Research work on automobile and other internal combustion engines has been carried on in the department since 1913. Early work was restricted for the most part to the automobile, although a project on the engine, consisting of a heat balance study, was initiated in 1915. The results are still quoted as the most complete available on that type of engine. Work was also begun on a study of car resistance, and the various aspects of this problem have been studied more or less continuously since.
The laboratory was one of the first to present comprehensive data based on actual experiments showing the advantages of streamlining. The wind tunnel model built about 1930 had some of the best features of the present streamlined cars. An outgrowth of this resistance work was a co-operative study made with the State Highway Department to determine which of the grades in new construction were more economical, considered from the standpoint of Page 1271balancing the cost of construction against the operation cost of cars and trucks in climbing the grades.
The laboratory has co-operated with manufacturers and has studied almost all car and engine parts either with a view to improving them or to checking the improvements being attempted by the manufacturer. The engines worked on have varied from small single-cylinder ones for marine work, household equipment, and farm-lighting to twelve-cylinder airplane engines. Pistons, rings, pins, connecting rods, and crank shafts have been improved. Valve mechanisms, carburetors, manifold systems, and combustion chambers have been studied. Experimental work has been done on ignition and injection systems for both diesel and Otto cycle engines, bearings, lubricants, and fuels and their effect on engine parts and engine operation.
Extensive work has been completed on chassis parts, hydraulic transmissions, universal joints, propeller shafts, rear axles, brakes and brake linings, wheel types, springs, shackle bearings, front axles, and steering gears. Studies have been made of car performance, riding comfort, including the development of the Universal Test Seat and Universal Driver's Compartment, car safety, and car noise, particularly mufflers.