Should I machine down a late model distributor for my 2.2T?

[BlueSideUp]

Currently I have an early Bosch distributor PN 0 231 159 001 in my 2.2T. The curve isn't correct for a 2.2 based on what has been posted in other threads by john_cramer and early_S_man.

Here's one from john_cramer's thread showing the 001 curve...



This is the later model E and S curve...



Here is the 2.4T curve...



I can't find a 2.2T curve but I have found a 2.4T distributor. From what I've read the 2.4 distributors need to be turned down from a 30mm body to a 28mm body to fit in the 2.2. Ideally I'd like to find a Bosch 2.2T distributor but that seems to be like finding hen's teeth.

I am going to rebuild my early 001 distributor with new parts and sell it once I find a proper distributor for my car. At this point I've been searching and reading about installing Pertronix in my current distributor vs. new points.

[911pcars]

What is sometimes confusing is that PAG created these charts with two similar data points; either distributor degrees of advance or crankshaft degrees of advance. Dist. degrees are 1/2 engine or crank degrees. Because of this, the charts seem different.

In addition, the static timing has an effect on the total advance. Compare an engine with initial timing of 10º BTDC and an engine set at 0º or even ATDC. Combine these static timing settings with the distributor curves and you'll see the overall total ignition timing, while not the same, is quite similar.

For example, let's compare the 001, 006/007 and 2.4 distributors at 2000 engine rpm:

001: chart is in dist. rpm and dist. degrees.
2000 engine rpm = 1000 dist. rpm on chart; the dist. advance is 7º dist. or 14º engine

006/007 is the same

2.4 dist.: chart is in engine rpm and crank degrees
2000 rpm = 20º crank advance.

If the initial timing for 001, 006 or 007 is 5º BTDC, total ignition advance is 19º at 2000 rpm.

If the initial timing for 2.4 dist. is 0º or TDC, total ignition advance is 20º at 2000 rpm.

Thus, max. crank advance for all charts is ~32-34º BTDC.

Check the factory specs for static ignition timing to confirm real numbers

Sherwood

[911pcars]

To add to any confusion, here are some more curves:









Sherwood

[Fishcop]

I did this mod a few years back, definitely one of the best things I did...

Converted Distributor (Late Bosch 2.7 to replace Marelli)
Marelli to Bosch Conversion (Pics)

[Tar356]

John...

I may have missed it in the thread, but how did you deal with the vacuum canister?

Thanks,

Todd