Written By Larry Gay
The Oliver Farm Equipment Company was formed in 1929 by merging four farm equipment companies including the Oliver Chilled Plow Works and the Hart-Parr Company, a tractor manufacturer. When three new Oliver Hart-Parr tractors were introduced in 1930, the Oliver name was in little letters and the Hart-Parr name was in big letters on the top tank of the radiator. In the fall of 1935, Oliver introduced its second model of row-crop tractor, the Oliver Hart-Parr 70. This time the Oliver name on the front of the tractor was in big letters and the Hart-Parr name was in little letters.
Oscar Eggen, Oliver’s Chief Tractor Engineer, was a student of the automobile industry and he observed cars had an enclosed engine compartment, were covering the radiator with a grill, and were offering more models with 6-cylinder engines. Therefore, he applied these same ideas to the new Oliver Hart-Parr 70 tractor. It was built with a grill over the radiator, engine side panels to enclose the engine compartment, and a 6-cylinder engine. This styled appearance combined with a 6-cylinder engine is what made the Oliver Hart-Parr 70 tractor unique.
The Oliver Hart-Parr 70 was rated as a 2-plow tractor and was powered by a 6-cylinder, 201-cubic-inch Continental engine built to Oliver’s specifications. There was a high compression (HC) version of the engine which burned 70-octane gasoline and a low compression (KD) version which burned kerosene or distillate. The two versions of the engine used different cylinder heads and manifolds. The requirement for 70-octane gasoline for the HC engine was the source of the tractor’s 70 model number.
The 4-speed transmission provided speeds of 2.4, 3.3, 4.3, and 5.9 mph at the rated engine speed of 1,500 rpm. Large diameter Tip-Toe steel wheels or 8.25-40 rubber tires provided clearance for row crops and were attached to splined bar axles to provide an adjustable wheel tread. Two cross pipes passed through the tractor’s frame to carry the mid-mounted implements. A power lift, PTO, and belt pulley were optional as were lights and an electric starter. A unique rod frame and hammock type of seat was provided for the operator. The clutch pedal was now located on the left side and foot pedals for the brakes were located on each side of the transmission.
In the summer of 1936, Oliver introduced two additional versions of the Oliver Hart-Parr 70. One was a standard-tread version identified as the Standard 70 and an orchard version with fenders over the top half of the rear wheels known as the Orchard 70.
Larry Gay is the author of four tractor books published by the American Society of Agricultural and Biological Engineers, including A Guide to Hart-Parr, Oliver and White Farm Tractors. This book may be obtained from ASABE by calling 800-695-2723.
