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porsche hangout A Brief History On The Iconic Flat 6 Engine

The Flat 6 is one of the most unique-sounding engines in motorsport, and has been used by multiple brands throughout history. In order to experience a modern flat 6 engine, your only options are Subaru and Porsche. With Subaru retiring their EZ line of flat 6 engines in 2019, the 911 and GT4 are the only car’s still being made that have a flat 6 at their heart.

As the last of the breed, let’s take a look at the history of Porsche’s iconic flat 6.

The Mezger Flat Six

With the introduction of the Porsche 901 (later renamed the 911 due to legal disputes), Porsche moved from the VW-inspired flat 4 to the first full-blown Porsche flat 6. The man behind the design of the small, high performing air-cooled flat 6 was Hans Mezger.

Post-World War II Germany was no place for a large displacement engine, so Mezger opted to keep the displacement at just 1991ccs. To make up for performance, Mezger looked towards the other project he was working on at the time: the flat 8 753 race engine. He borrowed the 80mm bore 66m stroke, which allowed the bore to accommodate larger valves that would allow the engine to breathe better at high rpms.

The real genius of Mezger’s design was the 188mm space between the bores that would allow the engines to be easily bored for more performance in the future. The market-ready iteration of Mezgers engine weighed just 185kgs and put out a staggering 148 horsepower. This could only be beaten by cars with far larger engines, from the likes of Chevrolet and Jaguar.

The “Mezger Flat 6” continued to be developed by Porsche up until it was retired in 2004.

The M96, A Post-Mezger Flat 6

In the early 90s, Porsche was facing serious financial troubles. The 944 was not the sales hit Porsche had hoped for. Its replacement, the 968, piled on the financial problems. Porsche was facing down the barrel of a gun and needed something to help turn things around.

The decision was made to create a new engine: one that would offer similar performance and a cheaper production price for the 996 generation and the all-new model, the Boxster. So the M96 engine was born.

Most Porsche enthusiasts were not happy that Porsche made the decision to move away from the classic air-cooled formula. They were even more disappointed when they drove the M96-powered cars. Acceleration was dreadful compared to its air-cooled predecessor. The increased weight of the car, due to the cooling system, meant the cars were less nimble. The introduction of variable valve timing with VarioCam did little to improve the situation.

The M96 proved to be such a disastrous design for the range-topping Turbo and GT models. As a result, Porsche went back to the Mezger-designed engines and modified the design to accept water cooling.

The Modern Flat 6

The 997 generation introduced two new engines from Porsche. The M97 fixed many of the complaints that were raised about the M96 and added direct fuel injection for better performance. Porsche took what they learned from the M96 debacle. With the facelift of the 997, they introduced the first of the 9A1 engines in the form of the MA1. The 9A1 engine introduced Porsche’s new VarioCam Plus system: the 9A1 engine that forms the basis of all modern Porsche flat 6 engines.

Flat 6 Engines For Porsche Lovers

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