CNG/LNG

[Darrell Norquay]

>         I remember reading an article on natural gas injection that was put
> in a 302cid Ford Mustang which, incidentally, utilized the FACTORY ECU. I

>         I also recall that the stated octane rating of the gas is
> 130....could anybody verify this, and if so, why not run a 10:1 compression,
> bump the timing up a little, and run 10 psi of boost???(can't do that with

Compressed Natural Gas (CNG) does have an octane rating somewhere near to
130 - you can run 25 degrees initial advance, and upwards of 35 total.
It's cheap, (at least here in Canada), and it has VERY low emissions.
Having said that, it is stored in tanks at up to 3000 PSI, which means
they are big, heavy, and they don't hold much fuel.  Typically, range is 
very limited.  It's hard to find fuelling stations, (getting a bit easier)
and it takes half an hour to fill up.  Plumbing and installation is very 
expensive, all stainless hard tubing (no hoses allowed).  Doesn't have as
high a specific energy rating (per lb) as gasoline, making fuel consumption
much higher.   All in all rather impractical for a street vehicle.  There's
no reason you can't run turbos and high compression with CNG, it's just
that nobody does... (Taxis, couriers, etc use it somewhat, and our local gas 
company's service vehicles are all CNG - it figures)  

Propane (LPG), however, has a pretty good octane rating(110-115), is also 
cheap, clean, and the tanks and plumbing are much lighter and less costly 
since you only have to deal with a couple of hundred PSI.  Tanks also hold 
more fuel since it is in a liquid state instead of a gas, and you can get 
it anywhere.  Ideal fuel for use with turbos and superchargers.  All in all 
IT IS a good fuel for a street/high performance vehicle.

Both fuels promote long engine life because of the cleaner combustion and
the fact that these fuels are not solvents like gasoline and don't wash the 
lubricating oils off cylinder walls and valve guides, etc, thus prolonging
their life substantially.  Half a million miles is not too unusual between
rebuilds on a propane engine, if it was built specifically for propane in 
the first place...

There are no stupid questions, only stupid answers...

regards
dn


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 Darrell A. Norquay              Internet: dn at dlogtech.cuc.ab.ca     
 Datalog Technology Inc.         Voice: (403) 243-2220
 Calgary, Alberta, Canada        Fax:   (403) 243-2872            
 
       "Absolutum Obsoletum" - If it works, it's obsolete    
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