The Volkswagen Air-cooled engine looks quite like virtually no other, mainly because the business end is only the lower third of the engine assembly, with the electrics, carburation and cooling taking most of the space above the coverplate (tinware). This section is designed as an introduction to the engine layout and to assist in the location of engine components.
HOW THE ENGINE WORKS - INTRODUCTION
The Volkswagen engine is an air-cooled horizontally opposed flat four cylinder design, commonly known as a "Boxer Engine". The engine is a conventional Four-Cycle Engine. This section gives a general overview of how the engine works. It outlines the role of all the major engine components and how they function together. There are subsequent links to explain the functions of individual components. Some sections contain animations to help illustrate the working of a component.
The bottom end consists of a short crankshaft and camshaft located between the two halves of a magnesium alloy crankcase. The flywheel is located on the front of the crankshaft.
The camshaft operates the valve push rods. The oil pump is also driven by the camshaft, providing oil for the lubrication system. The distributor is driven by a shaft engaged in a worm gear on the crankshaft. The fuel pump is subsequently driven by the distributor shaft.
The pistons move back and forth in four separately mounted, finned cylinder barrels. Each pair of cylinders has a common cylinder head containing the valves and rocker gear operated by the pushrods (valve train).
The engine's air-fuel mixture is supplied and regulated by a carburettor which is subsequently ignited by a conventional ignition system and distributor. A fan-belt from the crankshaft pulley drives the generator / alternator and the engine's cooling fan.