The advance of anti-pollution regulations brought with it the general end of large engines, to the great dismay of many enthusiasts. But Yamaha wants to find a chance for its survival. On the occasion of the last round of the Super Taikyu championship in Okayama, the tuning fork brand presented a prototype of a V8 powered directly by hydrogen instead of gasoline, and which only emits water. 'exhaust.
A video from the YouTube channel LoveCarsTV! reveals the look and some of the specifications of this block. It is based on the Toyota 2UR that Lexus uses in the RC-F coupe, has a displacement of five liters and can deliver up to 442 horsepower at 6 rpm, and is conveniently modified to suit the characteristics operation of hydrogen combustion.
The most obvious changes in this aspect are new injectors, fuel lines or valve seats. However, the modification that truly differentiates it from the gasoline V8 concerns the meticulous work carried out on the exhaust manifolds. These have the same length for all the conduits that come out of the two cylinder heads, which means that the expelled water travels the same distance from each of the cylinders and with the same speed. In this way, it manages to extract the maximum possible power.
This acoustic configuration linked to the length of the exhaust also manages to improve the torque at low revs, as well as the response speed of the engine at low revs. In addition, this engine can operate with a lean mixture – that is to say with a low level of fuel compared to that of the air – thanks to the high volatility of hydrogen, an advantage which allows obtain an almost flat torque curve, this being constant in the range of 500 Newton meters from 2 to almost 000 rpm!
Yamaha, for its part, is no stranger to the development of engines for vehicles although it is a brand more dedicated to two-wheelers. Unsurprisingly, the in-tune brand was responsible for developing the mechanics of the Toyota 2000 GT from 1967, considered the first Japanese supercar and now sold at an exorbitant price. Without going that far, they were also responsible for refining the magnificent V10 engine of the Lexus LFA, which could however make its return both in electric format and with the aforementioned V8 engine in development.
This engine is a continuation of the agreement that Yamaha signed with Toyota, Mazda, Subaru and Kawasaki to promote competition using alternative energies. Therefore, it would not be strange to find it in the future in a prototype of the Japanese Super GT championship or even under the hood of a hypercar.
But to do this they must first find a way to overcome the current disadvantages of this type of engine, such as the bulky storage of hydrogen or the lower efficiency of this combustion compared to the fuel cell.
