Porsche have always been at the forefront of automotive technology. Ferdinand Porsche was easily one of the greatest engineering minds to have come out of Germany and the company has followed in his footsteps throughout its existence. The legendary motorsport success and the 911 have gone on to define Porsche as a technological powerhouse. However, Porsche’s brush with the aviation industry did not really help it reach these heights of engineering superiority.
Interestingly, Ferdinand Porsche himself had more than his fair share of success designing aircraft engine. In 1909, Ferdinand won a 2000 km touring car race in a Prinz Heinrich car. He saw potential in the 80 hp, 4 cylinder engine and used a development of that engine to power the Taube monoplane, the work of Austrian aviation pioneer, Igo Etrich. Following this, Porsche managed Austro-Daimler, where he designed a number of 4, 6 and 12 cylinder aircraft engines, with the most powerful ones producing close to 400 hp. Soon after founding his namesake engineering design firm in Stuttgart, Ferdinand built the Type 55 aircraft engine, which put out an impressive 1000 hp: and followed it up with the Types 70 and 72, with 16 and 32 cylinders. He was also tasked with designing the Mercedes-Benz T 80, a potentially land speed record-breaking race car. This car featured a mind-boggling 45-litre, 3500hp Daimler-Benz-DB-603 bomber engine. Its run was expected to break the 600 kph barrier in 1939, but the Second World War put an end to proceedings.
Schematic of the Porsche PFM 3200 air-cooled flat six engine. Source
These brushes with aircraft engines continued under Ferry Porsche as well. In 1955, Porsche introduced the Type 678 with power ranging from 65 hp to 75 hp. This engine was the first German post-war engine and was used in aircraft such as the Rheinflug RW-3, the first German small aircraft to be built after Second World War, or in the Elster, which the Bonn-based engineer Alfons Pützer designed on behalf of the newly founded German Federal Armed Forces.
By the late 70s however, a new trend emerged of the light sports aircraft being powered by variations of the 911’s flat six motor. This made sense because the flat six was reliable and air cooled. Also, it had a high output while using comparatively less amount of premium fuel. This piqued the interest of the engineers at Weissach in the early 80s, who decided to come up with their own variation of a 911 flat six derived aeroplane engine. The project was headed by Peter Schutz, the then CEO of Porsche, who is better known for his decision to not discontinue the 911 in favour of the transaxle 924 and 928.
The flat six PFM 3200 inside the nose of a Mooney M20L. Source
This design added dual ignition, a second alternator, a spur gear drive for the camshaft to make the engine suitable for light propeller-driven aircraft. It was called the PFM 3200 and had a higher operating speed as compared to older designs. This meant that the engine was smoother than earlier models, and because it used a muffler, was quieter as well. The 3.2-litre engine that was sourced from the period Porsche 911 Carerra produced about 210 hp in the naturally aspirated N-series, while the turbocharged T-series produced about 240 hp. This was roughly twice the horsepower of a conventional lower-rpm design of the same size. Another unique feature was a single throttle control, replace the standard throttle/prop/mixture setups of more conventional designs.
Porsche PFM 3200 First Flight. Source
While the engine received all necessary clearances by 1985, the project was beset with troubles. The engine was way more expensive than models already available, was extremely complex and also heavier than its competition. The single-engine market also faced a massive downturn around this time, further hurting the Porsche PFM 3200s chances. The oil crisis had also subsided by this time, which meant that it did not make sense for owners of existing small aircrafts to switch to the more efficient Porsche motors. By 1991, when production ended, the project had cost roughly $75 million and just 80 units had been delivered. These found homes in aeroplanes like the Extra 330, Mooney M20L, Socata TB-16, Robin DR400, Ruschmeyer MF-85, among others.
In 1986 pilots Michael Schultz and Hans Kampik circumnavigated the world with the Porsche PFM 3200. Source.
While the story of the Porsche PFM 3200 does not have a happy ending, it does go to showcase the strong culture of innovation and brilliance that has come to define the Porsche brand. The company found an outlet for their creative juices to flow and everyone from the CEO onwards were a part of what was essentially a side project. This work ethic is one of the primary reasons Porsche is one of the foremost names in the automotive world of the 21st century.