Fuel injection plugs

[Howard Wilkinson]

Greg:
    I've personally seen irrigation pump motors run on propane over
10K hrs.  This is a considerably different environment than a farm
truck.
    As for Holley carbs, it is unfortunate that pot metal has very low
salvage value.  I'll just have to take your word for it on the
potential of these carbs.... I've never seen it.   When you do get one
of these working halfway decently, they have a very short life
expectancy between overhauls.  I've over the years replaced every
Holly carb I ever owned with the good old style Autolight / Motorcraft
carbs that actually can be made to work correctly and efficiently
throughout their operating range.  It is unfortunate that the Holly,
Motorcraft, and Autolight carb familys used neoprene diaphragms in
accelerator pumps and in power valves.... they don't like today's gas
at all.
    Personally I feel that of the 4 bbl carbs available, the plain old
Quadrajet would have had the most potential of any of them if they had
only made replaceable secondary orfices.... once these are worn
there's nothing to be done.  I've built a puller and removed them, and
I suppose you could manufacture a replacement, but......   Now we've
got EFI.
    I take nearly all horsepower claims with more than a grain of
salt...... I also must confess to be a grave doubter of bscf numbers.
What I've often run into in the aviation field are people who state
the max horsepower, and then state a fuel consumption figure which is
obviously taken at 20% or 30% throttle in such a way as to imply that
their engine for example puts out 100 hp on 2 gpm when in truth their
100hp engine will not put out a sustained 100hp, nor will it do it on
the absurd figure of 2gpm.  The engine is in fact putting out about 24
hp when the fuel consumption is measured.  I suspect that this
nonsense is not confined only to aviation.  All bscf figures which
exceed .5 by very much automatically fall under suspicion here
:-)..... No offense intended.          H.W.


-----Original Message-----
From: Greg Hermann

>The 500K figure takes a good engine to begin with, and then some high
tech
>tricks and quality parts on top of that. The engine I have started
out with
>has a lengthy track record of running 10K hours on the heads, and 25
K
>hours on the bottom end, on natural gas, at about 80% load, 2400 rpm
on
>well head irrigation pump applications.  And that--with "farmer"
>maintenance! So--I think, with some careful attention to details, my
>durability goal is attainable.
>
>As to the bsfc--check out some dyno charts for small block f & c
engines
>running IR manifolded Weber carbs. .375 bsfc is common on these
engines
>with this type of an induction setup and good headers--given a
competent
>tuner. In fact--these numbers could just lead a guy to believe that
there
>is something to this business of wanting better fuel atomization and
a fuel
>squirt timed to coincide with high inhale velocity in the port!
So--with
>good efi, .35 should be within reach for light loads. The real
challenge
>will be in seeing how much lower than that can be had!! A competently
tuned
>Holley will get down to about .45 bsfc on a decent motor, in my
experience.
>(Somewhat lower if not into the power valve, and maybe just a little
higher
>at WOT if you know how to set the pvcr correctly.)
>
>Regards, Greg
>
>
>