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The Rover-BRM was a prototype gas turbine-powered racing car, jointly
developed in the early 1960s by the British companies Rover and British
Racing Motors (BRM).
Rover had already been working with gas turbines for road vehicles since
World War II. A series of potential road cars had also been produced,
from the early prototype Jet 1 through the more developed examples T2,
T3 & T4. T4 had even displayed demonstration laps around the Le Mans
circuit, before the 1962 race. Seeing an opportunity for even more
prestige, Rover decided to enter a gas turbine car into the race. A
prize was to be awarded for the first gas turbine car to complete 3,600
km over the 24 hours, an average speed of 93 mph.
A crucial step in this plan was a chance meeting between William
Martin-Hurst, MD of Rover, and Sir Alfred Owen of Rover's component
supplier Rubery Owen, but more relevantly also of the Formula 1
constructors BRM. BRM supplied the chassis of Richie Ginther's
crash-damaged car from the 1962 Monaco Grand Prix. A custom open-top
spyder body was then built in aluminium, with the turbine mid-mounted
ahead of a single-speed transaxle.
The first test runs were at the MIRA track in April 1963, driven by
Graham Hill who described it thus, "You’re sitting in this thing that
you might call a motor car and the next minute it sounds as if you’ve
got a 707 just behind you, about to suck you up and devour you like an
enormous monster." The top speed is quoted to be 142 mph (229 km/h)
1963 Le Mans
The car ran at Le Mans, carrying the race number "00" as an
experimental car. The turbine engine was judged to be equivalent to a
2-litre, but was permitted twice the usual fuel allowance. Le Mans has
always taken an interest in fuel efficiency and some classes depend on
achieving particular figures. Graham Hill and Richie Ginther, who had
past experience of the same chassis in a different guise the year
before, drove in the race.
The 3,600 km figure was achieved with hours to spare, and with
peak speeds down the Mulsanne Straight exceeding 140 mph. The overall
averages were of 107.8 mph and 6.97 mpg. As the only car in its class it
was unplaced, but the same performance by a petrol-engined car would
have placed it in 8th place.
1964 Le Mans
For the 1964 season, the major change was the addition of a pair
of ceramic rotary regenerators to the gas turbine, so as to improve
efficiency. Although often reported as "heat exchangers", these use a
different technique. Two honeycomb disks rotate slowly at 20 rpm with
both inlet and exhaust airflows passing through them, but separately.
This heats the disk, which then rotates, and in turn heats the inlet
air. Regenerators slightly restrict the peak power of a gas turbine, but
hugely increase its efficiency in compensation. The car also gained a
new body, a closed coupe designed by Rover's William Towns. To improve
intake airflow, large pods were added over the rear intakes, after the
test weekend, where it ran with small air scoops. There was little time
to test the new engine however, and the car was also slightly damaged
during transport back to Britain. For one of these reasons (history is
unclear just which), the team withdrew from Le Mans that year.
1965 Le Mans
The 1964 engine was now used to race in anger. Rather than
running as an "experimental", it was numbered "31" and was a competitor
against others in the 2-litre class. The fuel allowance was also now the
same as for the piston cars, making the regenerators even more
important. Graham Hill and Jackie Stewart were to drive.
Allegedly owing to sand from the side of the course being sucked
in when Graham Hill ran wide early on, the turbine blades were damaged.
The engine began to overheat and for the rest of the race had to be
monitored carefully to ensure that the exhaust gas temperature wasn't
exceeded. Some hours later, while Stewart was driving, the tip of a
turbine blade broke off and damaged one of the regenerators with a
massive explosion, although the engine kept on running.
The car performed well though, finishing tenth overall, seventh
in the prototype class, and the first British car. The average speed was
slightly lower than previously at 98.8 mph but consumption had fallen in
half to 13.51 mpg. |
