All us old drag racers only know one throttle position WFO. right Bruce.
Glen
----- Original Message -----
From: "Ed Lutz" <edlutz@laverdajota.com>
To: "LSR List" <land-speed@autox.team.net>
Sent: Monday, April 29, 2002 4:01 PM
Subject: Re[2]: Fuel Injection
> This is interesting, I had no idea those mechanical injection systems
> were continuous flow. Strikes me as a nasty way to deal with part
> throttle fuel metering. How about closed throttle on overrun? Do
> they still flow fuel? This would cause a very rich mixture when you
> crack open the throttle again.
> As a matter of interest, the mechanical fuel injection used on Alfa
> Romeo cars in the USA up until the mid 80s I think, has systems to
> compensate for engine temperature, barometric pressure and throttle
> position, plus its fully timed. Its quite a nice little piece of
> mechanical engineering. Not as accurate or easy to set up as a good EFI
> system but it works amazingly well for something that was first
> released in the early '70s.
>
> Ed
>
> Monday, April 29, 2002, 11:37:41 AM, you wrote:
>
> AN> Dick;
>
> AN> A continuous- flow FI system such as the Hilborn, Crower, Kinsler,
Algon,
> AN> etc., simply sprays fuel continuously from each injection nozzle. The
amount
> AN> of fuel delivered depends on the injector orifice size and fuel
pressure.
> AN> The fuel pressure is controlled by a barrel valve that is opened &
closed by
> AN> the throttle position. There are also other controls such as fuel
return
> AN> jets, etc. that allow the fuel delivery curve to be tailored to the
engine's
> AN> requirements. This type of system isn't timed at all-- fuel is
spraying into
> AN> the intake port even when it's closed. As a result, some fuel
condenses out
> AN> onto the intake runner walls during this period.
>
> AN> A timed mechanical injection system such as the Lucas or Tecalmit-
Jackson,
> AN> is similar but it sprays fuel intermittently from each injection
nozzle,
> AN> timed for when it is the optimum point for that cylinder to receive
it. This
> AN> improves the efficiency of the mechanical system.
>
> AN> Both types of mechanical FI systems work well for full- load operation
but
> AN> they don't compensate for light engine loads, temperature, barometric
> AN> pressure, etc., etc. EFI, on the other hand, provides an automatic
> AN> adjustment for a whole host of engine parameters and essentially
"optimizes"
> AN> the fuel delivery based in the engine requirement at that particular
> AN> instant.
>
> AN> Everybody has their own variation of these basic systems but their
> AN> fundamental principles are similar.
>
> AN> Regards, Neil
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