Propane Motor Fuel Injection

[Jonathan R. Lusky]

dn writes:
> I'd definitely like to know more about this.  I in fact, do have an OHG
> X450, but I got disgusted with it after dinking around with various 
> combinations of the available fuel metering rods.  At the time, I couldn't
> see spending loads of time and money trimming a thou at a time off the metering
> rods, but if you can share some of the tech secrets with me (such as where 
> and how much to shave off), I'd be willing to resurrect the thing...
 
We were shooting for stoich across the board (running CNG).  I'm not
sure what mixture you need for propane.  What we did was play width
different valves and heights (you can adjust the height with a punch and
a hammer) until we had something the was great from idle through about
70HP.  That configuration left us with something that leaned out steadily
from there up.  Then we machined a taper on the outside of the valves.
Kept remachining with a steeper angle until we got it right.  I don't
know what angles we started at and ended up with.  It did take a good
amount of time...  but i've never been able to get fuel mixture that
close across that wide a range with a gasoline carb.  I was using
a Horiba AFR meter (EGO based) to monitor air/fuel ratio.  One
note--we didn't have all three valves at the same height.  I'm not sure
why, but when running all three valves at slightly different heights we
got some interesting transient behavior--deceleration enleanment.

> > I believe BKM makes injectors (designed for CNG) that will handle 150psi
> > EFI kits for propane.  You might see if Stewart-Stevenson has one...
>  
> Do you have addresses and numbers for these guys?
 
Nope, sorry.  Should be in Thomas Register...

-- 
Jonathan R. Lusky                        lusky at knuth.mtsu.edu
http://www.edge.net/~lusky/                 (615) 726-8700
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68 Camaro Convertible - 350 / TH350  \_/ 80 Toyota Celica - 20R / 5spd