Why does my 930 have an SC distributor?
 

My car is in the shop having a few issues dealt with. My mechanic calls me today and asks me if I knew my '79 930 had a SC distributor on it... I did not.

Anyone venture a guess why a previous owner would have done this modification? Should I switch back to a 930 disty?

My mechanic is researching why this might have been done, but I thought I'd ping the board to see if anyone might know...

Thanks,
Skip

Only thing that matters is the ignition curve. Many old cars may have the correct dist internals in the wrong case. The part number on the dist case means nothing.

BD- Good point. But, I think my mechanic believes the curve is wrong... that's how he noticed the distributor was from a 930. I think he said the timing doesn't retard while on boost. But, I am flaunting my ignorance now. :)

Also, I should have stated that I've owned the car since it had 19K miles (currently 26K). I can't imagine needing to replace a distributor (with the correct/same internals) with so little wear. Or, am I missing something?

Thanks,
Skip

maybe the previous owner has some work done at Motormeister ;)

A '79 with 26,000, I do believe you should let me put some miles on the clock to make sure no other parts in question. Just an offer.

A stock 930 dist doesn't retard on boost. It retards on vacume. So I am guessing that you have the correct dist. You might need a new mechanic though.

No, it's probably just me. I remember the mechanic was talking about vacume, but (in my mind) I saw it as retarding "for" the boost... to reduce a lean condition... I think...

Timing and ignition is a big fat freakin mystery to me. I understand conceptually how energy gets to the plugs, and how the energy is created and what the energy is used for (spark) - but past that... :confused:

Thanks for the clarification.

- Skip

:) I'm working on it... It's been moved to daily driver status...