THE properly designed two-cycle Diesel is the answer to the problem of building an automotive-type Diesel engine that compares favorably with conventional gasoline engines as to size, weight, and power, Mr. Shoemaker asserts. His paper is chiefly concerned, he announces, with the problem of producing such an engine that will use the same materials, design practices, manufacturing methods, and mechanical parts as are common practice in production-type gasoline engines.
Scavenging is effected in these engines, Mr. Shoemaker explains, by using piston-controlled inlet ports and poppet exhaust valves in the head.
The author shows how a change in design of the blower to a three-lobe helical-rotor type reduced noise and improved discharge characteristics. Piston cooling is effected by coring out the rim of the piston between the piston crown and the ring belt and cooling the crown directly by oil spray, he explains, adding that this cooling reduces the ring-belt temperature well below the coking or gumming point of ordinary oils.
In the remainder of the paper he discusses injection, engine-balance problems and the commercial problems involved in designing the engines and parts to meet a wide variety of applications.