Dick;
A continuous- flow FI system such as the Hilborn, Crower, Kinsler, Algon,
etc., simply sprays fuel continuously from each injection nozzle. The amount
of fuel delivered depends on the injector orifice size and fuel pressure.
The fuel pressure is controlled by a barrel valve that is opened & closed by
the throttle position. There are also other controls such as fuel return
jets, etc. that allow the fuel delivery curve to be tailored to the engine's
requirements. This type of system isn't timed at all-- fuel is spraying into
the intake port even when it's closed. As a result, some fuel condenses out
onto the intake runner walls during this period.
A timed mechanical injection system such as the Lucas or Tecalmit- Jackson,
is similar but it sprays fuel intermittently from each injection nozzle,
timed for when it is the optimum point for that cylinder to receive it. This
improves the efficiency of the mechanical system.
Both types of mechanical FI systems work well for full- load operation but
they don't compensate for light engine loads, temperature, barometric
pressure, etc., etc. EFI, on the other hand, provides an automatic
adjustment for a whole host of engine parameters and essentially "optimizes"
the fuel delivery based in the engine requirement at that particular
instant.
Everybody has their own variation of these basic systems but their
fundamental principles are similar.
Regards, Neil
-----Original Message-----
From: Dick J [mailto:lsr_man@yahoo.com]
Sent: Monday, April 29, 2002 9:56 AM
To: Albaugh, Neil; 'Keith Turk'; ardunbill@webtv.net; Dave Seely;
land-speed@autox.team.net
Subject: Fuel Injection
"Albaugh, Neil" <albaugh_neil@ti.com> wrote: . . . . . . .was probably
one of the most advanced mechanical FI systems ever built and it provided
better performance in road racing
applications than continuous- flow systems
Okay, how about a "fuel injection primer" for a stone age mechanic. I
thought all injection was timed. Kind of like a distributor or something
that made each injector spurt only when it was the right time. Would
somebody be willing to give some really, really basic definitions and
descriptions of these different injection systems. Mechanical (timed and
untimed?), electronic (is that timed?), throttle body (timed all the time,
increased flow at throttle opens??). I'm confused. How does the density of
the fuel charge get increased and decreased as the air flow is increased and
decreased with the butterfly?
Dick J
/// unsubscribe/change address requests to majordomo@autox.team.net or try
/// http://www.team.net/mailman/listinfo
/// Archives at http://www.team.net/archive/land-speed
|