<VV> Ignition timing question.

[Sethracer at aol.com]

In a message dated 8/29/2005 6:55:02 PM Pacific Daylight Time,  
pottsf at msn.com writes:

How can  IGNITION timing make it harder to crank an engine. If IGNITION is
affecting  cranking, then the fuel-air mixture is igniting, and the engine is
RUNNING.  Am I missing something?

Joe Potts



Yes, experience! <grin> I guess it is because of the point of  ignition, but 
cranking becomes very hard when too much initial advance is  applied. I think 
that the firings during cranking, if they occur  much before TDC (which they 
will while cranking) will cause cylinder  pressure to rise before the engine 
reaches TDC - working (pushing  back) against the starter motor. Another option 
on race cars is to engage  the starter separately from the ignition, get the 
motor cranking, then turn on  the ignition. A byproduct of this one is great 
flaming pops out the exhaust, as  well!  - Seth