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The Villiers Engineering Co. Ltd.

Some Technical Details

This section includes a few notes and details of the mechanical and electrical systems that were used in Villiers engines. 

One of Villiers famous motorbike engines of the late 1920s was the 'Standard Sports'. It was a 172c.c. engine with cast iron piston, fixed cylinder head, twin exhaust pipes and variable ignition, which was fitted to all Villiers engines at that time. The 'Standard Sports' also included a large silencer that had 16 times the volume of the swept volume of the engine. It also had a drip feed lubricator. A higher performance engine was the 172c.c. 'Super Sports T.T.' which had an aluminium die-cast detachable head and flywheel magneto. It was also fitted with the Villiers patent lubrication system which had no moving parts. The quantity of oil supplied depended upon the engine load instead of engine speed. The crankshaft journals were drilled with four lateral ports, the outer pair of which, were placed to permit a small amount of the compressed gases in the crank chamber, to be forced out through grooves in the main bearing bushes, to a union on the front of the crank case and up into the oil tank of the engine. In this way pressure was built up in the space above the oil in the tank and the lubricant was forced up a vertical pipe into a flush-fitting drip feed. From there it flowed through a pipe and into the cylinder. In a similar way oil was also fed to the crankshaft bearings through separate passages and through the drilled crankshaft to the roller bearing.

Villiers produced simple and reliable engines, with few moving parts. One of the company's successful innovations was the flywheel magneto, in which the high tension voltage was generated within the flywheel casing, the only moving part being the flywheel itself. Magnets and pole pieces were attached to the inside of the flywheel and a voltage was induced in a stationary coil in the centre. This technique was extended to provide the low tension voltage for electric lighting and battery charging.

The flywheel magneto.

The whole arrangement was extremely reliable. Apart from the spark plug, the only item that needed occasional attention was the contact points in the contact breaker.

The points needed to be kept clean and the gap correctly set. Failure to maintain a sufficient gap led to overheating and considerable difficulty in starting.

The wiring diagram of the simple lighting set which did not include a battery. It produced an A.C. voltage to light the head lamp and tail lamp.

Due to the special winding of the coils, a rapid rise of voltage was obtained. This was almost constant over 25m.p.h.

The charging set rectified the A.C. voltage induced in the lighting coils by a commutator, which was carried on the flywheel.

A centrifugal cut-out was mounted on the flywheel to prevent the battery discharging through the lighting coils, when the flywheel was stationary. A Nife accumulator was used which needed to be topped up with distilled water instead of acid.

Care was required when doing this, as the liquid electrolyte contained caustic potash which would attack the hands or clothes.

The Villiers Mk.10 stationary engine.

The Mk. 10 Villiers stationary engine was a typical Villiers product. It was simple, neat and compact, with few moving parts. Because of this simplicity, Villiers engines were reliable and easy to maintain.

The engine included the Villiers flywheel magneto, with the engine cooling fan mounted on the outside of the flywheel.

Most of the parts were made in-house and additional parts were available for petrol-paraffin running.

The engine had a 50mm bore and a 50mm stroke. The total swept volume was 98c.c. and the engine could deliver 1h.p. at 2,000r.p.m., and 1.3h.p. at 3,000r.p.m. It was air-cooled and used an oil-wetted type of air filter.

The capacity of the fuel tank was 0.5 gallons and the lubricating oil sump held one pint. It was fitted with a Lodge spark plug and Villiers carburettor.

A drawing showing the parts that make up the Mk.10.

The Villiers Mark 3 engine.

The Villiers Mark 3 engine was introduced in 1920 and was one of the last engines made by the company before the introduction of the flywheel magneto. It used the conventional type of chain-driven magneto with horse-shoe magnets and a conventional flywheel.

The engine was designed to allow easy access to the various parts for servicing. The carburettor was attached almost at the top of the cylinder wall to allow access to the jet. The spark plug was moved to the top of the cylinder, to isolate it from the top cooling flange and it kept remarkably cool.

The inlet gas was led through an induction passage, cast into the cylinder assembly. This arrangement avoided condensation and gave greater efficiency because the gas was warmed on its way to the crank case. Like many Villiers engines, it included double silencers and was very quiet in operation.

Another view of the Mark 3.    

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