Half-breed tractor?

By Staff
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Photo #1: Jim Hunter driving his tractor at the 2004 Portland, Ind., show.
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Photo #2: Jim standing with his creation.

I am always amazed at the creativity of people in the old engine hobby. One such person is Jim ‘Jack’ Hunter, of Kerry, Ohio, who has managed to bring together two hobbies – tractors and oil field engines – in a most interesting way. Jack mounted an A.C. Thomas half-breed oil field engine on an Allis-Chalmers WC tractor.

The WC tractor was drafted into service 20 years ago, when the frame was extended 40 inches in order to house the A.C. Thomas engine Jim had acquired.

The restoration of the engine and adaptation of the tractor to accept its new power source started in earnest two or three years ago. The engine was seized, the crosshead needed to be realigned and it needed new bearings. A new hot tube system was constructed and a provision was made for spark plug ignition. The engine has an especially old bedplate, as evidenced by the ornate style of lettering, which reads ‘Oil City Boiler Works, Oil City, Pa.’ The A.C. Thomas conversion cylinder, rated at approximately 10 HP, was built in Bradford, Pa., and distributed by Bradford Supply Co.

Power from the engine to propel the tractor is fed back through the tractor’s belt pulley. When starting the engine, power is sent in the opposite direction to turn the engine over by means of a 5 HP Briggs & Stratton engine and hydraulic pump and motor. This assembly is attached by chain to the transmission, where the tractor’s original engine would’ve been. The hydraulic system works rather well in cranking the engine for starting, and is also used to propel the tractor when the oil field engine is not in use, such as when loading onto a trailer. While under power of the oil field engine, the tractor moves at a walking pace, with some expected imbalance, but nothing overly aggressive.

Jim says his father has always been amazed that the 5 HP Briggs & Stratton engine and hydraulic unit can crank the big oil field engine over, but the whole system works really well and is definitely an attention getter and crowd pleaser – a real ‘Oaf’ or ‘OFES’ tractor.

Contact the Oil Field Engine Society at: 1231 Banta’s Creek Road, Eaton, OH 45320-9701;oilengine@voyager.net, www.oilfieldengine.com

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