An interesting development for 964 and 993 engines.

[Bill Douglas]

Swindon Powertrain has developed a 24-valve cylinder head kit for the 964 and 993 engines that rocks redesigned four-valve per-cylinder castings to unlock more horsepower and torque. In-house testing has revealed that peak flow has improved by 40% at the inlet and 60% at the exhaust. What’s more, Swindon’s cylinder head reduces weight by 3.5 kg (7.7 lbs) and allows applicable engines to rev all the way to 12,000 rpm.


https://www.carscoops.com/2023/10/swindon-creates-porsche-911-cylinder-head-that-allows-air-cooled-engines-to-rev-to-12000-rpm/

[Ian Comerford]

Swindon built the Tuthill 911K engine that runs to 11k revs. Assume this is the base kit

[Bill Douglas]

That's interesting.

If they are talking about 12,000rpm they sure would want a beautifully balanced crank and pistons.

[fanaudical]

Very cool!

[Dpmulvan]

Guaranteed I can’t afford it.

[Locker537]

Originally Posted by Dpmulvan

Guaranteed I can’t afford it.

"The British company’s complete M64 cylinder head kit is priced from £29,950 ($36,413)."

Gotta pay to play...

[Evan Fullerton]

Given that it’s ~$20k for Xtreme 2 valve heads, Pauter or Schrick billet rockers, new cams, billet valve covers etc.

Almost seems like a bargain.

[RocketJohn]

Do we know how much more horsepower?

[RSTarga]

Are they able to do that without watercooling the heads? Must be some exotic materials

[Ian Comerford]

I’m just glad they be done it……

[phelix]

A combination of metallurgy and manufacturing techniques?

[dw1]

Another article:

https://www.thedrive.com/news/air-cooled-porsche-911s-can-rev-to-12000-rpm-with-these-new-cylinder-heads

Amusingly (and realistically) this article points out the lack of price details and suggests the old saying: "if you have to ask, you can't afford it."

I certainly agree with the prior comments indicating the heads may enable the stratospheric revs, but I sure hope the engine's bottom end is up to the strain. But then, anyone buying these heads would surely have the rest of the motor "built and blueprinted".

[stownsen914]

Considering the price of 911 rebuilds and parts these days, honestly that price doesn't seem ridiculous.

[nospiners]

Its a pipe dream , but for the 1% !!! Most of us would be happy with a good running , all systems
working , no leaks 911 ...

[Ian Comerford]

[Ian Comerford]

[rswannabe]

Hmmmmmm, take a 3.6 and swap in Supertech’s 66mm stroke Supercrank, run the nascar bearings and gt3 rods and these heads and I bet 10-12k redline is there for the taking.

[phelix]

Wonder if there’s effectively a rev limit on a standard case?

[pkabush]

Interesting. I was hoping someone would post more info on how the Tuthill build spun to 11K
Sounds like a riot. Unfortunately, I’ll likely never know.

[David Inc.]

Wild that they don't comment on cooling. I wonder how they do it?