2.0 Distributor Discussion

[dmaddox]

Hello - Upon investigating a starting issue I've been having, I have been going through fuel delivery and ignition to clean/diagnose/etc.. each system.

Upon doing so, I discovered that my early 1968 2.0 (911L) contains a 70/71 2.2 Bosch distributor (0 231 159 008). While the original/correct distributor is 0 231 159 001, the car seems to be running ok once started, with an acceptable power band (although I have yet to really warm up the car and get it into the higher RPM range).

In researching the advance of these two distributors (the 001 and the 008) I found the following:

008
10 degrees advanced at 1000rpm
12 degrees at 1500
14 degrees at 2000
16 degrees at 2500
19 degrees at 3000

001
7.5 degrees advanced at 1000rpm
8 degrees at 1500
8 degrees at 2000
10 degrees at 2500
13 degrees at 3000
15 degrees at 3500

These two distributors advance on very different curves. Using http://www.sparkingplugs.com/9.html as a resource, I noted this rather interesting statement:

"Porsche matched distributors to engine and model type as shown in the table below. Some degree of crossover is possible, as is some 'tuning' of the advance curve. But hard limits and transitions are determined by the design of the advance mechanism and are difficult to modify. In most cases, the distributor designed for a particular Porsche model is the best choice."

Now, unless modifications have been done to the 008 that is in my 2.0, I have been running on a 70-71 911T advance curve. Looking at the charts on the website, along with the analysis I posted above, would you expect a degradation in performance going back to the 001, which was intended for the 2.0?

Maybe I am fussing over nothing here, but when others are fussing about the correct "BOSCH" orange in the replacement lens, I don't feel so bad digging into the specifics of a distributor.

Again, I am learning and appreciate any guidance.

Cheers.

[Jerry L]

The dist curve differences are based mostly on the cams & cam timing mated to the different compression of the models and "as factory built" now 50 years later many may not know what is really in your T, E or S. If you do know your build specs you could match that to the closest stock distributor. Now also factor in the selected distributor may not be performing / giving you the curve as displayed.
Bruce Smith of SparkingPlugs is a great and very talented guy, he can assure your distributor is performing as it should as well as match it to what ever curve that you think matches your motor if it has had a rebuild as most have had at this point in life. Give him a call to discuss your particular situation, I am sure you will be happy with the outcome.
BTW I am running a Bosch 007 in my 71 T due to the build after removing a Marelli that had worn advanced weights.

Best Regards

[dmaddox]

Thank you Jerry L. Once I get my car setup with the 001 distributor that it came with, I will ensure the advance at each RPM matches or is within the "band" of the factory advance curve for the distributor. If not, will have to dive in.