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Villiers General Specification Sheets Mk 20 HS
The Villiers General Specification Sheets Mk 20 HS is a comprehensive technical document that provides detailed information on the design, construction, and operation of the Villiers Mk 20 HS engine. This engine is a compact and lightweight two-stroke single-cylinder air-cooled petrol engine that is commonly used in a variety of applications, including motorcycles, scooters, and small generators.
Design and Construction
The Villiers Mk 20 HS engine features a simple and robust design that is easy to maintain and repair. The engine has a cast iron cylinder with a bore of 54mm and a stroke of 54mm, resulting in a displacement of 197cc. The piston is made of aluminum and features a single piston ring. The connecting rod is made of forged steel and is fitted with a bronze bush at the small end. The crankshaft is made of hardened and ground steel and runs on two ball bearings.
The engine is equipped with a rotary valve for induction and exhaust. The rotary valve is made of aluminum and is driven by a gear on the crankshaft. The valve is timed to open and close the intake and exhaust ports at the appropriate times in the engine cycle.
The Villiers Mk 20 HS engine is lubricated by a mixture of oil and petrol. The oil is mixed with the petrol in a ratio of 25:1. The oil-petrol mixture is then drawn into the engine crankcase by the piston as it moves down the cylinder. The oil-petrol mixture lubricates the crankshaft, connecting rod, and piston as they move.
The Villiers Mk 20 HS engine is cooled by air. The cooling fins on the cylinder and head dissipate heat from the engine as it runs. The engine is also equipped with a flywheel that helps to dissipate heat and reduce vibration.
Operation
The Villiers Mk 20 HS engine is a two-stroke engine, which means that it completes one power cycle in two strokes of the piston. The power cycle begins when the piston moves down the cylinder and draws in a mixture of air and petrol through the intake port. The intake port is then closed by the rotary valve, and the piston moves up the cylinder, compressing the air-petrol mixture. When the piston reaches the top of the cylinder, the spark plug ignites the air-petrol mixture, causing it to burn and expand. The expanding gases push the piston down the cylinder, generating power. The exhaust port is then opened by the rotary valve, and the piston moves up the cylinder, pushing the exhaust gases out of the engine.
The Villiers Mk 20 HS engine is equipped with a centrifugal clutch that engages when the engine reaches a certain speed. The clutch engages the engine to the transmission, which then drives the wheels of the motorcycle, scooter, or other vehicle.
The Villiers Mk 20 HS engine is a reliable and efficient engine that is well-suited for a variety of applications. It is easy to maintain and repair, and it provides good performance and fuel economy.
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Villiers general specification Sheets Mk 20 HS
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