British company lets your old Porsche 911 rev up to 12,000 rpm

For the air-cooled 911s, because those are the real ones

Ask a self-proclaimed Porsche expert what a real 911 entails. If he doesn't mention an air-cooled engine within 3.5 seconds, it's finished. The M64 engine lasted until 1998 and is part of the 964 and 993 generations. The 3.6-liter six-cylinder boxer engine went up to 7,000 rpm (in the GT2 and Cup version). Now, thanks to a new set of cylinder heads, the boxer engine can continue up to 12,000 rpm.

Swindon Powertrain only supplies the upgrade to Porsches with a naturally aspirated engine. What exactly do they do? Well, double the number of valves. There are two valves on each cylinder as standard; for the cylinder heads from Swindon Powertrain there are four. In addition to the higher speed, the adjustment allows more air to enter the combustion chamber and lighter valve springs ensure less tension on the rocker arms.

Despite doubling the number of valves, the package weighs 3.5 kilos less than the original. This is because each valve is made of titanium and is slightly smaller than the original. Before you try to drive your modified old Porsche 911 towards 12,000 rpm, you still need an intake manifold from a 997 GT3 and ignition coils from a 718.

Swindon Powertrain says power and torque are 'significantly improving'. But the company cannot say how many extra horsepower and newton meters you get. "After all, there are many more components that have an effect on the power," manager Raphaël Caillé told TopGear Netherlands. What he can report is that the engine can breathe 40 percent more air.

The price of the Swindon Powertrain package

Shifting the red line is not cheap. The British company charges £35,940 for the package of parts that helps your old Porsche 911 reach 12,000 rpm. That is approximately 41,000 euros. For that, you get all the non-OEM Porsche parts you need to upgrade the M64 engine to four valves per cylinder. Then you still have to install the package.