Building a 993 or 964 restomod? This is for you...
Swindon Powertrain promises 'transformative' performance from new 24-valve cylinder head kit
Swindon Powertrain has been in the news of late as a partner with Caterham on its EV project. But its history stretches back more than half a century now, with its roots firmly in making very racy engines for both motorsport and road use (like the 250hp Seven JPE, appropriately enough). Its latest creation is a welcome nod to that tradition while also showing what modern technology and manufacturing can achieve. It’s a 24-valve head for the last of the air-cooled Porsche 911s, the 964 and 993.
As well as being a beautiful thing to look at, it brings significant performance gains to the old flat-sixes. Given the fashion for restomodding old 911s shows no signs of abating, it feels like a good time to introduce what’s officially known as the M64 Cylinder Head Kit: keep air-cooled loveliness, introduce a whole new world of performance and possibilities.
A two-valve-per-cylinder head on any car has its limits, but for the 964 and 993 it was very old-school architecture. It meant a reduced valve area and low flow, ergo less air in the combustion chamber - and so a restriction on the power that could be achieved. They were big valves, too, and big valves need big springs, which are heavier, and won’t want to rev so high.
The M64 is intended to solve these issues. It’s made from A356 grade aluminium with titanium valves and saves 3.5kg over the regular heads in a 993. Swindon says flow improves in the 24-valve head over the standard 12-valve by 40 per cent on the inlet side and 66 per cent on the exhaust. Somewhat predictably, it reckons there are ‘substantial’ increases in both power and torque. Best of all is what this new head can do for revs, the overhauled valvetrain permitting up to 12,000rpm if somebody were inclined to embark on a very serious engine rebuild.
Swindon can help with that, of course, with pistons, inlet porting and bespoke cam profiles on offer. Or it’s fully compatible with the regular 943 and 993 engine as is. No changes are required for the lubrication system, cam chain drive or exhaust, regardless of engine size.
This sort of engineering doesn’t come cheap - the M64 Cylinder Head Kit is £30k plus taxes - but you only need to look at the lengths people are going to in the restomod space to see where the demand might come from. Who wouldn’t, if they could afford it, want a revvier, more powerful, more exotic flat-six in the back of their classic Porsche 911? “Using the latest innovations in materials alongside CNC machining to F1 tolerance standards, our cylinder heads transform an air-cooled engine. The improved breathing and ability to rev, unleash the potential to experience your 911 like never before” said Swindon Powertrain MD Raphaël Caillé. Good, right? And, really, it’d be rude to stop at just the very best cylinder head a 993 has ever seen once you’ve made the leap - might as well crack on with the full road racer transformation. This Turqoise Carrera 2 looks like the perfect candidate…
As suggested, you would need to be going for a full testimony to make it economically worthwhile. And unless that same turquoise 993 has had a boatload of recent engine work I’d suggest that the whole engine would need a refresh, or perhaps updated rods, pistons etc so that £30k plus taxes plus fitting will soon increase massively.
I stand to be corrected of course…
t, there are some pros and cons to each but old cars are largely a pain in the backside and compromised in many ways, truth is somewhere between these polar opposites I expect. Sure they are lovely but I wold take a nice new 992, prefer how it looks to be honest, which is unpopular and I quite like the 993/964 but I cant imagine how it would live up to the hype, experience with a 944 S2 hasnt helped in that regard of old Porsches.
Not sure how the 992 is so unappealing ? be interesting to drive both back to back, bet if we are actually honest and objective the new car would be way better in every way.
Reverence for old stuff is probably why religions start, and cults, and 911s do seem to have got a bit like that.
t, there are some pros and cons to each but old cars are largely a pain in the backside and compromised in many ways, truth is somewhere between these polar opposites I expect. Sure they are lovely but I wold take a nice new 992, prefer how it looks to be honest, which is unpopular and I quite like the 993/964 but I cant imagine how it would live up to the hype, experience with a 944 S2 hasnt helped in that regard of old Porsches.
Not sure how the 992 is so unappealing ? be interesting to drive both back to back, bet if we are actually honest and objective the new car would be way better in every way.
Reverence for old stuff is probably why religions start, and cults, and 911s do seem to have got a bit like that.
You need both.
For me, the NA pre 964 models are really lovely things.
t, there are some pros and cons to each but old cars are largely a pain in the backside and compromised in many ways, truth is somewhere between these polar opposites I expect. Sure they are lovely but I wold take a nice new 992, prefer how it looks to be honest, which is unpopular and I quite like the 993/964 but I cant imagine how it would live up to the hype, experience with a 944 S2 hasnt helped in that regard of old Porsches.
Not sure how the 992 is so unappealing ? be interesting to drive both back to back, bet if we are actually honest and objective the new car would be way better in every way.
Reverence for old stuff is probably why religions start, and cults, and 911s do seem to have got a bit like that.
You need both.
Does seem strange to choose new vs old, I dont think you can distill it down into being that simple, just pick what you fancy and dont feel the need to slag the other options off or rule them out completely. Like all the folk saying they will never, ever drive an EV, I dont want one right now but not ruling it out as dont want to do an embarrassing climb down at some point, seen it happen.
Wont be spending 30 grand on some heads any time soon, but who knows what life throws at you, times and circumstances change so what seems impossible and alien now may become a possibility down the line, unlikely but glad a British engineering company is making cool stuff like that, good luck to them !
I also agree that -and that is incredibly surprising- the 996 seems to be aging better than the 993.
Nevertheless, nice idea and the costs are plausible for what are basically going to be prototype volumes.
More in-depth info on the design would be interesting.
What impressed most was the the diminutive size of them. A 992 is of a size where it’s genuinely into GT territory - which is fine as long as you’re ok with that.
It’s great that these heads are available at all, notwithstanding the price.
To me the 911 peaked at the 997 as the the 991 & 992, designed from the outset for hybridisation, are just too big & heavy for a car without four seats which are useable for adults.
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