An Eight-cylindered Steam Engine
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A Striking New Power Unit from America. Rotary Inlet
Valve Supplying Eight Cylinders in a V-type Block. Part'
1,000 lb. Pressure, 2,000 r.p.m., Over 240 b.h.p.
A T a time when research in connection with steam engines is attracting great 'attention in this country, we receive information concerning a new American product of more than. usual importance. The concern responsible for this design is Baker Motors, Inc., 17, East 42nd Street? New York city; the parent company is General Syndicate, Inc.
This V-type eight-eylindered engine is designed to work at pressures varying between 100 lb. and 1,0043 lb. per sq. in. It develops 45 'n.h.p. at 150 lb. pressure and 400 r.p.m.; at 300 lb. pressure and 1,500 r.p.m. the output is 240 b.h.p.. Actually the engine will run up to 2,000 r.p.m. and can work at considerably higher pressures, giving more power.
A monobloe casting comprises the eight cylinders, their axes being set at an angle of 45 degrees to each other ; there are two banks of four cylinders ; the bore and stroke are 41. ins, and 5 ins. respectively. Between the banks is a tunnel housing a rotary valve ; in reality this forms a steam chest which rotates in a roller bearing at each cud. It runs at half crankshaft speed in the reverse direction and is driven by a chain. Steam passes along the valve and through ports to the cylinders. Exhaust steam is discharged through ports in the cylinder walls.
Owing to the use of roller bearings the clearance between the valve and its tunnel can be kept small, but to ensure that steam does not find its way along the outside of the rotating valve, special sealing rings are employed. Provision is made in the design of the valve-operating mechanism to permit of varying the lead, and, consequently, the compres
sion,in order to give the best performance over a wide range of speeds. The cut-off also can be varied.
The 4-in. crankshaft runs in five bearings ; there are four cihnkpins, on each of which operates a master connecting rod. Thus there • are four master rods for the cylinders in one bank and the other four rods articulate on the masters. The chain drive for the valve is entirely enclosed at the front end of the engine, as is also the oil pump for supplying the main bearings, big-ends, gudgeon pins, cylinders, etc.
In this country there is a more highly developed steamwagon industry than in any other part of the world. At the moment it is labouring under severe legislative handicaps. The way out of the impasse is thought by many to be by employing high-pressure engines.
We are indz■bted to our American cuntemporau Power for the accompanying illustrations.