--- title: "Air-Cooled Porsche 911s Can Rev to 12,000 RPM With These New Cylinder Heads" description: "Classic air-cooled Porsche 911 sports cars like the 964 and 993 can now upgrade to ultra high-revving cylinder heads." date: "2023-10-06" modified: "2023-10-06" authors: - name: "James Gilboy" job_title: "Contributing Writer" link: "https://www.thedrive.com/authors/james-gilboy" url: "https://www.thedrive.com/news/air-cooled-porsche-911s-can-rev-to-12000-rpm-with-these-new-cylinder-heads" categories: - "News" - "News by Brand" - "Porsche News" tags: - "911" - "porsche" - "sports car" --- # Air-Cooled Porsche 911s Can Rev to 12,000 RPM With These New Cylinder Heads ![Porsche 911 (993) in red next to a disassembled cylinder head]() *\Swindon Powertrain, Porsche\* Some say there's no replacement for displacement; I say there's no replacement for revs. Low-end torque is a boon, but it has nothing on a tachometer that plays the floor-is-lava with the 7,000 rpm mark. And if you own an [air-cooled Porsche 911](), you can now play that game with a new set of four-valve cylinder heads that are built for a mystical 12,000 rpm. Such heads are a new offering from [Swindon Powertrain](), the exclusive supplier of the British Touring Car Championship's race engines, which also appears to have had a hand in the canceled [Jaguar C-X75]() supercar. The heads are built to fit the [Porsche]() M64, the family of air-cooled flat-sixes used in the final two generations of air-cooled 911, the [964]() and 993. From the factory, they're just single-overhead-cam three-valve units, or about on par with that you'd find in a minivan of the time. These are still single-cam too, but they're a world apart from the stock engine. ![]() ![]() ![]() ![]() ![]() For starters, they now feature four valves per cylinder, enhancing flow. They raise compression from about 11:1 according to [964UK.com]() to 11.5:1, with 12:1 being available if you buy the right pistons. They're 7.7 pounds lighter than the stock heads too, which ought to improve handling. Better still, they're a perfect fit with the stock engine's cam drive, oiling system, valve covers, crankcases, and even exhaust. They include an installation manual and have also been designed to accommodate a 997 GT3 intake and 718 ignition coils if you're going the resto-mod route. If you are, Swindon Powertrain also offers power steering drive compatibility, CNC porting, a carbon fiber fan shroud, and any cam profile your heart could desire. ![Porsche 911 Carrera 4S (993) in red]() *Porsche 911 Carrera 4S (993). *Porsche** Of course, it's sometimes said that [Porsche]()'s air-cooled engines are the most expensive way to make horsepower, and that appears to be the case here. The starting price for these heads isn't listed on Swindon Powertrain's website, and you know how the saying goes: If you have to ask, you can't afford it. That said, given the price of air-cooled 911s these days, it's probably of no consequence to their owners—especially the ones who can afford to chase every last horsepower gain. *Got a tip or question for the author? You can reach them here: james@thedrive.com* ## Author James is a former staff writer for The Drive. He has changed the conversation around electrification, debunked misinformation online, and become a prominent hunter of what he calls "automotive cryptids." ### Author social links [Instagram]()