V-8 Int. man. design

[Gary Derian]

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> From: Paul (BRAAP) Ruschman <prusch at ix.netcom.com>
> To: diy_efi at coulomb.eng.ohio-state.edu
> Subject: V-8 Int. man. design
> Date: Tuesday, 27 May, 1997 1:44 AM
> 
> I am new to the list and am currently designing my own EFi Intake 
> manifold for my Chev 350 powered Datsun Z car. I plan on using the 
> L-jetronic.
> 	My question.
> 	My plan is to make a manifold that utilizes two plenums, one per 
> bank of cylinders. Knowing that the V-8 fires as if it were 4 V-twins 
> stacked instead of two banks of four cylinder engines does this effect 
> the intake air flow to the individual cylinders? Do I need to design the 
> intake like a dual plane 180 degree carb manifold that plenums the two 
> outer cylinders of one bank with the inner two cylinders of the other 
> bank?
> 	I feel that this being injected that it shouldn't make much 
> difference fuel wise, but would one cylinder rob the available air the 
> next cylinder is supposed to recieve?
> 
> 		Thank You,
> 	Paul (BRAAP) Ruschman
> 	http://www.datsuns.com/paul.htm
> 	http://www.datsuns.com

Uneven pulsation will affect the intake flow and the averaging that the air
flow sensor sees.  Use two plenums but not for one bank only.  Instead,
connect cylinders 1, 4, 6 and 7 to one plenum and 8, 3, 5, and 2 to the
other.  This will make each intake stroke at 180 degree intervals and
provide balanced flow.  For best performance, the exhaust should also be
connected this way but the gains are small.
Gary Derian <gderian at cybergate.net>