The best drives aren't always the fastest ones
In the hills between nostalgia and innovation, Singer Vehicle Design and Cosworth have quietly answered a question that haunts every restoration: not how much power can be recovered, but what kind of power is worth having. Their new 4.0-liter flat-six — 420 horsepower, variable valve timing, a torque curve smoothed into something almost conversational — represents fifteen years of collaboration distilled into a single philosophical statement about what driving should feel like. It is not the fastest engine Singer has built, nor the most extreme, but it may be the most honest.
- After fifteen years of partnership, Singer and Cosworth are no longer proving they can rebuild a Porsche flat-six — they are arguing about what that engine should fundamentally be.
- The introduction of variable valve timing, a first for any Singer restoration, disrupts the assumption that air-cooled purity and modern engineering must remain strangers.
- A hybrid cooling architecture — water-cooled heads married to air-cooled cylinders — borrows hard lessons from Singer's 710-horsepower DLS Turbo program and redirects them toward accessibility rather than extremity.
- The optional six-speed manual with a tall shifter and visible linkage is a provocation: Singer is insisting that mechanical transparency is not a compromise but a destination.
- With pricing expected to exceed one million dollars, the engine lands not as a mass-market solution but as a proof that the pursuit of driving pleasure, taken seriously enough, becomes its own kind of luxury.
Singer Vehicle Design, the Southern California restoration house that has spent fifteen years collaborating with Cosworth on Porsche's classic air-cooled flat-six, has unveiled what both companies are calling their most refined engine yet. The new 4.0-liter boxer produces 420 horsepower — but the number is almost beside the point.
The partnership began in 2011 with three engine variants ranging from 300 to 400 horsepower. Those were proof-of-concept years, Singer and Cosworth learning to honor the original architecture while reimagining it from within. The new M64 represents a different kind of ambition. It features a revised four-valve cylinder head, an entirely new combustion chamber, redesigned intake and exhaust systems, and — for the first time in any Singer restoration — variable valve timing. That last detail changes everything: the engine breathes more easily at low speeds, pulls harder at high revs, and delivers a flatter, more linear torque curve across the middle range where most driving actually lives.
The cooling system is technically novel as well. Singer has paired water-cooled cylinder heads with air-cooled cylinders and an electric fan, applying lessons absorbed from the company's extreme DLS Turbo program — a 710-horsepower, 9,000-rpm exercise in a completely different philosophy. This new engine points the other direction: toward pleasure, not spectacle.
To encourage drivers to explore the flat-six's 8,000-rpm ceiling, Singer offers an optimized six-speed manual transmission with an optional tall shifter and visible linkage — a choice that makes the mechanical connection between hand and engine something you can actually watch. A titanium exhaust gives the boxer its voice without restriction, treating sound as engineering rather than afterthought.
Pricing hasn't been announced, but Singer's recent restorations have sold for well over a million dollars. This one will almost certainly follow. It is a car built on the conviction that the best drives are not always the fastest — and that pleasure, pursued with enough seriousness, becomes worth almost any price.
Singer Vehicle Design, the Southern California restoration house that has spent decades taking 1990s Porsche 911s apart and reassembling them into something altogether different, has spent the last fifteen years working with Cosworth, the legendary engine manufacturer, to do the same thing to the air-cooled flat-six that sits behind the driver. Now the two companies have unveiled what they're calling their most refined collaboration yet: a 4.0-liter boxer engine producing 420 horsepower, paired with engineering choices that prioritize how the car feels to drive rather than how many numbers it can post on a dyno.
The partnership began in 2011 with three variants of Porsche's classic air-cooled six-cylinder. There was a 300-horsepower Touring version, a 380-horsepower Sport model, and a 400-horsepower Cup engine available in 3.9 and 4.0-liter displacements. Those were solid numbers for a restored engine, but they were also, in a sense, a proof of concept. Singer and Cosworth were learning how to work together, how to honor the original architecture while fundamentally reimagining it.
The new M64 represents a leap forward in that conversation. The engine features a revised four-valve cylinder head, variable valve timing—a first for any Singer-restored motor—a redesigned combustion chamber, and entirely new intake and exhaust systems. The variable timing alone changes the character of the engine across its entire operating range. At low speeds, where most driving actually happens, the engine breathes more easily. At high revolutions, it makes more power. Across the middle, the torque curve flattens out, becoming more linear, more predictable, more rewarding to explore.
There's also something technically novel happening with the cooling system. Singer has paired water-cooled cylinder heads with air-cooled cylinders and an electric fan, borrowing lessons learned from the company's DLS Turbo program—a separate, more extreme project that produced 710 horsepower and chased 9,000 rpm. That was a different philosophy entirely. This new engine is something else: a distillation of what Singer has learned, applied toward a different goal.
Twenty horsepower more than what the company was announcing fifteen years ago might not sound like much. But Singer's argument is that the real story isn't in the peak number. It's in what the engine does across the full range of motion. The flat-six can now exceed 8,000 rpm, and to encourage drivers to actually explore that territory, Singer offers an optimized six-speed manual transmission that sends power to the rear wheels. There's even an option for a tall shifter with visible linkage, a choice that seems almost perverse in its commitment to mechanical honesty—you can watch the gears change, feel the connection between your hand and the engine's work.
A new titanium exhaust system completes the picture, giving the boxer six its characteristic voice without restriction. The sound, in other words, is part of the engineering, not an afterthought.
As for price, Singer hasn't released a figure, but recent examples of the company's work have sold for well over a million dollars. This new engine, paired with a comprehensively restored 964 chassis, will almost certainly follow that trajectory. It's a car built for someone who understands that the best drives aren't always the fastest ones—that there's a difference between power and pleasure, and that the latter, when done right, is worth almost any price.
Citas Notables
The new engine represents the first Singer restoration incorporating variable valve timing, optimizing low-speed drivability, high-RPM power, and a more linear torque curve across the full operating range.— Singer Vehicle Design
The engine can exceed 8,000 RPM, and an optimized six-speed manual transmission is available to encourage drivers to explore that range.— Singer Vehicle Design
La Conversación del Hearth Otra perspectiva de la historia
Why does a company that could make 500 horsepower choose to stop at 420?
Because Singer isn't trying to win a benchmark test. They're trying to make you want to drive the car at eight in the morning on a road with no traffic, just to feel what it does.
But isn't more power always better?
Not if it comes at the cost of how the engine behaves when you're actually using it. A flat torque curve across a wide RPM range means the car responds the same way whether you're at 3,000 or 7,500 revolutions. That's harder to engineer than just bolting on a turbo.
What's the significance of variable valve timing on a restored engine?
It's the first time Singer has done it. It means they're not just preserving the original design—they're willing to add modern technology where it genuinely improves the experience. The variable timing optimizes low-speed drivability and high-RPM power simultaneously, which the original fixed timing couldn't do.
Why pair water-cooled heads with air-cooled cylinders?
It's a compromise that works. The heads run cooler and more efficiently, but you keep the air-cooled character and simplicity of the original engine. Singer learned this from their turbo program, where extreme power demanded better thermal management.
The manual transmission seems almost nostalgic in 2026.
It's not nostalgia. It's a statement that this car is about engagement, not convenience. A manual forces you to participate in what the engine is doing. That's the whole point.
What does a million-dollar restoration actually mean for the owner?
It means you're not buying a car. You're buying a relationship with a machine that was completely disassembled and rebuilt by people who spent months thinking about every detail. The price reflects that obsession.