Dual fuel PFI rails....

[Frederic Breitwieser]

Howdy Barry,

> Looks like you advise me on another project!  The video work went by the board for two months while I tracked down a 'lousy running' problem that turned out to be a plugged cat converter.  
Ouch,that sucks!  I killed yet another junkyard 318 in my truck,
though I did paint it recently, and it came out acceptable for a
backyard paintjob.  http://www.xephic.dynip.com/dodge/dodge.html

>How's your quad LCD project going?

Its not... I pushed it aside for later efforts... too much "garage"
stuff to do while its hot out.  I have the following projects going:

1. weld mid-engine chassis together.
2. install 383-->431 twinturbo stroker into truck.
3. install EEC-IV or GM730 ecm into truck upon 383 stroker.
4. install new suspension on my Lincoln (higher priority)
5. install dually rear onto truck.
6. fabricate dually fenders for truck (and install).
7. rewire truck.
8. continue experiments with 12V in PC switching power supply.

I have a 70 continental to sand, derust, and paint, as well as a early
60's suicide door continental to sand, derust, weld, paint, and repair
pretty much everything :)

Feel free to come visit and pitch in :)  The 4-LCD display thing is
kinda on the back burner.  Been trying to find an ISA card that does
the same thing, making it much simpler than building a video card from
scratch.  Slowly, as time permits.

> Anyhow, what I envision isn't 2 injectors per cylinder, but two rails feeding a single injector (already in place) w/ two different fuels.  Would have to fab a complete manifold for my Sy to mount two injectors per cylinder, *definitely* something I don't want to get into!

Well, the only concern I have with two fuel rails and one injector, is
what happens if the line pressure on one fuel deteriorates?  Then the
second fuel will push back through the other fuel rail and end up in
the tank, reducing overall fuel pressure, and mixing the fuels. 
Having two injectors per cylinder, irregardless of the fuel choices,
ensures a failsafe mechanism whereas you can limp home using the other
set of fuel rail/inejctors if you have some neat programming in the
ECM :)

> Machining the six needed Al blocks wouldn't be hard, but all the fittings might be.  Each block (holding one injector) would have two fuel inlets & 2 outlets.  That's four connections per block, a total of 24 connections to make for a V6.  Probably isn't physical space for such a thing, and a leak *somewhere* seems inevitable; plumber's nightmare!

On the Buick V6, we had three injectors per cylinder, two for gas and
one for an 80/20 mix of isopropol and distilled water, all running in
parallel.  We had 10-12" of space on the runners on the intake, so
there was room for all of this "stuff".

>injector for one cylinder.  Common volume would be too large to allow rapid switching of fuels w/ this arrangement, but that's the idea.

Two rails, one gas, one alcohol, with a "T" between, feeding on
injector.  Got it.  This allows cross-flow of the fuels if the
pressure drops, and you'll mix.  two injectors I think are a better
solution, but I haven't experimented with your idea, so I can't say
for sure.  You'd need some kind of check valve either at the "T"
joints or maybe back at the start of the fuel rail where the fuel
lines feed into, thus preventing mix and contamination.

Also realize by mixing before the injector, you have much less control
of the ratio between regular fuel versus special fuel.

Just some random thoughts.

>need a *long* 5/16" drill.  Guess the question *really* is, can *I* do it; probably very do-able by a pro!

I made my own fuel rails.  if I can do it, anyone can :)


-- 

Frederic Breitwieser
Bridgeport CT 06606

1993 Supercharged Lincoln Continental
1989 HWMMV w/turbocharged 500cid Caddy
1975 Dodge D200 Club Cab soon to have 431 stroker + turbos
2000 (I hope) Buick GTP (Mid-Engined Sports Car)