Way before Audi entered endurance racing and dominated the 24 Hours of Le Mans for a decade, it was Porsche that ruled the most grueling motor race on earth. In fact, Porsche still remains the winningest constructor in Le Mans history. 

Porsche returns to the premier class of endurance racing and revealed its Porsche 919 Hybrid LMP1 race car in December. Now, Porsche has finally revealed the details of its power unit as well-- a radical gasoline-powered V4 engine with a single turbocharger sitting between the banks was designed specifically to package itself with a hybrid system. If there were ever a time to use the term "game-changer," this is the time.

There's a very good reason why even a very knowledgeable car enthusiast will have trouble naming all the cars featured a V4 engine. A "Vee" formation 4-cylinder engine is one of the least popular layouts in automotive engineering due to it's inherently unbalanced design. In fact, a V4 has never been applied in any premier racing series (at least not with any level of success).

However, Porsche believes it has developed a perfect V4 powerplant that is uniquely suited for Le Mans endurance racing. According to Autocar, Porsche is rumored to have adopted a powered V4 engine with an extremely wide, near-180 degrees, "Vee" formation. The design not only makes the V4 engine run smoother, but also achieves the compact dimensions neccessary to position the Porsche 919 LMP1's battery and hybrid drive system in a way that will not affect the weight distribution or center of gravity of the race car.

The V4 design has its own inherent benefits as well. Porsche's V4 engine will be stiffer due to its short block. Torque is also plentiful from the turbocharged 16-valve 2.0 liter direct-injection 4-cylinder engine. Finally, lower cylinder count will reduces weight and improve fuel efficiency. The Porsche 919 Hybrid LMP1's V4 will run on gasoline engine, unlike the diesel powered Audi R18 e-tron Quattro. In addition, Porsche's turbo system will not be electric, which marks another notable distinctionn from the system in the Audi.

The turbo V4 engine is responsible for driving the rear wheels only, while an electric system drives the front. Two energy recuperation systems, KERS and ERS, are installed on the car. The KERS system harvests kenetic energy from the brakes while the ERS harvests energy from the turbochargers. The batteries on board are lithium-ion units suppled by U.S.-based A123 Systems.

Even though the Porsche 919 Hybrid LMP1 race car will be competing the entire 2014 World Endurance Championship (WEC) schedule, particularly heavy emphasis is obviously being placed on the Le Mans 24 hours. Porsche's drivers will include former F1 driver Mark Webber, former Lola/Rebellion LMP1 driver Neel Jani, and former Le Mans winners Timo Bernhard and Romain Dumas. 

The Porsche 919 Hybrid LMP1 will conduct further testing in mid-February at Bahrain before the inaugural race will take place at the Silverstone Six Hours on April 20. The 2014 WEC series also includes Spa, Le Mans, Interlagos, the Circuit of the Americas in Texas, Fuji in Japan, Shanghai and Bahrain.

Watch the videos below to learn more about Porsche's incredible 919 race car: