Widely considered to be one of the most (if not the most) prolific engines in Formula 1 history, the DFV engine stands as a testament to the fact that simplified designs, weight savings, and high revs can serve as a replacement for displacement.
With 155 Grand Prix wins, 131 pole positions, and a triple crown-winning combo of Monaco, Indy 500, and Le Mans on its resume, there are a lot of accolades that come attached to the DFV engine.
But what made this powerplant so formidable, and for so damn long at that? Hell, the thing was created at a time when CAD software, computer-programmed CNC machines, and digital renderings were little more than science fiction dreams. You know, back when Captain James T. Kirk still had a slim waistline.
Crafted by hand, from sketch sheet to cylinder head, the DFV V8 engine’s backstory is about as brazen and unbelievable as it gets, for it truly is one of the most intriguing underdog stories of the 20th century. A bold claim, yes, but one that is founded upon the fact that the engine was created from scratch in less than a year by a man in his thirties who had never designed a motor from start to finish before.
The gent we speak of is none other than Keith Duckworth of Cosworth. While there were numerous other individuals who helped make the DFV motor a reality, Duckworth was the chief mind behind the build and the proverbial poster child for its success.
After quitting Lotus, and moving over to Cosworth, Duckworth was tapped to help design what would become the Ford/Lotus twin-cam four-cylinder engine. Intended for the funky little Ford Cortina, as well as the downright adorable Lotus Elan sports car, the Cosworth creation hit on all cylinders, and sales took off.
Before long, notions of having a race variant of this peppy powerplant piqued the interest of Ford’s motorsports team. Come the tail-end of 1965, Ford had agreed to fund the equivalent of $280,000 in R&D dollars for a brand new type of Cosworth/Lotus motor program. One with all the revs, and very few hindrances.
But before the record-setting DFV V8 could be engineered, a pint-sized variant had to first be built. Formula 2 was growing in popularity at that point in history, so Ford wanted a smaller, twin-cam 4-cylinder engine to test and affix its badge atop. All told, a total of forty engines were contracted for construction once the prototype had been tested and approved, with every one of these units being up for grabs by any race team that could afford one.
From there, Cosworth was assigned the task of taking the top attributes from the F2 engine that had just been birthed, and concocting a V8 F1 engine from these genetics. Fortunately for Duckworth and the rest of the Cosworth team, they had constructed a really solid foundation to build upon, and much of the twin-cam four-banger’s upper end and overall design language was able to be recycled.
Commonly known as the Cosworth “Four Valve Type-A” (FVA) engine, this high-revving 1,600cc motor utilized four valves and one spark plug per cylinder instead of the standard dual-valve design from that time period. It also came loaded with a dry-sump lubrication system, a series of cup-type cam followers, and a super lightweight spur-gear drive setup to power the lot. These attributes, along with a really slick air induction design allowed the head to flow extremely well and the entire engine to rev like crazy. This resulted in the production of nearly 140 ponies per liter pounding the pavement on a finely tuned F2 race car.
By doubling down on this design, Duckworth and the rest of the Cosworth team believed that it could formulate a V8 engine that could capitalize upon the perks found within the FVA’s head, and drop it all atop a one-off block. A bold, but risky move that would eventually pay off in spades, as it would soon become known the world over as the Ford “Double Four Valve,” or “DFV” for short.
On to Bigger and Better Things
Intended to make its debut during the 1967 race season, Cosworth’s “big” V8 engine was made exclusively available to Team Lotus, with five powerplants in total being built for that year.
Thanks to a recent change in the Formula 1 rulebook, engines were now allowed to have up to 3.0 liters of displacement. They still had to be naturally aspirated, but that was about it when it came to the guidelines at the time. Any kind of cylinder configuration, firing order, and piston count was fair game, which resulted in much of the field running a V12 or larger.
But Duckworth didn’t want to go that big. He knew that with 32 valves pumping away alongside lighter rotational components, and a flat-plane crank on board, the Cosworth DFV could out-compete most of the other engines on the starting grid. Perhaps more importantly, Duckworth knew that the lighter size and smaller footprint of the V8 engine could bring superior perks over larger alternatives. An engineering decision that in time would prove to be one of the wisest ever made in Formula 1 racing.
Outside of the DFV engine’s lightweight, ultra-compact packaging playing to its favor, Cosworth’s creativity and freedom to experiment gave way to all manner of performance gains. A different firing order simplified the exhaust and aided flow to the 90-degree engine, which sucked cold air straight down through the valley between each head. Cosworth had also discovered that by converting the 40-degree angle between the valves on the FVA to 32 degrees, combustion efficiency could be increased, all while streamlining the engine even further.
Despite the valvetrain being able to safely scream all the way up to 11,500 rpm (supposedly), Duckworth and his team felt it best to keep the rev-limit in the 9,000 rpm range. Being that this is Formula 1 racing we are discussing, and there were still quite a few revs to spare upstairs, all peak 400 wheel-horsepower landed right at this redline. According to a January 1967 issue of Road & Track, the gap between the DFV’s 270 lb-ft of maximum torque and peak horsepower was quite narrow, and only occurred once 7,000 rpm was reached.
Meanwhile, back downstairs, the DFV’s one-off aluminum block replaced the clunkier FVA cast-iron design, but retained the rev-rich four-banger’s 85.7 mm bore. However, the DFV needed an “oversquare” bore-stroke ratio to achieve higher revs, so it was shaved down to 64.8 mm. This meant that when fully assembled, the first round of Cosworth’s DFV engines measured only 21.4 inches long, 27 inches wide, and weighed no more than 370 pounds all told.
This tighter and lighter footprint allowed the 2,993 cc V8 engine to accommodate a larger fuel tank, consume less petrol, and capitalize upon a neatly packed dual-port exhaust exit strategy. Coincidentally, it was the DFV’s smaller size and slender dimensions that allowed it such an illustrious (and lengthy) competitive edge in racing. For as with all forms of competitive motorsport, the rulebooks were forever changing, and Cosworth had somehow seen the downforce-filled future of F1.
Bolt-In and Spool Up
Another one of the main reasons why the DFV V8 was such a success for so long, was because the engine itself was load-bearing. By serving as a structural component within the chassis, and allowing the suspension to bolt directly up to the block and gearbox, Cosworth discovered that all manner of now-unneeded components could be eliminated from the equation. This design marked a first for the Formula 1 program and was one that would be copied many times over for decades to come.
Sure, the exterior of the engine had to be reinforced to the point where it could accommodate this additional pressure and any bumps along the way. Yes, it did add a few pounds to the slender V8’s sexy midsection. But even then the design proved fruitful beyond expectation.
By eliminating the rear subframe, the chassis could be lightened all the more, as it no longer needed to support the load of the suspension or be tethered to the constraints of a monocoque structure. Simply affix the engine to the bulkhead and allow it to provide the ballast that was required to meet the F1 homologation minimum weight limits at the time. While exact figures are shrouded in the smoke-filled fog of history, some say that the Lotus team benefited from running cars that weighed anywhere from 200 to 300 pounds lighter than their V12-powered competitors during the DFV’s inaugural F1 race season.
By the 1970s, downforce-oriented ground effects had become mandated by F1, and most V12-powered cars at the time were unable to accommodate these homologations. However the DFV, with its super-slim proportions, had zero issue in allowing venturi airstreams to slip past undeterred. This allowed teams to forego the need to modify their race day setups, and still affix the mandated ground-effects underneath.
And while the DFV engine struggled to make the power that more modern, turbocharged applications were producing in the 1970s and beyond, its impressive display of downforce allowed it to remain extremely competitive. Yet even then, the need for boost gradually began to take precedence, and Cosworth eventually gave in.
The reason for Cosworth’s hesitation had been simple: Duckworth was not a fan of forced induction and thought the DFV motor was perfect the way it was in unmolested naturally aspirated form. But by 1974, he caved, and Cosworth began work on a turbo variant of the DFV: The mighty DFX.
Producing 840 horsepower at 12,000 rpm without any form of boost pressure inhibitor, this first round of DFX engines were absolute rockets right off the line. Being that the engine was intended to be a core rear portion of the chassis itself, and therefore was reinforced to hell and back, it proved to be quite resilient when pushed to these extremes. This resulted in the DFX engine becoming a go-to powerplant for an array of race teams all the way up until the late 1980s, as it dominated IndyCar with ten Indy 500 victories in a row.
Domination by the Decade
But long before the shift to turbo spool occurred, an untested prototype engine and an equally unsure Cosworth team had to be put through the paces. The 1967 Formula 1 race season had arrived, and very little testing had been completed on the DFV motor or the cars that it was powering. Neither the Cosworth team nor the drivers who would be piloting the Lotus-Ford cars on the field that year really knew what to expect outside of a potentially catastrophic learning curve.
But after some pre-race practice, driver Graham Hill proceeded to set a new lap record and then secure the pole position. Meanwhile, teammate Jim Clark had the fastest lap of the race and dominated as the track leader all the way up until the finish line. An astonishingly solid start for an unorthodox engineering feat that had been completed in just a few months by a bunch of young experimentalists.
Naturally, there were some unexpected hiccups along the way with the physical structure of these previously untested engine mounting designs and the DFV engine itself. The flat-plane crank’s rough operation chewed up cam-drive gears and camshafts faster than Garfield in a lasagna factory, and so a hub with quill shafts that could dampen the vibrations had to be implemented. This not only fixed the issue, but it also bumped rev limits all the higher, ultimately allowing the Lotus-Ford team to prevail and dominate the rest of the race season.
Come 1968, Ford had loosened Lotus’ grip on the rev-happy V8, and soon the grid was filled with DFV-powered contenders. From that point until 1982, the Cosworth-engineered DFV engine’s ubiquitous nature helped the engine builder secure 22 Formula 1 titles, as well as a few 24 Hours of Le Mans wins, and the aforementioned decade-long IndyCar dynasty.
All told Cosworth powered 155 victories from 1967 to 1983 with its DFV design, with every single Formula 1 world champion between 1968 and 1974 being propelled by one of these original motors.
But by the early 1980s, the DFV started to show its age, and at the 1983 Detroit Grand Prix, the engine secured its 155th and final Formula 1 win. However, the turbocharged DFX variant would continue to dominate the race track for the next few years, helping secure its place in the annals of history as one of the greatest race engines of all time.