The Maybach engines, constructed by the Canstatt Daimler Company, are six-cylinder vertical water-cooled types following usual characteristic German form of construction. The 200-h.p. model was used exclusively in the Zeppelin, Schiitte-Lanz, and Parwcval airships: and during the war the 300-h.p. type was developed for airplane use, several having been captured in Rumpler C4 and 5 type airplanes.
One of the early Maybach engines, rated 180 h.p, at 1200 r.p.m., had a 160 mm (6.3 in.) bore, 170 mm. (6.69 in.) stroke.
Maybach and a total displacement of 1251.24 cu. in. The fuel consumption was stated to be .51 lbs. per h.p-hr., and the oil consumption .025 lbs. per h.p-hr. The weight was reported to be 990 lbs., or 5.5 lbs. per rated h.p. Cylinders of the "T" head type were constructed of cast iron.
The airship power unit, which was rated 200 h.p. at 1200 r.p.m., had a 150 mm. (5.91 in.) bore, 190 mm. (7.48 in.) stroke, and a total displacement of 1228.8 cu. in. The compression ratio was 5.94 to 1.
The cylinders consisted of steel barrels screwed into malleableiron heads with integral side jackets which were packed at the lower end. Each individual cylinder was fitted with five vertical valves in the cylinder head, two inlets of 48 mm. (1.89 in.) diameter and 9.3 mm. (.366 in.) lift, and three exhaust valves of 35 mm. (1.38 in.) diameter and 7.88 mm. (.31 in.) lift. A push rod on each side operated the inlet and exhaust valves of each cylinder by single rocker arms. A large circular water joint between each cylinder was made tight by a rubber ring encircled by a band clip of sheet brass. The crankshaft was a six-throw type supported in seven plain bearings with separate caps, and the connecting rods had square sections which were bored out. The pistons were made of cast iron and employed three top rings. The piston pin was locked in the piston and the bearing was lubricated by oil from the crankpin led through a pipe carried within the hollow section of the connecting rod. A special arrangement for breathing and scavenging the crank compartment consisted of seven gauze covered ventilators on one side of the case and corresponding openings on the opposite side which communicated to a marine-type cowl.
The two water-jacketed carburetors were attached to the end cylinders at the water jacket flanges. These carburetors consisted of a barrel throttle, a main air regulator, a jet, and damping device; and a constant head gravity fuel feed reservoir. The carburetors and fuel feeding device were of unique design, this particular feeding device being unaffected by variation in altitude.
The lubricating system was a very complete and carefully worked-out design employing piston type oil pumps. The engine was equipped with a mechanical self-starter, and, Airplane Engine Encyclopedia dual ignition was provided by two Bosch ZH6 magnetos. The airplane engine, generally referred to as the 300-h.p, Maybach, developed 283 h.p. at 1400 r.p.m. and 302 h.p. at 1700 r.p.m. The bore was 165 mm. (6.5 in), the stroke 180 mm. (7.09 in.), and the total displacement 1411.62 cu. in. The compression ratio was 5.91, and the maximum brake mean effective pressure which occurred at 1000 r.p.m., was 123 lbs. per sq. in. The fuel consumption was reported to be .464 lbs. per h.p-hr., the oil consumption ,0223 lbs. per h.p-hr. The dry weight was said to be 921 lbs., and the water content of the engine 22 lbs. Fig. 311. The 30O.h.p. Maybach Engine.
The design was similar in many respects to the 2CX)-h.p. airship engine. The cylinder heads, which were cast from iron, received the screwed-in steel cylinder barrels, but the water jackets were separately machined inside and out to a very thin wall from steel forgings and fastened to the head by threads and by a packing nut at the lower end to the cylinder barrel. There were four vertical valves in each cylinder, with a port diameter of 48 mm. (1.89 in.), 30 degree seats, and a lift of .375 in. The valve ports were siareesed. The inlet valve opened 8 degrees early and closed 35 degrees late; the exhaust
The Mercedes airplane engines, which have been frequently referred to as the German-Daimler or Mercedes Daimler designs, were built at Stuttgart, and are probably the best known of any of the German makes. These engines came into prominence during 1913, and during the war were one of the standard types adopted by the Germans. Water cooled vertical engines of four, six, and eight cylinders were the types constructed.
The first Mercedes engine was a four-cylinder vertical water-cooled type rated at 50 h.p. The overhead valves were operated by push rods and rockers, and the timing gears were not enclosed. A similar design, rated 60 h.p. at 1350 r.p.m., had a 110 mm. (4.33 in.) bore, 140 mm. (5.51 in.) stroke, and 324.56 cu. in. total displacement.
Type E4F. The four-cylinder vertical Mercedes engine with 120 mm. (4.72 in.) and 140 mm. (5.51 in.) bore and stroke, and a total displacement of 385.64 cu. in., was rated at 70 h.p. The engine actually developed 60 h.p. at 1200 r.p.m. and 70 h.p. at about 1350 r.p.m., and was said to consume on an average .53 lbs. of fuel per h.p-hr. and .033 lbs. of oil per
Mercedes h.p-hr. The weight was reported to be 308 lbs., or 4.4 lbs. per rated h.p.
The cyhnders were originally cast in pairs from grey iron with water jackets integral. Later the jackets were made separately from sheet steel and welded in place. The connecting rods had "H" sections, and the pistons were made from pressed steel. Dual ignition was supplied by Bosch magnetos.
A similar four-cylinder vertical design of 140 mm. (5.51 in.) bore, 150 mm. (5.91 in.) stroke, and 563.68 cu. in. total displacement, developed normally 90 h.p. at 1200 r.p.m. and 100 h.p. at 1400 r.p.m. The fuel consumption was said to be .49 lbs. per h.p-hr., and the weight 400 lbs., or 4,44 lbs. per normal h.p.
F:g. 316. The Four-Cylinder Inverted Mercedes Engine.
Type J4L. A four-cylinder Mercedes engine, known as Type J4L, had a 160 mm. (6.3 in.) bore. 170 mm. (6.69 in.) stroke, and a total displacement of 834.16 cu. in. This engine was rated 120 h.p. at 1100 r.p.m., and said to weigh 660 lbs., or 5.5 lbs. per rated h.p. The consumption of fuel and oil was reported as .53 and .033 lbs. per h.p-hr., respectively. The cylinders were constructed in pairs from cast-iron, and one inlet and two exhaust valves, standing vertically in each cylinder head, were operated by means of push rods and rockers.
A four-cylinder engine, having the same rating and approximately the same weight as the J4L type, was designed principally for dirigible use. The bore was 175 mm, (6.89 in.), the stroke 165 mm. (6.5 in.), and the total displacement 969.4 cu. in.
Pig. 317. Exhaust Side of Mercedes 100-h.p. Engine.
Inverted Type. As a means of affording greater visibility to the pilot, a four-cylinder unit was built with Type E4F cylinders extending vertically downward. This engine was also said to develop 70 h.p. at 1400 r.p.m. Aside from the over-oiling which might possibly be anticipated with such an arrangement, the practical results obtained are identical with engines having cylinders placed above the crank compartment. For water circulation, the inverted cylinders offer the advantage of entering the cooled water from the radiator directly upon the combustion head which is the hottest part of the cylinder.
Type J8L. An eight-cylinder vertical engine, employing the same cylinders as the J4L type, was rated 240 h.p. at 1100 r.p.m. The total displacement was 1668.32 cu. in., and the weight was said to be 1250 lbs., or 5.22 lbs. per rated h.p. Another eight-cylinder engine, rated 240 h.p. at 1100 r. p.m., was said to weigh 1820 lbs., or 7.58 lbs. per rated h.p.
This engine was intended for dirigible use. The bore was 175 mm. (6.89 in.), the stroke 165 mm. (6.5 in.), and the total displacement 1938.8 cu. in. During recent years the Mercedes designs have been confined almost entirely to the six-cylinder vertical water-cooled Fig. 318. Inlet Side of Mercedes 100-h.p. Engine. types. One of the earlier six-cylinder engines, that developed 80 h.p. at 1200 r.p.m. and 90 h.p. at 1400 r.p.m., had a 105 mm. (4.13 in.) bore, 140 mm. (5.51 in.) stroke, and a total displacement of 442.86 cu. in. The fuel consumption was said to be .505 lbs. per h.p-hr.. and the total weight 312 lbs.
Type E6F. The type F,6F was one of the first Mercedes engines to employ an overhead camshaft and the valve gear which has proven so popular. This engine was rated at 100 h.p. and said to weigh 444 lbs. The bore was 120 mm. (4.72 in.), the stroke 140 mm. (5.51 in,), and the total displacement 578.46 cu. in. The fuel and oil consumption were reported as .53 and .033 lbs. per h.p-hr., respectively.
160-h.p. Model. The 160-h.p. Mercedes engines were used in large numbers by the Germans from the very beginning of the war. These were six-cylinder vertical water cooled engines of 140 mm. (5.51 in.) bore, 160 mm. (6.3 in.) stroke, and 901.32 cu. in. total displacement. The actual out-