Published on March 30th, 2018 | by Daniel Sherman Fernandez0
What makes the Porsche boxer engine tick? Watch the video
The first Porsche had a four-cylinder engine and it won over car fans, not only by its charming appearance, but also by its fast-paced character. The very first 356 prototype production number 1 raced a fast demonstration lap at the city street race in Innsbruck. Back then it still had a mid-engine; later in production, it was replaced by a rear-mounted engine. The engine in the 356 is an old acquaintance. It is based on the Volkswagen flat engine that was developed by the Porsche design office in the 1930s. After Innsbruck, it could no longer be held back. There is hardly a classic race the car has not won: the 24 Hours of Le Mans, the 1000 Kilometres of Buenos Aires, the Mille Miglia, Targa Florio, Carrera Panamericana. The Porsche 356 was always out at the front.
The Porsche boxer or flat configuration engines can be made approximately half the length of a straight configuration engines. Compared to ‘V’ engines boxers are not as tall, offering the ability to position mass lower in the vehicle’s chassis, but are wider.
All boxer engines feature low primary vibration as pairs of pistons are opposed and move in a way to cancel out each other’s momentum.
Like Vs boxers are more complex that straight engines, having 2 cylinder heads with associated head gaskets, exhaust manifolds etc., and double the number of camshafts, more complex camshaft chains or belts and more complex cooling.
Compared to Vs, boxer engines have a more complex crankshaft as they have a crank throw for each connecting rod. True V’s have pairs of rods sharing each crank throw.
The probable reason boxer or flat configurations are not used very often in modern cars is because a straight or V engines are almost always a better choice.
Many cars are now front wheel drive which work best with a compact, transversely mounted engine. A straight-4 or a V6 are much more suitable that a flat-4 or flat-6 in this configuration.
Longitudinal mounted engines are preferred for front-engine, rear wheel drive, the boxer engine’s lower mass probably does not provide enough advantage over the simpler straight-4 or V6.
Where boxer’s really do seem to work is in air-cooled rear-engined cars like the Porsche 911 and VW Karman Ghia (see below) where width is less of a concern, the engine must be a short as possible to avoid a large mass behind the rear axle, and the banks of cylinders are easier to cool as they are more widely spaced from each other.