Detroit Diesel 110 - Overview

Overview

The Detroit Diesel Series 110 is a two-stroke cycle Diesel engine series, available in six cylinder inline configuration (in keeping with the standard Detroit Diesel practice at the time, engines were referred to using a concatenation of the number of cylinders and the displacement, so this was a model 6-110). It was introduced as the second mass-market product of the Detroit Diesel Engine Division of General Motors in 1945.

The 6-110 series engines utilize uniflow scavenging, where a blower mounted to the exterior of the engine provides intake air through cored passages in the engine block and ports in the cylinder walls at slightly greater than atmospheric pressure. The engine exhausts through push-rod operated poppet valves in the cylinder head, with either two or four valves per cylinder. Unit fuel injection is employed, one injector per cylinder, with no high fuel pressure outside of the injector body. The injectors are cycled from the same camshaft responsible for opening the exhaust valves.

As a two stroke cycle Diesel engine cannot naturally aspirate, or draw in its own intake air, the blower is necessary to provide air in an amount sufficient both for scavenging of exhaust gasses from the cylinder and to support combustion. Initial versions of the 6-110 engine used a centrifugal-type supercharger. This was very practical for fixed-speed applications such as marine or generator service, but proved a failure in automotive applications. "The engine was developed on the dyno and was never operated above rated RPM. The first application was in Euclid mining trucks, where the driver's income depends on how fast he drives the empty truck back down into the pit. The centrifugal blower ran about 10 times engine speed. Exceeding that RPM was fatal, and in a truck a single missed downshift could mean a failed engine." For that reason a Roots type blower was made available as an option after about 1952. Later high performance versions were available with turbochargers.

The initial Series 71 engines from Detroit Diesel were produced in 1-, 2-, 3-, 4- and 6- cylinder versions. The most powerful version, the 6-71, displaced 426 cubic inches and produced 170 hp (127 kW) at 1800 rpm. While these engines with their low cost and relatively light were highly successful, there was also great demand for higher horsepower, especially for non-highway applications such as power generation and construction equipment.

Since inline engines of more than 6 cylinders tend to have substantial technical problems, and since GM was not to perfect V-block engine technology for another decade, they took two divergent approaches to achieving higher horsepower. One was to couple together multiple 6-71 engines in twin (side-by-side), tandem (fore-and-aft) and the incredible Quad (four 6-71s all driving a single shaft). While these did produce high horsepower and even added some redundancy, they were mechanically complex and relatively expensive.

The alternative approach was to design a new engine and increase the displacement from the existing 71 cubic inches to 110 cubic inches, or roughly a 50% increase. This resulted in the model 6-110 or 660 cubic inches total displacement. While the basic engine components (block, crankshaft, pistons, etc.) were all new, many of the additional components (injectors, governors, accessories, marine gears) were simply shared with the Series 71 engines. Since the 6-110 was designed from the outset for heavy-duty high-horsepower applications, it was never produced in a four cylinder version (that would have displaced 440 cubic inches, very close to the 426 ci displaced by the 6-71).

The introduction of the V-71 series in 1957 effectively doomed the 6-110, as both the 8-71 (568 cubic inch displacement) and 12-71 (852 cubic inch displacement) offered higher horsepower in a more compact form factor. However the high torque and great reliability of the 6-110 was still valued for heavy-duty applications.

The Series 110 was last produced in 1965, after which the manufacturing rights were purchased by the W. W. Williams Distribution Company, which continues to provide parts for these engines.