Half Scale Oil Pull Rumely Tractor

Half scale oil pull rumely tractor AG WORLD Ag World 15-2-19 Mike Kolb, Sr., Oshkosh, Wis., built a half-scale "Oil Pull" tractor modeled after an old 1920 Rumely tractor that ran on kerosene. The steel-wheeled tractor, made mostly from scrap iron, runs, rides, and drives almost like the real thing and is used to power a miniature Case threshing machine that Kolb also built. The tractor, 6 ft. long and 5 ft. high to the top of the steel roof, is powered by a 10 drawbar hp (20 belt) home-built 2-cylinder gas engine. It has a 3-speed Chevrolet car transmission that's chain-driven off the engine. "I've always been interested in the Rumely Oil Pull tractor. Rather than trying to obtain and restore one, I decided to build a half scale model," says Kolb. "Kids love to drive the tractor in parades. Top speed is 2 1/2 mph which is a little slower than the real Rumely tractors. It runs beautifully and looks and sounds like a real Rumely. Exhaust comes out an 8-in. opening on top of the radiator. It took me 1 1/2 years to build it." Kolb modeled his tractor after a full-size 1920 Model 20-40 on a farm about 10 miles from his home. He made several trips to the farm, measuring and sketching every part of the tractor he could get at and taking numerous pictures. At an old time engine show he found a Rumely manual showing the break-down of the engine, transmission, drive gears and running gears. He used channel iron to build the framework and axles and had the metal for the wheel rims rolled at a sheet metal shop. He then made the hubs and spokes from scratch and welded them to the wheels which are 20 in. tall in front and 3 ft. high at the rear. He used sheet metal to form the radiator housing and electrical conduit to make cooling tubes. A pair of exhaust pipes lead from the top of the engine heads to the radiator. He made the flywheel by duplicating the flywheel on an old gas engine that he owned. He bolted a reduction gearbox onto the transmission to reduce speed. The transmission gear drives the rear axle which in turn drives a pair of larger gears bolted onto the rear wheels. The last and most difficult part of the project was the engine. Kolb built the block, crankshaft, cam shaft and heads. He found that the connecting rods, piston and sleeve assembly, cam drive gear and governor from a 1936 Case tractor were half the size of the Rumely so he used them in the engine. He used a 4-cylinder Jeep down draft carburetor and built his own oil pump. He starts the engine by rotating the flywheel by hand. Kolb built his 1939 Case threshing machine on a 5 in. to 1 ft. scale. It has 1-ft. high steel wheels and is equipped with a 13-in. cylinder and a 23-in. wide straw rack. The 5-ft. long blower pipe can be telescoped out another 1 1/2 ft. Contact: FARM SHOW Follow up, Mike Kolb, 1362 Valley Road, Oshkosh, Wis. 54904 (ph 414 235-4314).

To read the rest of this story, download this issue below or click here to register with your account number.