Alternate fuel EFI

[Markus Lien]

>What the heck kind of a mixer is this?  Thought I'd seen em all...

Vialle mixer, my description of it is a little slanted as I am offended
that I actually puchaced such a poor system.

>All propane mixers suck!  I haven't found one yet that does a decent job
>of it.  Tried Impco, OHG, and now I'm running a Century mixer, on my 350 

I first came in contact with this TechnoCarb company because the manufactuer
a fantastic mixer.  Their design uses the throttle plate from a Quadrajet
carb and places it under a set of 4 large diameter anterior vented (not
positive about the terminology) verturi.  this system is incredibly 
accurate but I would be suprised if it even flows 450 CFM :-( on my 383
power flattens out at about 2500 RPM.  Part number I used 4SS350

>
>> I eventually came across (I'll call it an Electronic fuel control
>> system) from a company called Technocarb.  This system uses an O2
>
>I'd be interested in some more details on this system, costs, who sells
>it, etc.
>
John Carter is the founder and head engineer at Technocarb (604) 854-6264
I believe they have an 800 number now but I can't find it.  John is very 
easy to talk to and eager to chat about projects and ideas (wonder if 
he has an E-mail account ;-)).  They refer to their system as a "feed
back" system refering to the fact it uses an O2 sensor to monitor AFR.
Part number I used is EFS-400P.  They build a TPS emulator for 75 bucks
but it just uses RPM, therefore resulting in bad throttle response.  I
just mounted a TPS on my throttle plate and built a regulated 5 volt
power supply to feed it.  Throttle response is incredible!
>
>Damn, 18 MPG is just a dream with me,  my engine gives about 12 around
>the city...
>
I cheat! Low rear-end gearing boosts arount town mileage, adding an 
overdrive trans doubled my highway from 9 to 18.

> BTW, you can buy rebuild kits for the vaporizer for around 30 
>bucks, beats hell out of buying a new one.  Piece of cake to install, too.
>
You guys with your Empco vaporizers! I'm green with envy, Vialle dosn't want
anyone to open their evaporators.

>The current idea I'm working on is to use the fuel in the gaseous state,
>using half a standard vaporizer, (remove the fuel pressure regulator guts)
>and regulating it with a standard gas regulator to somewhere around 50-60 
>PSI (maybe higher).  Feed this into a standard dual TBI type injector, and 
>see what happens.  The higher-than-normal fuel pressure should allow the
>injector to supply enough fuel (even though it's designed for liquid fuel) 
>but not so high as to affect the opening time.
>
I see my description of my Technocarb system was weak.  what you have
described here is very much a Vialle evaporator coupled with the 
Technocarb feedback control system!  the electronically controlled power
screw functions the way the TBI would with your plan.  Rather than holding
back a positive presure from the vaporizer it just restricts vacuum from
the mixer.  Maybe you have comeup with the improvement I need in my system!
the Vialle evap could very easily be modified to supply a positive presure
to the power screw.  A couple of PSI would be sufficient as the power
screw can open to a .75" orifice.  I could then replace the mixer with 
something which simply mixes the air and vapor rather than generating a 
vacuum signal

>> The engine is a 350 stroked to 383 using Kieth Black silv-o-lite
>
>Yeah, when my 350 bites it I'd like to go with a 383 conversion...
>
The 383 is a torque factory! real fat till the tiny mixer chokes the thing
out!  Not cheap though, my engine builder went all out, Stainless valves, 
Competition Cams propane performance cam, shaved heads and used the long
connecting rods with the low deck KB pistons.  $3400 and I wrote a piece 
software for capturing data from his dyno and located 3 extra 400
crankshafts.  Add to this the money I've poured into fuel systems and I 
think I should have bought a multport 350 from a wrecked Z-28 ;-) !!

>  Propane should be the fuel of choice, at least here in Canada,
>an' it's CHEEP!  I been running it for years, and bitching about the lack 

Yea! except here in Saskatchewan where the ^%$^%$*#(*&*@ retailers are
price fixing, propane has the same taxes here as Alberta but I'm paying
$0.40 / Litre! (Ranting, Raving, Stomping)



                                Markus