The Brit kit that transforms classic 911 into a 12,000rpm monster

Back in 2023 Swindon Powertrain announced its four-valve cylinder head kits to fit the Porsche 911 964 and 993 M64 engine.

The company reached a milestone recently when it supplied its 100th kit, which is designed for use by specialist engine builders and requires the rest of the engine to be modified to withstand the extra power and revs. The standard M64 engine has two valves per cylinder, but the new heads open up the engine’s breathing to raise a 993’s redline from 6900rpm to as high as 12,000rpm.