Ignition options for backdated 3.2

dpetteng · 09-08-2021, 12:27 PM

So I have a 1985 3.2 engine that has been rebuilt by Neil Bainbridge with PMO carbs. Looking to run with a distributor and no ECU but possibly a cdi.

This will be running on a rebuilt 915 and all fitted to a 1971 VW camper van running Porsche brakes.

Looking for a sensible ignition setup without going modern crank trigger. What are my options for distributor?

snbush67 · snbush67's Garage

123. No CDI required. Tuneable curve by Bluetooth.

Easy as pie, but pricey. 800$ ish with the coil.

https://123ignitionusa.com/porsche-911-bt-tune-2-4-2-7-3-3-1972-and-up-works-with-or-w-o-3-pin-hkz-not-6-pin-bluetooth-programmable/

Flat6pac · 09-08-2021, 03:40 PM

2.7 distributor, 3 prong CD, 001 coil, CD wire harness
Bruce

dpetteng · 09-09-2021, 04:45 AM

Do I need to LH cog if I got for the 2.7 distributor?

Flat6pac · 09-09-2021, 05:32 AM

2.7 and 3.2 distributors both rotate clockwise
Bruce

dpetteng · 09-10-2021, 01:40 AM

Quote:

Originally Posted by Flat6pac

2.7 and 3.2 distributors both rotate clockwise
Bruce

Thanks so much, so I will get hold of a 2.7 dizi. I have had bad experiences with the 1-2-3 dizi.

faapgar · 09-10-2021, 05:56 AM

Heads up.Using a 2.7 distributor works but the teeth backlash is greater.You should swap the gear from your 3.2 for proper fitment.With the increased backlash the brass drive gear on the crank will suffer.Fred

911 SLANT · 911 SLANT's Garage

What were your bad experiences with 123 distributor. I was planning on buying the Bluetooth programmable.

911 SLANT · 911 SLANT's Garage

Pmd you

icarp · icarp's Garage

I am a fan of the 123 line , although I have received one defective unit but Ed took care of that .
Ford based and 911 engines love the 123 bluetooth system.
Please post the problem with the 123
Thanks
Ian

dpetteng · 09-15-2021, 01:36 AM

The problems I had with the 1-2-3 were related to my POrsche 356b. I still have it on 6v wiring and the 1-2-3 is supposed to work on 6v but consistently had problems with voltage drop. I replaced with a standard dizi and problems went away. May be unfair to judge based on that and I will think about the 1-2-3 for my 911 project.

SO with the 1-2-3 you don't need a CDI unit?

snbush67 · snbush67's Garage

Quote:

Originally Posted by dpetteng

The problems I had with the 1-2-3 were related to my POrsche 356b. I still have it on 6v wiring and the 1-2-3 is supposed to work on 6v but consistently had problems with voltage drop. I replaced with a standard dizi and problems went away. May be unfair to judge based on that and I will think about the 1-2-3 for my 911 project.

SO with the 1-2-3 you don't need a CDI unit?

No, you don’t need the CDI, it’s all in the distributor.

icarp · icarp's Garage

Thanks for the info on your 123, It is a good idea to add a voltage stabilizer in the 356 line with 6v systems . The 911, 123 works with just a coil , or cdi you need to pick the way you want to go .
If you choose the CDI you have to stay with it , if you choose coil or MSD then you have to sitck with it .
I love the bluetooth feature , I make a custom curve for each engine
I hope this helps
Ian

dpetteng · 09-16-2021, 01:47 AM

Wonderful, I'm convinced! I love he idea of mapping curves and being able to remotely disable the vehicle. I also love not having to buy a CDI+ unit as well as a distributor.

So the thread above talks about needing to use a 3.2 distributor gear to mesh properly with the crank gear but on the 1-2-3 site it has the same gear for 2.7 and 3.3 (3.2?) What do I actually need to buy?

icarp · icarp's Garage

The drive that comes with the 123 works with all my engines , it is like the 3.2 gear
If you want you can just go with the coil only option, that is upgradable to the msd box
the other option is the 6 pin CDI , that is for the CDI only
When I buy the coil only version I have them include the coil with the purchase .
Have fun
Ian

dpetteng · 09-16-2021, 11:01 AM

Simplicity is the key for me so distributor and coil sounds the way to go. Thankyou

AndrewCologne · AndrewCologne's Garage

123 itself is just a distributor – regarding the spark, if just using a 123 dizzy the spark will be "generated" by the Coil like in the early years.
The benefit of a CDI unit like Bosch or other brands is that they provide a high voltage spike with approx 400v volts where a Coil "transforms" that spike x100 up to 40.000 volts and here is the benefit.
So if using the 123 dizzy I would at least combine it with their "Big Fat Spark" unit for spark enhancement with the proper "transforming" coil like used with a CDI.

I would go the way Bruce suggests, ... 2.7 or 3.2 distributor, 3 pin CDI, 001 coil and CDI wire harness ... reliable and .... a classic coeval genuine like solution.

dpetteng · 09-17-2021, 01:32 AM

Ah ok, I didnt realise you get a bigger spark with a CDI, food for thought!

icarp · icarp's Garage

If you choose the 123 for the coil you can switch to the MSD box when you can afford the upgrade
I doubt you will notice the difference. Good coil, new wires not berue , cap , rotor, new plugs ,
This makes a big difference . You are more apt to feel the timing curve.
There are many debates on CDI vs MSD. neither is wrong .
Have fun
Ian

Henry Schmidt · Henry Schmidt's Garage

Supertec makes a distributor that runs an SC style, Bosch mag pulse ignition.
Uses any six-pin CD or MSD ignition.
Best option we've seen so far.
It even uses the stock 3.2 rotor, cap and wires.
It can also use an SC car and rev-limiting rotor if desired.
Looks correct, RS advance curve and reasonably priced.