Evan Perkins
June 20, 2016

We see it all on HOT ROD Power Tour. New, old, and every make and model you can wrap your car-loving brain around. So it was no surprise when Jason Amos rolled in with wife, Becky, in their 1970 Ford XL. What was a surprise was learning the couple had covered over 1,000-miles of the trip on propane.

Jason bought the car on Craigslist in 2012 from the head of the automotive shop department at Burbank high school. “I’d been looking for an XL,” he said. ”I like big-blocks and I like odd balls.” At the time of purchase, west-coast gasoline prices near Jason’s Los Angeles, California home had spiked to over $4.00 a gallon and propane was just $1.50. The car made sense, and satisfied his inner car guy.

While it works well, the propane conversion on the car is a bit of an enigma. According to Jason, it was supposedly installed sometime in the ‘80s in Mexico, but little else is known about its origin. The purpose of bringing the car on Power Tour was to raise awareness of alternative fuels. “I wanted to open up a little bit of a dialogue about alternative fuels and Hot Rodding,” said Jason.

Jeff Hall, Business Development Manager at IMPCO Automotive, is tagging along with the Amos’s to promote propane vehicle conversions.

We asked him about the system installed on the car, to which he laughingly replied it predates him by about 30 years. Impco, which has been around since 1958, manufactures equipment to allow internal combustion engines to run on propane. The company focuses primarily on large-scale fleet vehicles and trucks, but does have a few car offerings. However, they never made a conversion for a Ford XL and certainly not in 1970.

The car is capable of running on gasoline or propane, and a simple switch under the dash allows Jason to flip between the two. He’s run about 85-90 percent of the Power Tour on propane, but had to fill up with gas in rural Louisiana when he couldn’t find propane.

So while the conversion’s actual whereabouts may be a mystery, after spending a few minutes under the hood, its basic function seems pretty self-explanatory. We spotted a solenoid inline with the carburetor fuel inlet that we assume opens and closes via the under-dash switch to shut off fuel flow while the car is operating on propane. “If I’m running gasoline and want to switch over to propane, I have to blow the gas out of the carburetor or it runs like it has two dead cylinders for about 5-minutes,” said Jason. We imagine that when the propane comes on, leftover fuel in the float bowl causes the car to run pig rich, in conjunction with the propane, and stumble until it burns off. “When you switch from Propane to gas, you don’t have to do anything”, added Jason. “You could do it at 55 MPH.”

The tank that holds the propane is mounted in the trunk of the car and, according to Jason, holds enough fuel for about 250 miles of driving. It’s also good to the last drop, as Jason has run it on fumes for over an hour. From the tank, propane flows to the engine bay where it hits what appears to be an atomizer. There is a T-fitting on the heater hoses that routes hot coolant to the atomizer, likely to provide a heat source and keep it from freezing over. As propane phase shifts from a liquid to a gas, it expands and rapidly cools, hence the need for heat.

From the atomizer, propane flows into a mixing device after the air cleaner. There is a cable linkage coming off the mixer that we assume is referenced off of throttle position to either increase or decrease propane flow through the carburetor, which in propane mode has no gasoline flowing to it. Despite its “from-places-unknown” condition, the old Impco system works, and well.

Jason is an independent filmmaker from the Los Angeles Area who actually acquired the car for a movie he is making, called Marathon. Originally, the car was set to be crushed for a scene in the film. However, after driving the car, Jason fell in love with it and it will now assume more of a “hero” role.

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