CDI's in Oz

[Mike Morrin]

At 08:25 AM 21/05/98 -0700, garfield at pilgrimhouse.com wrote:
>On Thu, 21 May 1998 20:23:03 +1200, Mike Morrin <mikem at southern.co.nz>
>wrote:
>
>>I wouldn't recommend any CDI for a modern 4 cycle engine.
>
>Ehh? Wow, what about the SAAB system we've been discussing, which has
>been in the field with nary a single design change, since '92?
>
>Whadamy missin here, Mike?
>
I must learn not to make throwaway comments...

Just the reason of CDI sparks being too fast for lean burning motors.
Typically causing a light throttle misfire. 

CDI apparently needs either a rich mixture, or a combustion chamber design
which ensures that there is plenty of gas near the spark gap at the time of
ignition.

I don't know whether Saab have a way of stretching the spark (the DSE kit
doesn't), or if they just have an engine design which tolerates short spark
duration.

regards,
Mike Morrin