Bosch vaccum cannister interchangeability, can you swap between dizzies? Options

[bbrock]

I rebuilt my Bosch 2.0L dizzy (p/n 039 905 205) but the vacuum canister is bad so I used a good one from a 1.7L dizzy I have on hand. The PET lists these as different part numbers and now I'm wondering if I need to track down the correct canister for this dizzy. Anyone know how much difference in advance between canisters and if it will make a difference? I'm going to be running Webers for now but may eventually restore the D-Jet and install.

[bbrock]

@porschetub , you are correct. The PET lists seven different part numbers for dizzies and five different part numbers for vacuum canisters. Dizzies that came with a rev limiting rotor got a different p/n from one that had a regular rotor so that is part of the alphabet soup.

All of the dizzy numbers end with 205 and in his Weber book, Tomlinsons recommends the "205" distributor but doesn't specify a particular version. The 1.8L dizzy is 022 905 205 S which does appear to only be used on that engine.

I found some answers in the Tech/Spec book (see below). It looks like the 1.7L vacuum canister should work fine on the 2.0L dizzy as they are essentially the same. The difference is that the 2.0L canister has an adjustment screw that allows some adjustment of the advance and retard where the 1.7L is statically set near the midpoints of the 2.0L adjustment range.

For advance curves, it looks like the 1.8L advance kicks in later (both mechanical and vacuum) than my 2.0L dizzy and provides a few degrees more advance through the curve and considerably more total advance. I don't understand this stuff very well but suspect that means the 1.8L dizzy would potentially make more HP at WOT and maybe stronger pull?