Join Date: Mar 2007
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The conversion is gas to propane or dual fuel - gas and propane with a switch.
Mount a DOT propane tank with the high pressure fuel gas fuel line to the sut off solinoid and on to the regulator, from the regulator a large low pressure hose to the carb or adapter.
Propane is high octane ( I think 120 ) and picky about the ratio. It will not fire with the mixture off by very much. The compression ratio can be upped a lot for a propane only engine, as can the spark advance.
There is about a 10% loss in fuel mileage on propane with a dual fuel but the changes in a propane only engine can give 10% better with propane - it just won't be easy to go back to gas for fuel.
My uncle bought propane for $30 a thousand gallons at the refinery in the early 50's so there was a real saving in cost of fuel. The down side was that it cost about 4 engine overhauls to do it right, At that time you could get an overhaul starting at $150 and for propane $340 and the kit was $400. Today kits start around $1200 and many engines will run as is but the propane starts at $2.50 a gallon and here they add a tax sticker for $128 a year last I heard so most went back to gas. Not a lot of difference between an electronic fuel injection with unleaded and propane.
For diesel, propane supplementation contributes a catalytic action at low ratios and can be used at stronger ration as just more fuel with a lower EGT, much the way that methanol/water works. Spray it in with boost and get lower EGT with higher HP numbers. They work as long as the ratio remains below the mixture needed to fire by compression.
93 Dodge /CTD, IC, 518, club cab LE, BHAF, KDP fixed, kelderman air ride
81 Isuzu /C223na, 5spd