Mahindra is India’s 21st-largest corporation, manufacturing cars, trucks and the tractors that are being exported to (and built in) the U.S. For the leadership of such large corporations, having something international, like Tata Motors’ ownership of Jaguar/Land Rover, confers satisfying special prestige. For Mahindra, that prestige is its Moto3 team, which, at the first Grand Prix of the season at the Losail Circuit in Qatar, finished seventh in the hands of rider Miguel Olveira, ahead of all the Honda-powered entries. At Circuit of The Americas, 18-year-old Olveira was fifth, very much among the series-leading KTMs.
Moto3 replaced the FIM’s 125cc GP class, which ran from 1949 to 2011. Moto3 attempts to limit the runaway costs of uncontrolled development by creating a viable “farm league” through which future champions can enter international racing. Each engine is limited to a single 250cc cylinder of maximum 81mm bore, with four valves driven in unvarying timing and lift by a cam or cams set in motion by a single chain. Revs are limited to a maximum of 14,000, and a spec ECU is required. Engine price cannot exceed 12,000 euros and a life of 2000 kilometers (1240 miles) must be guaranteed. With such limits, a likely maximum power is 50 to 55 horsepower, the same output as the previously used 125cc two-strokes.
I had an opportunity at CoTA to speak with Mahindra crew chief Emanuele Martinelli. He told me that the new Mahindra 250, whose design was contracted from Suter Racing Technology in Switzerland, was originally expected to deliver in the range of 46 hp but actually gave “much more,” which we see in its first results. Of greatest importance in such a limited class is friction reduction.
“In the Honda [Moto3 engine],” said Martinelli, “the cam chain wraps tightly around a small sprocket on the crankshaft. Because of this, the ‘polygonizing’ of the chain is extreme [that is, it must bend sharply as its pins and links pivot into the tooth spaces of the crank sprocket]. This generates extra friction.”
In the Suter/Mahindra engine, a pair of gears drives the lower cam sprocket, reducing its speed and allowing use of a larger, less-tightly wrapped chain sprocket. This is the same gear-and-chain drive concept used on the classic British AJS 7R and G-50 Singles of the 1950s. Look in any handbook from a chain manufacturer and you will see that the minimum recommended number of sprocket teeth for longest life and lowest friction is 20. Now, count the teeth on the chain sprocket on any streetbike’s crankshaft—not very many!
Martinelli also noted the value in lap time of tuning an engine not for peak power but for torque that is smooth and wide enough to cover the ratio spreads in the six-speed gearbox (only two alternative ratios are permitted for each, rather than the five that have been typical in the past). In this way, the rider can always count on acceleration and will not be “left hanging” in a corner at 10,400 rpm by an engine whose torque begins at 10,600.
Honda’s Moto3 engineer Hideki Iwano commented last year that to make such racing affordable by many teams, its technology must be of a new kind: good and also cheap. It is encouraging to see Mahindra at a competitive level. Up to now, it has been a two-tier affair: KTM Cup for the roughly top-10 positions and Honda Cup for the rest. Mr. Iwano also noted that even though this is a beginning class, Honda still wants to win. What’s next?