaries still connected together, they don’t behave exactly the same. Instead of releasing all that stored energy as a spark, some of the primary current ‘circulates’ back and forth between the two coils. So you get two weaker sparks (maybe) or you might only get one coil to spark but not the other.

All these same things apply with a common 123 distributor. Instead of physical points, it just has a transistor doing the points function. So the behavior is the same. So, for twin plug applications, the 123 actually has to use TWO independent circuits inside, each firing its respective coil.

When two CDI units are used, it is a different story. The points, (or the electronic switch/transistor in the 123) only provide a trigger signal to the CDI boxes. The CDI trigger circuit presents a very light load to the distributor. A Bosch box trigger demands no more than 0.4A of current. So no loading problem with multiple CDIs. And the CDIs trigger just fine and do not care that another one next door might also be getting triggered. There is no ‘circulation’ between the trigger circuits. Each CDI dumps its 400V charged capacitor into its respective coil.

[Turbo_pro]

Great information Henry.
Are you comfortable with the electronics in the 123 given the high vibration environment of the 911 engine?
Are you still modifying SC/930 distributors for twin plug?

[E Sully]

Originally Posted by snbush67

There is an issue with oil creeping up the distributor shaft. The US 123 provider now has an option to order with a spiral groove in the shaft that prevents oil from pushing up due to crankcase pressure.

The locking collar has to be tightened to its maximum. It’s important that once the distributor is positioned, then remove the distributor and torque the collar bolt, then reinstall in the same position. If the collar isn’t tight the shaft can move up and can damage the cranks distributor drive gear.

The drive gear is slightly smaller than the stock gear. It may contribute to wear on the crank distributor gear.

My experience with the MSD is a noticeable increase in power 5-7%.

The Bluetooth option allows the ability to tune ‘on the fly’ while the car is in operation, combined with an AFR gauge it is extremely valuable as a tuning tool. You can tune anywhere along the curve to within .5 degrees.

Users can also add vacuum from below the throttle plate to add a MAP curve.

I have done a little work on '72 '73 '77 and '86 distributors. The Bosh distributors have lubricating felt (13) between the bushings (11-12).

While the early ones all had a smooth shaft the '86 has a reverse thread spiral groove. I thought it was for some lubrication purpose. I've also seen the groove in the shaft of an '83 SC in another thread.

[snbush67]

Originally Posted by E Sully

I have done a little work on '72 '73 '77 and '86 distributors. The Bosh distributors have lubricating felt (13) between the bushings (11-12).
While the early ones all had a smooth shaft the '86 has a reverse thread spiral groove. I thought it was for some lubrication purpose. I've also seen the groove in the shaft of an '83 SC in another thread.

My 78 shaft had a reverse spiral groove as well, I don’t know when Porsche started that but it seems it is needed on most cars.

[snbush67]

Originally Posted by Henry Schmidt

Some clarity from someone who knows

Thanks for sharing Henry.

[Henry Schmidt]

Originally Posted by Turbo_pro

Great information Henry.
Are you comfortable with the electronics in the 123 given the high vibration environment of the 911 engine?
Are you still modifying SC/930 distributors for twin plug?

1) the "high vibration environment" of the 911 engine does present some concern.
I guess only time will tell.
2) yes, we still convert Bosch distributors to twin plug but only when absolutely necessary.


I believe that spiral tread mechanism is called an Archimedes' screw.
They work as a rudimentary pump that has been used to move fluids since before Christ.

[Old H2S]

I got mine in 2018 and flog it hard. No problems yet? I keep asking how long do they last and no one knows. A few have failed but at random times so no solid life time yet. Thank you Shane for your data.. my gas milage is way up.

[Dpmulvan]

How are you guys with modified engines setting advance curves?

[Old H2S]

Start with the info from Porsche on centrifugal and vacuum curves and then get the co-driver to play with numbers as you drive.

[snbush67]

Originally Posted by Dpmulvan

How are you guys with modified engines setting advance curves?

Setting a curve is simple with the 123. I am able to get within 98% of perfect tuning using a 123, an AFR gauge and reading spark plugs.