The Volkswagen engine's flat four (opposing) design has proven itself in automotive, industrial and aerial applications as one of the most rugged and reliable made in the world today. The four-cycle, overhead valve engine has two pairs of cylinders horizontally opposed; it is attached to the transmission case by four bolts, and is easily removed for service.
The engine in the smaller (beetle) Volkswagens is capable of 60 hp. output, while that used in the larger (Fastback and Squareback) cars is rated at 65 hp. on the SAE scale. Both engines are of the same basic design as that of the original prototypes but are much more highly developed.
Because it is air-cooled, the VW engine is slightly noisier than a water-cooled power-plant of the same size due to the lack of a water jacket to provide a silencing function. In addition, air-cooled engines tend to be somewhat noisier because of clearances between parts. Higher operating temperatures of air-cooled engines require more room for expansion of parts. However, noise in the Volkswagen is damped by good insulation and the little that is present should serve to remind the Volkswagen driver that he has one of the most reliable and trouble-free engines made anywhere, anytime.Type 1 and 2 (Upright) Engine
The engines used in the type 1 and type 2 vehicles are known as "upright" engines, because of the configuration of the cooling system tins. Since the cooling fan, on these engines, is mounted on the generator shaft, the cooling system sheet metal is arranged in an upright fashion (most of it is above the engine and stands taller than the carburetor and generator).
Although the pancake and upright engines differ in the arrangement of their cooling systems, the engine block, the internal components and many of the external engine components are the same.Type 3 (Suitcase) Engine
The engine in the type 3 (Fastback and Squareback) series is similar to the type 1 and 2 engines, the main exception being the location of the cooling fan on the crankshaft rather than on the generator shaft. With the type 3 engine, there is no chance of cooling fan failure due to fan belt breakage, because there is no fan belt. If the generator belt should fail, the driver could drive some distance in daylight before running out of electricity for the ignition. In addition, the type 3 engine is slightly different in the location of the oil cooler and, of course, in the layout of the cooling ductwork.