Öncelikle şu 1.300cc konusuna bi açıklık getireyim. Bir de Le-mans konusuna da değineyim. İkisi direk bağlantılı aslında.
Normal bir motorun 2.600cc hacmi, Wankel motorun 1.300cc'sine tekavül eder. Normal motorda motor şaftı 1 devir yapınca sadece 2 silindirde yanma gerçekleşir yani 2.600cc'lik bir motorun 1.300cc'lik hacminde yanma gerçekleşir.
Wankel'de ise motor şaftının 1 tur devrinde bütün silindirlerde yanma gerçekleşiyo. Yani 1.300cc'lik bölümde yanma oluyo.
Le-mans'ta bir süre sonra yer alamamasının sebebi de bu hacim kısıtlaması. 1.300cc'lik Wankel'ler ancak 2.600cc'lik normal motorlarla yarışabilir. Böyle bi durumda da Wankel'ler nal toplar zaten.
There are various methods of calculating the engine displacement of a Wankel. The Japanese regulations for calculating displacements for engine ratings use the volume displacement of one rotor face only, and the auto industry commonly accepts this method as the standard for calculating the displacement of a rotary. However, when compared on the basis of specific output, the convention results in large imbalances in favor of the Wankel motor.
For comparison purposes between a Wankel Rotary engine and a piston engine, displacement and corresponding power output can more accurately be compared on the basis of displacement per revolution of the eccentric shaft. A calculation of this form dictates that a two rotor Wankel displacing 654 cc per face will have a displacement of 1.3 liters per every rotation of the eccentric shaft (only two total faces, one face per rotor going through a full power stroke) and 2.6 liters after two revolutions (four total faces, two faces per rotor going through a full power stroke). The results are directly comparable to a 2.6-liter piston engine with an even number of cylinders in a conventional firing order, which will likewise displace 1.3 liters through its power stroke after one revolution of the crankshaft, and 2.6 liters through its power strokes after two revolutions of the crankshaft. A Wankel Rotary engine is still a 4-stroke engine and pumping losses from non-power strokes still apply, but the absence of throttling valves and a 50% longer stroke duration result in a significantly lower pumping loss compared against a four-stroke reciprocating piston engine. Measuring a Wankel rotary engine in this way more accurately explains its specific output, as the volume of its air fuel mixture put through a complete power stroke per revolution is directly responsible for torque and thus power produced.
The Sigma MC74 powered by a Mazda 12A engine was the first engine and only team from outside Western Europe or the United States to finish the entire 24 hours of the 24 Hours of Le Mans race, in 1974. Mazda is the only team from outside Western Europe or the United States to have won Le Mans outright and the only non-piston engine ever to win Le Mans, which the company accomplished in 1991 with their four-rotor 787B (2,622 cc/160 cu in—actual displacement, rated by FIA formula at 4,708 cc/287 cu in). The following year, a planned rule change at Le Mans made the Mazda 787B ineligible to race anymore due to weight advantages. Mazda is also the most reliable finisher at Le Mans (with the exception of Honda, who has entered only three cars in only one year), with 67% of entries finishing.