On my car (almost certainly the same as yours) Z1 is TDC, and the other mark, to the right, is 5 degrees BTDC. When I rev my engine, timing moves clockwise. I think. No way to check it right now, since the heads and cylinders are in Seattle.

And yes, now that you mention it, I may not need to remove my pulley and use a protractor to make a 25-degree mark. Since 5x5=25.

does your clock run backwards? i've seen those.

SM - that's a pretty good idea. The only part about a dizzy rebuild that I'm nervous about is having those little advance springs go SPROINGGGGG, and I never find them again, or I can't get them back on again correctly. I know the centrifical advance works, so attacking just the vacuum problem would be a quick solution.

Olivier,

I think you are correct. As you rev up the engine the timing moves from 5 BTDC to 20 BTDC (give or take). Thus, the Z1 mark appears to move counter-clockwise.

PS the two marks on mine are at TDC and 5 ATDC (not 5 BTDC), but mine was built rather late in the run

Jesus John, you've aged most gracefully...and look an awful lot like, well, oh nevermind...

John

PS: <overheard at Dead show> "Jerry, I'm spinning...help me Jerry I'm SPINNING!!"

Bill, I think you have the right spirit. You can remove the distributor and drill out the soft pin. This will enable you to remove the guts and shaft from the housing. This gets you access to all the guts. You may decide not to disassemble the centrifugal advance since it will be easy to see and not impossible to clean and lube without disassembly.

You might even want to make it simpler. first (before removing the distributor), try to remove the vacuum advance unit. If it comes off easily, then it was not hooked up inside the distributor, and you will have found your problem. If it holds a vacuum then repair will be as simple as reconnecting it to the guts of the distributor. This might require removal of the distributor, but through the vacuum advance hole you can also probabaly clean up the weights without taking the shaft and guts out of the housing.

Gosh, just take the distributor out and take the vacuum advance off. If it is holding vacuum but not working, I suspect it has come dislodged from the plate (in the guts). This would probably take John Walker three minutes to fix, and another five to reinstall and re-set timing. It would take Superman about 3 days, but that's because I seem to work in about 2-minute spurts these days.

Graham,

Is your 5 ATDC mark to the left of Z1, then?

Olivier

Olivier,

Yes it is to the left of the Z1 mark. Not terribly useful.

it depends on the year of your model ; my car is supposed to be timed at 5 ATDC, so the 2nd mark is on the left of Z1; if yours has to be 5° BTDC (most of 911s), the mark is on the right... and as a matter of fact, I have a 25° advance mark (clockwise from Z1)...

Who can tell me why SC distributors turn counterclockwise, whereas mine (and 3.2, I think) turn clockwise? is there one more pinion?

...pictures of the 5° ATDC and Z1 notches, and the same during the dynamic timing ..
http://www.pelicanparts.com/ultimate...ds/z1_zoom.jpg
http://www.pelicanparts.com/ultimate...age_avance.jpg