90 deg V6 error

[robert dingli]

Earlier I wrote :
> 	
> 	Lastly, someone else asked about the hazards of the wasted spark approach.
> 	I remembered recently where I had heard of problems.  90 degree V6 engines
> 	with only three crank throws fire unevenly 90/150/90/... degrees apart.
> 	The wasted spark may fire while a combustable mixture is present in the
> 	out-of-phase cylinder.   I believe the ignition timing is compromised as
> 	a result.  Perhaps someone experienced with the Delco controlled Buick
> 	3800 V6, as used in local Holden Commodores, may care to comment.
> 

John replied :

> perhaps the holdens are different, but north american buick v6s have
> had split crank throws and even firing since the late '70s - shortly
> after gm bought the tooling back from amc[jeep].

Thanks for setting me straight on this particular engine.  I read about the 
firing order of 90 deg V6s from the little blue Bosch handbook and falsely
assumed that the Holden engine had three crank throws.  Most of the engine
is directly imported from the States and is very similar to the Buick.  I
guess it would be rather stupid in this day and age to use uneven firing
considering the effort place on NVH reduction.

Robert

-- 
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             Robert Dingli           r.dingli at ee.mu.oz.au

Power and Control Systems                 Thermodynamics Research Lab
Electrical Engineering                    Mechanical Engineering
   (+613) 344 7966                           (+613) 344 6728
  University of Melbourne, Parkville, 3052, Victoria, AUSTRALIA
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