|THE MINI MAG. Volume 2 No.9|
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THE INCREDIBLE 8 CYLINDER MINIS.TWIN-ENGINED Minis are erupting into the British racing scene. BMC is already preparing a production version of the Jeep style utility, the Mini Moke, which was successfully demonstrated in deep snow last winter, and with both Cooper and BMC involved in construction of experimental twin-engined sedans, a production twin-engine four wheel drive sedan seems a distinct possibility.
Twin-engined Morris Minis, with a top speed of 135mph and better acceleration
than a Jaguar E-type, are just around the corner.
Using two normal Mini Cooper engines, a power to weight ratio of nearly 160bhp per ton could be achieved, which would give sensational performance at modest cost. But Cooper has built a prototype which has about 256bhp per ton, which should drivers of Ferrari Berlinettas something to think about.
First to try out the twin Mini idea was designer and racing driver Paul Emery, who used two normal 848cc front drive units, tuned with twin carburettors and special exhaust systems. The rear power unit, with its transmission and suspension, goes where rear seat and trunk used to be. Its special cross member is bolted in and there is an additional tube across the tops of the suspension attachments. Both clutched are controlled hydraulically by one pedal and both engines are linked to one gas pedal.
Control of the rear gearbox is complicated by the fact that the stub lever emerges from the crankcase on the extreme rear. Emery solves this by using an aircraft type flexible control linked to the existing central lever.
For this season’s racing, Emery plans to re-equip the car with two Mini Cooper units which he believes will give it acceleration better than an E-type Jaguar. But he regards this as only the first step. On his drawing board there is a streamlined two seater twin engined coupe with glass fibre body which he hopes will do nearly 150mph, with acceleration to match almost any current sports car, regardless of cost. He believes this can be produced in quantity for not more than 2,250 pounds.
Cooper has built the most potent twin so far. The front engine of 1098cc develops 83bhp and the rear unit of 1220cc contributes another 96 making a total of 179bhp for a weight of 1580lbs. This car has disc brakes on all wheels and special Cooper cast magnesium wheels carrying 5.20 by 10inch tyres on wide base rims.
Duplicated instrumentation is necessary for multiple engined Minis. Note the new position for the handbrake.
With final drive ratios of 3.5 instead of 3.7 to 1, maximum speed is expected to be about 135mph. Cooper has modified the rear gear shift mechanism so that it can be operated by a jointed tube from a big central lever which is also linked to the front gear shift. The boot lid is perforated and fixed open a few inches to circulate air to the rear radiator.
Meanwhile, BMC has built its own prototype with two 997cc Mini Cooper engines. It is the most refined designed so far, with the rear engine enclosed in a sound proof casing. Both gear shifts are linked to one big central lever. There is a grille in the left rear body panel as an outlet for air from the rear radiator, and there are wire mesh grilles in the trunk lid. Two engines reduce high performance Minis to strict two seaters. This BMC made vehicle has fully civilized sound proofed interior. BMC is expected to run one in the Targa Florio and production run of 100 to obtain homologation in the 2 litre GT class seems a distinct possibility. Both BMC and Cooper twins have extended instrument panels with instruments for front and rear engines.
These twin Minis naturally have terrific acceleration. Controls are heavier to handle, but not excessively so. With all weight concentrated within a short wheelbase, they retain instant steering response, coupled with a ride which is fairly hard, but well damped by the extra weight. Coupling both gearboxes to one lever makes it fairly easy to disconnect one engine and put its gearbox in neutral in the event of mechanical trouble.
The twin engined Mini Moke which BMC is now preparing for production will probably have bigger wheels and higher ground clearance than the prototype. But credit must go to Citroen for being first in the field by a couple of years with a twin engined car, the Sahara version of the 2 CV. Devised originally for the oil men prospecting in the Sahara, who wanted a light four wheel drive go anywhere vehicle, it has found many other buyers who have to contend with sand, snow or deep mud.