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Show fXPUKilON x POWER PLANT Gives Lucid Account of Engine Construction and Its Assembly. The $larmon enRine was given the "once over by W. lv. Lovering the other d&y. Here is what he said: "An extensive use of aluminum is one of the .striking features of the Alarmon rppine, which is drslgrned and constructed in Marrriqn shop.. Aluminum makes this r-r.gine Mfjhi in weight, very strong and rigid, and witli a high degree of heat conductivity, allowing perfect cooling. Instead of using cast-iron cylinder? bolted to a crankcase, the cylinder block is integral with the crankcase and Is of a single aluminum castmg. which extendu to the center line of the crankshaft. The rr.per part of the casting is cored out to receive six cast -iron cylinder sleeves, giving free water circulation around eacn cylinder. "This large aluminum casting is the main structural member of the engine, urrying the supports by which It is fastened to the frame. "The Marmon 34 single-phase crank-case crank-case and cylinder block casting is of extraordinary depth as compared with conventional design, and results in an engine of exceptionally sturdy construction construc-tion and light weight. The engine is six -cylinder, vertical, bore Z inches, stroke o'r inches, valve-in -head type. Tot displacement of the six cylinders 7of).(3 inches and standard horsepower Wratfng, 33.75. The engine weighs about T 860 pounds, while engines of conventional design, of the same size and power, weigh from 1000' to 1100 pounds. This light weight of the power plant allows the use of more flexible front springs and materially affects the riding qualities of the car. "The crankshaft runs on four main hearings, and is put in standing and running run-ning balance. Before the crankshaft end of the connecting rod is split to receive the bronze backed bearings, the' inside surface is ground to the exact size of the bearing. The camshaft is placed conventionally con-ventionally and runs on four bearings. The camshaft and cams are integral a one-piece forging. "The cast-iron firing head is a striking example of the manner in which Marmon Mar-mon engineers have made one piece serve functions which, in conventional design, require" the use of several parts. It is bolted to the top of the aluminum cylinder cylin-der casting and acts as a clamp oh the 'ylinder sleeves. Fn It there are three series of passageways; (1) for intake gases, '(2) for exhaust gases, (3) for the water JacUet around valves. Tn addition, this header carries the spark plugs, the valves., valve rocker arm shaft and rockers, rock-ers, intake and exhaust manifolds, and water outlet connections. "The, valves are located side by side in the caat-Iron cylinder head, each with two springs: the Inlet water-jacketed manifold is quite short, allowing for a high mounting of the carburetor, facilitating facili-tating carburetlon by reducing condensation. condensa-tion. An aluminum cap fastens over the top of the engine, enclosing the valve mechanism and giving the engine an extremely ex-tremely clean appearance. Oil vapor rising ris-ing from the crankcase Is held within tills cap and lubricates the valve push rod ends. "Automatic force feed lubrication of the engine is a Marmon feature. This system, sys-tem, whereby oil is fed to the bearings under pressure through a hollow crankshaft, crank-shaft, was used in the first Marmon car, built in 1902. It has been improved and defrped until now ft is the most perfect of oiling system. This system of oiling is used on the leading foreign makes and is coming into very extensive use amojip high-priced American cars. fjJollowing the Introduction and development- of the Marmon design. 'nJc- oil is kept at a level well above the TUppet guide bearings so that the rollers, pins, bottom end of push rods and guides are submerged in oil. The cylinder walls are also amply lubricated by oil, thrown off by the movement of the cranks. The oil pump is of the gear type, located outside the engine case, driven from rear end of camshaft." |