Turbo header design

[Jemison Richard]

I don't know the in's and out's of this 180 degree situation but as a frame
of reference, the Saturns use a 180 degree crank, 2 coils, fire 2 injectors
at a time, etc.  Runs dead smooth.  

Rick

> -----Original Message-----
> From:	Clarence L.Snyder [SMTP:clare.snyder.on.ca at ibm.net]
> Sent:	Friday, January 08, 1999 1:56 AM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: Turbo header design
> 
> Greg Hermann wrote:
> > 
> > >
> > >    Care to elaborate on this a little? Are we talking about crank
> vibration
> > >(hamonic balancer/flywheel) or something else over my head? Also, a
> Chevy
> > >V-8 fires every 90 degrees of crank rotation. How does a flat crank V-8
> > >fire? Every 180 degrees would make sense, but then it would take 4
> turns of
> > >the crank to hit all 8?! I am so confused......
> > 
> > Secondary vibration, due to the fact that piston accelerations are
> > different at the top and bottom of the stroke due to con rod angularity.
> A
> > four cylinder has an up and down shafing force at twice crank speed
> (which
> > is sometimes countered fairly well with two "balance shafts" counter
> > rotating at twice crank speed.) A flat crank V-8 is like two fours.  Too
> > late at night to try to describe the shaking which results. 
> 
> The well known "big four buzz" common to modified Ford "B"s, Vauxhaul
> 2300s, and ford 2300s, as well as the Vegas (ouch!!) My '28 Chevy
> National and Vauxhaul HC 2300 twin-carb both buzzed pretty good. Hard to
> immagine two of them out of phase!!