Timing belt ?

[Huw Powell]

>> You could run the dizzy off the crankshaft, but then there'd be a 
>> wasted spark at TDC on the exhaust stroke.  And coil charging time 
>> would be halved...
> 
> 
> Some cars (the Miata comes to mind) have a wasted-spark by design.
> I think 1 coil powers 2 spark plugs, so one spark gets wasted each
> (every other?) cycle.

Yes, wasted spark itself is not really a problem - halving the coil 
charge time could be.  In examples like the one you give, the coil has 
longer to charge, since there is one for each pair of cylinders instead 
of one for all of them.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/