Originally built by Geoff Richardson
Freshly rebuilt by RM Sport
SOLD for £8,333
‘It is a unique combination of racing car and tractor engine and remarkably silent at all speeds.’ Car and Driver on the Lotus Twin Cam engine, 1964
OK, here is something just a little bit off the wall, even for Berlinetta. An ‘all time classic engine’ in anyone’s terms, the Lotus Twin Cam engine was the company’s sole production power plant in a variety of guises throughout the 1960s and well into the 1970s. It nestled in the front and middle of a vast array of road and competition cars from the Elan and Cortina with just over (or was that actually just under?) 100 bhp through to the pure track cars such as the 23B, 26R and 47. Today, it is one of the most popular engines in historic motor sport, from almost standard trim in say HSCC Historic Road Sports form through to highly developed versions in some single seaters or fire breathing rally cars.
This is a documented Twin Cam built originally by race engine ace Geoff Richardson in 1995 – many cars do not have history going back twenty two years, never mind engines! According to the paper trail that accompanies the engine it has a capacity of 1760 cc, but it was never used and was sold on to the sadly recently deceased previous owner. During their tenure the engine was rebuilt by RM Sport and tested on race engine specialists Mass’ dynamometer where it gave an impressive 183.4 bhp at 7,500 rpm with 139.4 lb ft of torque at 6,000 rpm and excellent power from 3,000 right through to 8,000 rpm. It is otherwise unused since this rebuild.
Geoff Richardson originally built this ‘all steel’ engine using an early ‘D’ type Lotus Twin Cam cylinder head, suitably modified by himself. He based the bottom end of the engine on the remarkably robust Ford ‘711M’ block which is renowned for withstanding big power outputs and high engine revolutions even with its standard main bearing caps.
Believed to be in much the same specification now, the engine is currently fitted with an Allen steel crankshaft complete with twelve bolt steel flywheel, Farndon rods and Cosworth pistons. Twin 48 DCOE Weber carburettors with twin throttle linkages and aeroquip hoses feed the engine via QED valve train while lubrication is taken care of by a Titan dry sump system. A machined cam cover (with no oil filler obviously) is fitted along with an alternator driven by a wide grooved belt.
As mentioned above, RM Sport have recently rebuilt the engine with new gaskets, springs, bearing and seals along with new bolts as required and photographs of this are included in the file and can be seen in the photo gallery. Also in the file are letters and notes regarding the specification of the engine and its provenance plus the all-important Mass dyno sheet.
Today this engine would cost in the region of £20,000 to build but suffice it to say, it is reserved at what we feel is a very realistic figure somewhat less than half that. While its ‘711M’ block may make it unsuitable for use in certain branches of Historic Motorsport, less ‘precious’ classes would welcome it with open arms.