The Long Read: Lotus and the “25” – Part 3

Part 3: Lotus in 1962 – Chassis Revolutions,
Five New Cars and a New Engine

As mentioned in Part 1 and Part 2 of The Long Read, the Lotus collective of bright and talented engineers and aircraft industry trained draftsmen (Chapman, Mike Costin, Len Terry etc) had overlooked the first chassis revolution of mid-engined F1 cars set off by Cooper. It taught Lotus a huge lesson and in 1960 the first mid-engine Lotuses appeared (type 18 and 20). Carlo Chiti at Ferrari needed an extra year. Despite his ties to Lotus, Mike Costin did not try to hide his admiration for Cooper in his book:

“Coopers themselves do all they can to perpetrate the old fable about chalk on the wall and piles of tube on the floor, but there is a good reason for every design feature of their cars, and this is just one instance.”

The Monza accident was the biggest accident in 70 years of F1 GP history (to the present day). A month later, in October 1961, US racers filled up the grid of the non-championship US GP at Watkins Glen, but without Ferrari (out of respect) and without Clark. Innes Ireland won the race for Team Lotus, (its first outright GP victory by the team – as Moss had already bagged the first Lotus GP win at Monaco).

It truly highlighted all the dangers of motorsport as it was a racing accident which could have involved any car on the grid. More spectators could have been killed if they had been more tightly massed. Clark was unhurt but not cleared of blame for two years. Despite this accident – which followed previous shockers at Le Mans in 1955 and not least at the Mille Miglia in 1957 – improving safety was still secondary to speed on the design agenda.

1962’s pipeline clearly started in 1960. Although Lotus was used to high speed innovating, had many motivated and talented brains and a new factory in Cheshunt, cars always take time to develop. Yet, the level of “work in progress” was highly surprising for such a small company: The catalogue included 5 new cars including a Formula Junior, a sports prototype for Le Mans, two Grand Prix cars (!) and the new road going sportscar, the Elan, powered by a new Lotus engine. In addition, the Lotus 7 and Elite were also still in production!

I will cover the second chassis revolution in Part 4 on the Lotus 25. Simply put, instead of having a single torsion box “spine” of the new two-seater road car (the Elan), the Lotus 25 placed the driver between twin torsion boxes. This – in all its simplicity – was the very invention of the “racing tub” as utilised by all modern single seaters.

So what were the revelations of 1962?

The Lotus 22 Formula Junior was an updated 20, thereby combining Grand Prix suspension and spaceframe chassis expertise with 4-wheel disc brakes, the dry sump Ford 105E (MkIV) Cosworth prepared engine of 1098cc and 100 bhp (in period) matched to either VW Beetle or Renault Dauphine transmissions.

FJ’s had to comply to certain chassis dimensions, a minimum weight of 400kg and had to use an engine of less than 1100cc from a recognised production car (exceeding 1,000 built per year). Most interestingly, the brakes had to come from the same model that supplied the engine, but a different production transmission could be used.

Truth be told, the only junior items were the engine size and thereby also the brakes. In February 1962, John Bolster reported in Autosport from a Goodwood test “The (recumbent) driving position was new to me but I got up to 120 mph on my first lap…the cornering power is phenomenally high…the better the car holds the road, the more difficult it is to exploit it fully, and the very best drivers will be able to give the Twenty-Two everything they’ve got.”

By the end of 1962, out of a worldwide total of 38 races, all of 24 were won by a Lotus 22 (and 11 of these by Peter Arundell). But it wasn’t through lack of competition. Cooper were supported by Ford’s rival, BMC, and the works team was indeed run by Ken Tyrell and featured both current and future F1 race winners such as Hulme.

The Lotus 23 was a small capacity sports prototype that was aimed at Le Mans. This was essentially a widened 22 designed by Mike Costin. When Jim Clark debuted the 23 with one of the first Lotus Ford 1.5-litre twincam engines (now termed a 23B) at the Nürburgring, the car was so devastatingly fast it set off alarm bells with all other competitors for Le Mans. Before being struck by an exhaust gremlin, the little 23 had pulled out a 2-minute lead in only 8 laps (about 175 km) over the works Aston Martins, Ferraris, and Jaguars.

In turn, this led to the scrutineers being pedantic at the Le Mans 24-hour race where it was presented with a Cosworth FJ 105/107E 997cc engine for the 1-litre class and a Coventry Climax FWMC 742cc for the under 750cc class; both classes traditionally favoured by French entrants.

The most valid reason for scrutineering refusal – the 4-stud spare wheel could not be mounted on the rear 6 stud hub – was solved by Lotus machining a 4 stud rear hub overnight and flying it to Le Mans with the engineer to prove the stresses (Costin). However, the “4-stud” 23B was still not authorised by the ACO but later won the Clermont Ferrand 6H and the Montlhery 1000km in the hands of Bernard Consten. Even so, the Elite managed to win the 1300cc class and Lotus subsequently no longer entered the race.

In current historic racing, Lotus 23s no longer face Ferraris (250GT/330/246SP/268SP) or Porsche 904s which have largely become garden party exhibits. Instead, it competes against 500 bhp “continuation” Ford V8s, or 400bhp Aston Martins and Jaguar E-types!

Significantly, Lotus’ first engine and perhaps one of the most legendary engines to come out of the 60s, the Lotus Ford twincam, was being prepared for production with an advanced Ford block and was intended not just for the 23B, but for the 26 (the Elan) and 28 (the Cortina). This was a collective effort involving Ford, Harry Mundy (designer of the XK engine and Coventry Climax products), Richard Ansdale, Keith Duckworth and Lotus production engineer, Steve Sanville.

Then there was the Lotus 24 – a new space framed Grand Prix car built to start the 1962 season. The chassis was made by subcontractors Arch Motors (who are the manufacturers of the Caterham (Lotus 7) chassis).

Visually, like the 21, the 24 benefitted from Cooper’s 1961 unsuccessful shakedown of the Coventry Climax FWMV V8 engine. The GP car was aimed at both customers as well as Team Lotus (12 cars were produced).

The 24 already brought with it a long list of new, untried developments:

• The new FWMV8 engine was “next generation of engines that would easily attain five-figure rpm speeds. Its broad power band and no appreciable lowering of brake thermal efficiency meant it enhanced the drivability of a good chassis” (Tipler).
• The untried Lucas fuel injection and transistorised ignition
• The new ZF 5-speed transmission.
• The new front suspension of the 21 (1961) was to be updated with new cast uprights.
• The Dunlop tyres were changing with every season. This had impacts on chassis design.
• The driving position was more reclined than the 21.

Having carefully considered the timeline in conjunction with the research made by John Tipler, we can see that the 24 was a stop-gap car whilst the radical 25 was being prepared. Especially as Lotus had not given any of the above developments a proper shake down prior to commencing racing. The FWMV8 was an evolution that effectively leapfrogged Ferrari’s engine technology whereas the chassis of the 24 was objectively comparable to that of BRM.

The car shown below was available at Paul Matty Lotus (pictures also courtesy of Paul Matty) at the time of writing. It is fitted with the BRM V8 used by many customers from mid-1962 onwards.

The 24 was in a sense the vital “test mule” for all these innovations bar the chassis.

Now, finally getting to the Lotus 25, it was the first F1 car with an identifiable “tub”. It speaks volumes of the self-confidence within Team Lotus that the 25 was unveiled without testing in May 1962 at Zandvoort, practising for the first championship event of the season. For the upset and surprised customers of the Lotus 24, it was described by Colin Chapman as the “63” car! We will analyse this in much more detail later on.

The final project of 1962 was the Lotus 26 – the Lotus Elan. Designed by Ron Hickman and using the new Lotus Ford twincam engine mentioned above it was intended as a road car.

Indeed, the new car cost just £27,000 in total to develop: this was the equivalent of three new Bentleys at the time…

But no matter the humble development costs, the Elan still became the very basis of Lotus’ manufacturing from 1962 to 1973. The torsion box chassis was extended firstly for the mid-engined Europa and then for the Elan +2.

Once again, make sure to tune in next week as we dig deeper still…