Ancient History, and Djet and cams

[Robert J. Harris]

Remember the Reichstag

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> From: RD Rick <rickydik at ix.netcom.com>
> To: diy_efi at coulomb.eng.ohio-state.edu
> Subject: Re: Ancient History, and Djet and cams
> Date: Monday, September 02, 1996 10:42 PM
> 
> Correcting myself here:  fuel squirts at beginning of intake stroke on 
> two cyl, and beginning of exhaust stroke on the other two.  
> Note: injector duration at Op Temp, WOT, 6,000 rpm, is 8.3 ms, while 
> the valve is open only 5 ms.
> 

Note for the timed/untimed discussion - the injector is pushing fuel for
far longer
than the valve is open.  At this point, the question is moot.  To have
enough
fuel to make power in this region, it must store fuel by puddling it on the
valve and waiting for the inrush of air to finish mixing it.  When it
stores it 
there is of no consequence.

The closer to the cylinder the fuel is injected the less the mixture
problems.
Sequential port fuel injection kicks butt over throttle body primarily
because
it generates a higher quality mixture that is more closely tuned to the
engine.
It starts with an unfair advantage because it eliminates all the
complications
and compromises of moving a gas/liquid mixture thru plumbing and instead
deals with an air only system.

Enough about timing - anyway works - get the mixture right and run.  Take
maximum advantage of the mechanical properties that you can. Leaves 
less for the control system to solve. GMC roots mechanical positive 
displacement 6-71 superchargers make monsterous horsepower yet the 
whole high pressure fuel air charge comes out of the blower totally 
asynchronous with regard to valve openings and cylinder filling
and it has worked very well for 40 years of racing and street!!!!!.