1968 911 Targa 2litre

[goodguy9]

Hi Guys,
Who makes the best electronic ignition set up for my 68 911 targa please?
It is time to upgrade from points...
I have both distributor types..

[304065]

WELCOME to the forum!

Opinions, occasionally passionate ones, abound on this topic, but I am a big fan of the original Bosch CDI.

I would use the Bosch distributor and save the Marelli for show. You can mount the CDI unit up in front of the air cleaner for an original look and hide the wires in the harness for the alternator, and then use a BLACK CDI-type Bosch coil in place of the Kettering-igntion coil over on the electrical console. Or if you can't find that, a Bosch Blue coil will not hurt things.

The great thing about the CDI is that you actually KEEP the original Bosch points. Setting the gap is easy with a feeler gauge, and the CDI is MUCH less sensitive to dwell. With Kettering-ignition, when the points are closed (the "dwell period") the magnetic field builds up in the coil and then breaks down when the points open, creating a spark. The faster the engine runs, the less time there is for the field to build up and break down, which is why having the exact dwell is so important.

The Bosch CDI, on the other hand, charges its capacitor in about a microsecond with the points closed, then when they open, dumps a 460 volt pulse into the "transformer" style coil which gives you the spark. Elegant.

Don't worry about the points wearing out, the current in the circuit from points to CDI trigger is only 420mA, they will last a VERY long time.

Now, you say, "Why not a hall-effect or optical ignition trigger?" To which I say, they don't really help unless you are completely incapable of adjusting the points correctly, and the big trouble is, they are impossible to diagnose. Points are easy, you check the gap, look at the contact, put the dwell meter on. How does one test whether one's Pertronix is working in a rainstorm at roadside when one has been compelled to "get out and get under?" Only nerds like me drive around with a portable oscilloscope in the trunk.

Anyway, that's my not-so-passionate opinion on the subject. For some fun pictures check this thread:

Before there was BHKZ: SWB engine electrics

And GOOD LUCK!

[rvanderpyl]

I had a Marelli which was worn out so I bought a later 2.7 distributor and had the shaft reworked to fit my 2.2, then I installed one of the Crane Optical Ignitions. Worked great. Sold it to a fellow Pelican who also had a worn Marelli and he loves it.

[Henry Schmidt]

Supertec makes a pointless distributor that uses 911SC style internals.
The 911SC 6 pin CD and 911SC cap and rotor.
They are built with a custom curve to suit any engine application.

The larger cap is especially beneficial at higher rpm.

With this and any other part, we suggest you ask our host, Pelican Parts to see if they have what you need before contacting us.

[jasam]

Originally posted by john_cramer
WELCOME to the forum!

Opinions, occasionally passionate ones, abound on this topic, but I am a big fan of the original Bosch CDI.

I would use the Bosch distributor and save the Marelli for show. You can mount the CDI unit up in front of the air cleaner for an original look and hide the wires in the harness for the alternator, and then use a BLACK CDI-type Bosch coil in place of the Kettering-igntion coil over on the electrical console. Or if you can't find that, a Bosch Blue coil will not hurt things.

Is there any problems fitting a 2.4 BOSCH dist or maybe a 2.7? doesn't matter the year and the engine? I'd like to keep the marelli as you said for some shows

[304065]

The shaft diameter of the 2,4 and later is larger than the 2,0-2,2.

[jasam]

Originally posted by john_cramer
The shaft diameter of the 2,4 and later is larger than the 2,0-2,2.

so I must buy 2.0 or 2.2 BOSCH dist?

[Henry Schmidt]

Shaft diameter for the 2.0-2.2 is 27 mm. The shaft diameter for all later 911 engines is 30 mm.
In the past we have, during rebuilds turned the shaft on a 30 mm distributor down to 27 mm to make it work in a 2.0-2.2 case.
I.E. install a 2.7 (001) distributor in a 2.2 mag case to get rid of the Marelli distributor.
The modification requires recurving but it does work.
It also makes sense to install a point replacement system (pointless) like Pertronix at the same time.

[jasam]

Do you have any pictures of the process?, so it's okay If I buy a 2.4 BOSCH and then modify the shaft?