dizzy 'bout dizzies

[regis101]

Greetings. I only have a bentley as a source of ignition curves. My application is for a stock 78 Westy with a 2.0 hydro engine and stock FI. The zippy-do rebuilt distributor exhibits enough side to side slop that it concerns me. I feel that it is causing erratic timing at idle. I also have a dizzy from a 73 bus/manual trans. It is nice and tight. The bentley does not seem clear enough for me to understand if the curves are close enough that will allow me to swap it over while changing only the vacuum pod from the 78. I could swap over all internals from one to another but am just curious about any difference in curves. Thanks, Regis

[regis101]

I've been reading the bentley again. It's getting clearer. We know that VW was notorious for many curves for their many applications. Here is what I can state. The 205E (73 man.) begins cent. at 1050-1250 rpm. At 2000, it's 13-16 deg. 3600 and it's all in for 23-26. Vacuum on the same begins ( advance side only), at 3.2-4.3 in./Hg and ends at 7.9 in.Hg. for 8-12 deg. So. Easy comparison to my application of a 205S (78 man.). Cent. begins at 1000-1250 rpm. At 1600, it's 8-13 deg. At 3400 it's all in for 20.5-24.5 deg. As for the vacuum, it begins at 3.2-5.1 in./Hg and ends at 7.9 in./Hg for 8.5-11 deg. It is hard to deduce a true comparison because the numbers are not listed at the same rpm. Using my noodle, the curves seem so close. The vacuum side is about dead on. So what should I see or what do you know about the graph of these two centrifugal curves. All I need to be told is that one is slower than the other or it doesn't matter or that FI likes a quicker or slower curve or..... Our Westy runs great and all, but I want to nail down the erratic timing. Maybe get another mpg or something. Thanks, in advance, Regis

[regis101]

Hello. I ordered a Mallory w/vacuum adv for our Westy. Gonna take the two stock distributors to my friends machine shop. He has a distributor machine. I'll make one good one out of the two. Probably spin the new Mallory before installation to get a graph. It can be a comparison/guideline for a back-up stocker. Have to have a back-up, don't 'cha know. And so on.......