[Walt Fricke]

Well, this is interesting.

However, my SC's distributor has vacuum ports on both sides of the vacuum diaphragm, so it can both pull and push, can't it? I'd always wondered about that until a guy here had trouble with his leaking and cut it apart and we could see why a seal around the actuating connector wasn't needed.

And a few degrees of movement of the cap wouldn't make any difference in spark timing or intensity, would it? The cap posts inside at the rotor are what - maybe 5 or more degrees wide? And the end of the rotor maybe three times that?

Although compatibility is needed, isn't the advance determined by (other than by the ECU) the rotation (centrifugal and vacuum) due to where the points or reluctor bits are? And change in position at firing of the rotor itself kind of immaterial?

In designing an in-car cam measurement system using a replacement cap, my 944 friends warned me that the 944 cap retention system was rather loose rotationally, and they said it didn't need to be tight because the ECU did the timing and the rotor tip system was broad enough to handle the entire advance/retard range there.

I had supposed the post style terminals allowed an electrical/mechanical connection which was better (more like most spark plug connections) than the older push in system.

Speaking of plugs - are they all still designed with a male screw tip, and a female screw on wasp waist piece? Why not just the wasp waist part integral with the plug? Are there motors which still use a ring connector these days? Some motorcycles? One NGK plug I favored came without the screw on piece (purchased from a motorcycle shop), so I always had to take off the old screw on parts and reuse them.