«Previous    Next»
Hybrid Fuel System Boosts Mileage
"It increases power and uses less fuel," says Colorado FARM SHOW reader Harry Wallace, who's come up with his own "hybrid" fuel system for his pickup that uses propane and gasoline.
"I've been exposed to propane as an engine fuel since 1958 when my father bought a Deere 620, factory-equipped to bum propane. Propane conversions for tractors and pickups have never measured up to the standards established by that 620 Deere and I've always felt some additional engineering and testing was required to achieve the full potential of propane as an engine fuel," says Wallace.
"In October 1990, I installed an add-on propane conversion kit, manufactured by Garretson Inc., of Mt. Pleasant, Iowa, on my 1978 Datsun pickup. This dual-fuel kit had a manual gasoline control valve and an electric control valve for propane. This set-up allowed "careless" switchovers when both fuels would enter the engine for short durations of time. I noticed drastic changes in performance during such switch-overs and decided to try to recreate this performance by metering a small quantity of gasoline into the engine along with the propane.
"I connected a vacuum-operated valve, equipped with a needle valve to control flow of gasoline, to the venturi vacuum of the distributor. Now the engine idles on 100 percent propane and burns propane with a trickle of gasoline when I accelerate and vacuum opens up the gasoline control valve.
"Since making the modification, I've had a 13 percent increase in mileage over either gasoline or propane as a single fuel and a big boost in performance. I really notice the difference since I live in Wood-land Park, Colo. (8,600 ft. altitude) and work in Colorado Springs, Colo. (6,040 ft. altitude). I drive over Ute pass daily, which has 8 percent grades, and my hybrid system lets me climb the pass at 45 mph in overdrive. The actual fuel useage ratio is 1.5 gal. of gasoline to every 20 gal. of propane.
"Gasoline ignites at 520 degrees F while propane ignites at 1,000 degrees F and octane ratings are 88 and 130, respectively. The problem with most propane, conversions is that because propane is more difficult to ignite, it doesn't bum as efficiently. Using a little bit of gasoline totally ignites the propane so the two fuels complement each other.
"To my knowledge this is the first fuel system that lets two fuels burn at the same time. All other systems are dual fuel, letting you bum one or the other. I'm currently working with a patent attorney and testing laboratories and hope to bring this system to market. The two valves I used are standard equipment with most propane conversions. However, I made slight modifications to make this system work.
"Right now I'm testing the system on late model vehicles. They're more complicated because of the computer controls. I've found I can run up to a 50-50 mix of gasoline and propane in a 1989 Ford pickup without making any modifications to the engine or controls. If I go over 50 percent propane, the computer system gets screwed up."
Contact: FARM SHOW Followup, Harry E. Wallace, Box 521, Woodland Park, Colo. 80866 (ph 719 687-3761).


  Click here to download page story appeared in.



  Click here to read entire issue




To read the rest of this story, download this issue below or click here to register with your account number.
Order the Issue Containing This Story
1991 - Volume #15, Issue #5