Ignition

[vasana]

I'm looking for ways to ignite a carbureted 3.2 motor on an older car.
Thank you.

[PeteKz]

Too little information.

[75 911s]

Yeah need more info, but If I'm picking up what you are laying down, the easiest is an MSD 6AL box, with a nice set of Clewitt wires. Buy the MSD coil and viola, ignition. Plugs on carbs like to be a little hotter with a bigger gap fyi.

[Matt at Pelican Parts]

There's also folks running Megasquirt, Haltech, AEM, and other EFI computers configured only to control spark and remain carbureted. Not the simplest option of course but it has been done a few times

[buster73]

IMO the "ignition 123" distributors are an interesting option. You can adjust your timing to best suit your engine and combine them with almost any ignition system from stock CDI to MSD. Just be sure you order the correct version for your purpose.

[rowingone]

Yes if your distributor needs a rebuild anyway, like mine did . . I went with the 123 ignition distributor and it works great . . is also eliminates the need for a CDI so I bypassed the questionable one in my 1972 911 MFI.

[vasana]

Thank you everyone for the responses. Sorry I didn't give enough information. I have an MSD box and I wonder what I can use for a trigger without using the motronic. The car is a 1974 and the motor is a 1984.

[targa72e]

The 84 3.2 Carrera had a dumb distributor. No advance or trigger mechanicals. It just has a rotor do direct the spark. The ignition advance and trigger is performed by the DME using the sensor that read the flywheel teeth (see picture).



You will need to replace both trigger and advance functions. This is where the 123 distributor suggestion comes in. The 123 distributor would replace your dumb distributor with a distributor that could trigger your MSD and provide ignition advance.

Other options listed are to use some type of programable system to replicate the DME ignition function.
Clewett has a solutions that replace the whole distributor as well.

https://www.clewett.com/index.php?main_page=index&cPath=1_71

lots of different ways to go.

John

[mysocal911]

Originally Posted by targa72e

The 84 3.2 Carrera had a dumb distributor. No advance or trigger mechanicals. It just has a rotor do direct the spark. The ignition advance and trigger is performed by the DME using the sensor that read the flywheel teeth (see picture).



You will need to replace both trigger and advance functions. This is where the 123 distributor suggestion comes in. The 123 distributor would replace your dumb distributor with a distributor that could trigger your MSD and provide ignition advance.

Other options listed are to use some type of programable system to replicate the DME ignition function.
Clewett has a solutions that replace the whole distributor as well.

https://www.clewett.com/index.php?main_page=index&cPath=1_71

lots of different ways to go.

John

Actually, the rotor does move a little as the RPM changes on the 911 3.2, to avoid the spark jumping to the wrong plug wire.

[vasana]

Thanks again. I think 123 is my best option since I have everything else.

[mysocal911]

Originally Posted by vasana

Thanks again. I think 123 is my best option since I have everything else.

Have you verified that the 123 is compatible with a 911 3.2 engine, i.e. CW rotor rotation?

[PeteKz]

Let me make sure: You are NOT running the Motronic system on your 3.2 engine, correct? If so, then the 123 is the best option. It is available with the correct gear for the distributor rotation on SC and Carrera engines

If you are not using the Motronic, what is your induction system?

[mysocal911]

Originally Posted by PeteKz

Let me make sure: You are NOT running the Motronic system on your 3.2 engine, correct? If so, then the 123 is the best option. It is available with the correct gear for the distributor rotation on SC and Carrera engines

If you are not using the Motronic, what is your induction system?

Yes, the spec does indicate this, but has anyone verified this? Also, where's the tach signal to come from?
The only option, i.e. given no tach output on the SC 123, is to convert the a low signal SC/3.2 tach to a coil signal tach.

[PeteKz]

I verified the 123 distributor for SC/Carerra engines with Ian Carpenter. In fact, I'm ordering one myself.

Tach signal: It depends on whether you use a CDI box. The CDI boxes and MSD generate a tach signal. If you go straight from the 123 dizzy output to the coil, I don't know. There are adaptors for tach signals. To get the correct answer, contact Ian Carpenter, "icarp" here. He's tech support for 123 Ignition.

The link to the 123 distributor site:

https://123ignitionusa.com/porsche-3-0-or-3-3-sc-911-or-930-up-to-89-bluetooth-no-hkz/

[mysocal911]

Originally Posted by PeteKz

I verified the 123 distributor for SC/Carerra engines with Ian Carpenter. In fact, I'm ordering one myself.

The acid test is when you personally test it in 911 3.2, with an operational tach.

Originally Posted by PeteKz

Tach signal: It depends on whether you use a CDI box. The CDI boxes and MSD generate a tach signal. If you go straight from the 123 dizzy output to the coil, I don't know. There are adaptors for tach signals. To get the correct answer, contact Ian Carpenter, "icarp" here. He's tech support for 123 Ignition.

The link to the 123 distributor site:

https://123ignitionusa.com/porsche-3-0-or-3-3-sc-911-or-930-up-to-89-bluetooth-no-hkz/

And that's the problem for most. Although, it's a simple add-on with a few resistors and a diode I've designed for some. Using a 123 with a CDI is Mickey Mouse,
i.e. an inductive discharge 123 ignition produces a better spark. Semiconductor technology for ignition systems has improved significantly since the 1970s with CDIs.
It's unfortunate that the 123 doesn't provide a tach output. It would be a simple add-on to the original 123 design.