Swindon Powertrain has reached a remarkable milestone with the sale of 100 units of its M64 Cylinder Head Kits, a high-performance upgrade for Porsche 964 and 993 engines. Supplied to engine builders and specialists including Thornley Kelham, the kit transforms the M64 air-cooled flat-six by replacing the standard two-valve layout with a 24-valve architecture, enabling engines to rev up to 12,000rpm.
Launched at the end of 2023, the retrofit kit delivers significant gains in both power and torque while shaving 3.5kg off the original engine weight. With four valves per cylinder, peak airflow is increased by 40 per cent compared to the standard 993, enhancing breathing efficiency for fast road, track, and race applications.
Each cylinder head is cast in the UK from aerospace-grade A356 aluminium before being CNC-machined in-house at Swindon Powertrain’s Wiltshire facility. The finished kits have been shipped worldwide to engine builders in the USA, Japan, Australia, and across Europe. Notably, Cotswolds-based restoration and modification specialist Thornley Kelham has integrated the heads into its limited-edition Porsche 911 European RS, offering customers a choice between a 3.6-litre, 380bhp+ unit with 10,000rpm limit, or a 4.0-litre, 425bhp+ unit capped at 9,000rpm.
“Relying on low-flow, two-valve per cylinder architectures, the M64 air-cooled engines typically have restricted airflow into the combustion chamber, while heavier springs stress the rockers and limit rpm,” explains Sylvain Rubio, technical director at Swindon Powertrain. “Our M64 Cylinder Head Kit delivers more power and performance to upgraded 964 and 993 models, benefiting from advanced materials and precise CNC machining tolerances.”
The comprehensive kit includes titanium inlet and exhaust valves, springs, caps, collets, shims, finger followers, shafts, camshafts, cam covers, and timing drive input, offering a complete high-performance solution for enthusiasts seeking maximum engine potential.
Raphaël Caillé, managing director at Swindon Powertrain, adds, “We’re proud to help engine builders and 911 enthusiasts unlock substantial extra power and torque, creating standout builds. Pushing the boundaries of engineering is a challenge we thrive on, and further high-performance developments are on the horizon.”
Among these developments is a collaboration with Runge Sportscars to develop a 5.3-litre, 32-valve, four-cam, air-cooled flat-eight engine, set to push air-cooled performance to unprecedented levels.
