The Lotus 49 consolidated the principle of using the motor that as an integral structural component of the design that was first seen on the BRM P83 and Lotus 43 which were both powered by the novel BRM H16 motor in 1966. The 49, designed by Maurice Phillipe however was powered by the then brand new, and much simpler Ford sponsored 3 litre / 183 cui 8 cylinder Cosworth DFV that was the brainchild of Keith Duckworth and Mike Costin.

Despite many faults that would surface and be ironed out over the ensuing seasons the Lotus 49’s made a dream debut at Zandvoort for the 1967 Dutch Grand Prix with Graham Hill qualifying on pole and Jim Clark who had never so much as sat in the car before the first practice qualifying 8th. During the race Clark driving chassis #R2, seen above with Jackie Oliver at the wheel at Goodwood, used his legendary speed and mechanical sympathy to well judged victory while Hill experienced timing gear failure with two teeth next to each other on the timing gear breaking. After the race it was discovered Clark’s car had experienced a similar failure however a single tooth remained between the two broken teeth on Clarks timing gear ensuring just enough drive to make it to the finish.

Clark used Chassis #R2 to win both the 1967 British and US Grand Prix before being converted to 49T spec for the Tasman Series of races in Australasia which required an engine capacity of 2.5 litres / 152.5 cui which was achieved by fitting a different crankshaft with a shorter stroke to the DFV motors making them DFW spec. Jim won 4 races in the 8 race Series with the 49T spec chassis #R2 which combined with a couple of points paying places was enough to win the Championship from Chris Amon in his Ferrari 246 Dino.

Chassis #R2 was then loaned to Rob Walker racing during 1968 to replace chassis #R4 which driver Jo Siffert had crashed on his debut in a non championship race at Brands Hatch. Although #R4 was not damaged beyond repair by that accident it was subsequently destroyed in a workshop fire at Rob Walkers premises necessitating the loan of #R2. Once Walkers team had built up a new car, chassis #R7 now in B spec with the tall rear wing, which Siffert used to win the 1968 British GP.

Once chassis #R2 was returned by Rob Walker to Lotus it was immediately pressed into service again after Jackie Oliver had a comprehensive accident in #R6 at the 1968 French GP. For the British Grand Prix #R2 was repainted in Gold Leaf Team Lotus colours and fitted with the winged 49B spec nose cone and high rear wing. The car received further B spec upgrades for the German Grand Prix. Oliver would use chassis #R2 for the remainder of the 1968 season scoring a best 3rd place finish at the season finale in Mexico.

The car seen above at Beaulieu National Motor Museum is chassis #R3 which featured subtle differences to chassis #R1 and #R2 to aid the distribution of loads under braking at the front and to aid access to the brake balance adjuster which had previously only been possible by two mechanics picking up a third smaller mechanic and lowering him into the cockpit upside down ! Note the sculpture of Graham Hill on the plinth to the left of the car in this photo.

Chassis #R3 first appeared at the 1967 British Grand Prix with Graham Hill at the wheel, he qualified 2nd behind Clark but while leading the race first an allen screw dropped off the rear suspension and after it was replaced the engine failed while he was making up good time. Chassis #R3 has the second longest track record of the 12 Lotus 49’s built.

After Hill scored a season best 2nd place in the 1967 US Grand Prix, behind Clark, and opened his championship winning 1968 season with another second place, again behind Clark at Kyalami chassis #R3 was sold to Rhodesian John Love who used the car to win the last two of six consecutive South African Formula One titles in 1968 and 1969, his successor Dave Carlton won the 1970 South African Championship driving the Lotus 49 chassis #R8 which was built to the final C spec.

The 400 hp Ford Cosworth DFV was to become the mainstay of Formula One right through the 1970’s, it was far in advance of the Lotus 49 chassis and would only be toppled by the hugely more expensive turbocharged motors in the early 1980’s after 155 Grand Prix Victories. One of the triangular aluminium top engine mountings can be seen bolted with three bolts on the leading edge of the cam cover tapering into the back of the monocoque to which it was attached by a single bolt. Three further such mountings were all that were required to integrate the motor into the structure of the car.

The rear suspension and drive shafts and gearbox would repeatedly prove trouble some for team Lotus as they got to grips with having such a powerful motor. The ZF gearbox in it’s original form was not strong enough and required additional strengthening which can be seen in the form of the thick vertical plate into which the drive shaft disappears. The ZF gearboxes were replaced on the 1968 B spec cars with Hewland units which were much easier to maintain trackside.

The vestigal nudge bar was added to the back of the ZF gearboxes after the 1967 Dutch Grand Prix win in order to comply with a regulation about the dimensions between the end of the exhaust pipe and the back of the car. In other words when Jim Clark won the 1967 Dutch Grand Prix his Lotus 49 did not comply fully to the letter of the existing regulations.

Chassis #R3 is the only one of the Lotus 49’s never to run in B or C spec. Since it has been in the care of the National Motor Museum it has been involved in two serious accidents. The first, on a demonstration run, involved a tree in the Beaulieu grounds where it is kept in 1999 further details of the accident damage can be seen on this link. The second accident with the same driver occurred at a Silverstone Press Day in 2009 fortunately the damage was restricted ‘only’ to the left side suspension as can be seen in these linked photo’s.

Thanks for joining me on this “What Is In A Tooth ?” edition of “Gettin’ a li’l psycho on tyres”, I hope you will join me again tomorrow when I will be looking at a GSM Delta. Don’t forget to come back now !