Swindon Powertrain Sells 100 M64 Cylinder Head Kits
Swindon Powertrain, a leading designer and manufacturer of high-performance road and race engines and components, has marked a major milestone with the sale of 100 M64 Cylinder Head Kits. The company supplies this 24-valve Porsche 911 engine upgrade to specialists and builders such as Thornley Kelham. The kit allows 964 and 993-generation Porsche 911 engines to rev to 12,000rpm.
Swindon Powertrain launched the M64 Cylinder Head Kit at the end of 2023. The retrofit package transforms the M64 air-cooled flat-six engine by increasing power and torque while cutting weight by 3.5kg compared with the standard setup. Swindon designed the upgrade for fast road, track, and race use. The kit replaces the original two-valve-per-cylinder layout with a 24-valve architecture, which significantly improves breathing efficiency. With four valves per cylinder, the kit delivers 40 per cent more peak flow than the standard 993 setup.
Swindon Powertrain casts the cylinder heads in the UK using aerospace-grade A356 aluminium. The company then CNC-machines them in-house at its Wiltshire facilities. After assembly, Swindon ships the kits to engine builders across Europe and worldwide, including the USA, Japan and Australia, for use in road and track Porsche 911 builds. Cotswolds-based restoration and modification specialist Thornley Kelham chose the heads for its limited-edition Porsche 911 European RS model. The company will produce only 15 cars and will offer customers two 24V options: a 3.6-litre, 380bhp+ unit producing 290lb-ft of torque with a 10,000rpm rev limit, or a 4.0-litre engine producing 425bhp+, 325lb-ft of torque and a 9,000rpm rev limit.
“Relying on low-flow, two-valve per cylinder architectures, the M64 air-cooled engines typically have restricted air flow into the combustion chamber, while the need for heavier springs stresses the rockers and limits rpm,” explains Sylvain Rubio, technical director at Swindon Powertrain. “Our M64 Cylinder Head Kit is helping deliver more power and performance to a new generation of upgraded Porsche 964 and 993 models, benefitting from the latest materials and the finest of CNC machining tolerances.”
The comprehensive M64 kit also includes titanium inlet and exhaust valves with springs, caps, collets, shims, finger followers and shafts, as well as camshafts, cam covers and timing drive input.
“We’re proud to be helping so many engine builders and 911 enthusiasts around the world unlock substantial extra power and torque to create truly standout builds with this high-revving upgrade,” adds Raphaël Caillé, managing director at Swindon Powertrain. “Pushing the boundaries of engineering – often beyond what seems conceivable – is a challenge we thrive on. We’re never content to stand still, so expect further high-performance developments set to be announced soon.”
Those developments include a new flat-eight engine. In late 2025, Runge Sportscars announced that it was working with Swindon Powertrain to develop a 5.3-litre, 32-valve, four-cam, air-cooled engine.