McIntosh & Seymour Diesel engine, of the A frame design, is practically identical with the product of the Aktiebolaget Diesels Motorer (Swedish Diesel Engine Co.) of Sweden. As outlined in Fig. 9, the engine frame or base is a low box section casting some 12 inches in height. This frame rests directly on the foundation. To the base are bolted the A-frame castings, which are of cylindrical form at the top to receive the cylinder liner, in this way acting as the cooling jacket outer walls. In the 500 h.p. unit there are four cylinders and A-frames, while the air compressor is mounted in line with the power cylinders on a similar A-frarine but of much lower height.
The camshaft is carried at a level with the cylinder heads and is driven by a vertical shaft and bevel gears; the shaft carries the governor while the fuel pump is supported on one of the cylinder castings. • The McIntosh & Seymour Corporation has now virtually abandoned the A-frame engine for stationary work and are centering their manufacturing facilities on the box-frame engine. Beyond the frame itself, the engine has been modified in no way, the details of valves, governors, etc., remaining as before. Figure 10 is a view of the box-frame engine. These engines range in size up to 1000 B.h.p., which unit is of six-cylinder construction.
Worthington Pump and Machinery Co. Diesel Engine.— This corporation manufactures, at the Snow Works, a Diesel type engine under the name of "The Snow Oil Engine." This engine, which is of horizontal construction, is manufactured in units from 65 h.p. to 800 h.p. It does not follow standard Americ'an Diesel engine practice in that a cross head is used in preference to a trunk piston. This necessitates the lengthening of the frame.
The main frame, Fig. 11, is of box section with both longitu dinal and transverse ribbing. The single and twin cylinder units have a one-piece frame, while the frame of the three-cylinder engine is of two-part construction to facilitate shipping and erec tion. As seen by Fig. 11, the frame is extended to form the cylinder cooling jacket; the liner is separate and is forced into the jacket cavity. The air charge for the engine cylinder enters the frame at one side of the crankcase and flows along the frame before passing through the admission valve. The air com pressor is mounted on the engine frame and is driven by a crank keyed to the engine shaft. The valves are controlled by a cam
shaft placed transversely in front of the cylinder head; this shaft is driven through bevel gears by a layshaft at one side of the engine. This latter shaft also drives the governor and fuel pumps.
Allis-Chalmers Diesel Engine.—The frame is of the box type, Fig. 12, and is so designed as to allow the engine shaft to rest deep in the bearings. This gives the engine a low center of gravity, making it rigid and fairly free from vibration while in operation.
As with all modern Diesels the frame forms the cylinder jacket, while the liner is held in place by a flange at the head end. The valve mechanism is driven off the longitudinal layshaft, which also handles the governor and fuel pump. The Allis Chalmers engines are manufactured in single, twin, triple and quadruple cylinder units. The single and twin engines are both built with a one-piece frame. The triple-cylinder unit consists of a single and a twin engine with the flywheel between the two en gines, the two-piece shaft being flanged and bolted to the wheel hub. The quadruple-cylinder engine is obtained by using two twins with the flywheel between the two frames.
National Transit Pump and Machine Co. Diesel Engine.— The engine manufactured by this company is of horizontal design, as outlined in Fig. 13, which brings out the massive lines, particularly those of the bearing housing footings. The engine is built in one and two cylinder units. As usual with the horizontal design, a layshaft is employed to control the valve mechanism, as well as to drive the pump and governor.
McEwen Bros: Diesel company is one of the later firms to embark upon Diesel engine manufacture. The engine closely resembles other American units, being of the hori zontal design, Fig. 14; the cylinder liner is pressed into the jacket, which is a part of the frame. The piston is of the standard trunk design. The valves are vertical, and both admission and exhaust valves are provided with cages. The valves are controlled by separate eccentrics while the injection valve is actuated by a cam. The air compressor, which is two-stage, is driven by a crank extension of the engine shaft. No air storage is employed, a small bottle being placed in the air discharge line to absorb the air pulsations.