MotoGP, Yamaha affair: the valves were different in hardness and geometry

After Yamaha had ended up in the dock over the valve affair, all things considered it got away with very little - a few points less in the constructors’ and teams’ standings, which are completely secondary in MotoGP. The Japanese manufacturer was punished by the FIM for intervening on its engines used in the first Jerez GP to change the valves without having received the permission of the other manufacturers.

Yamaha’s defence was that it had been a simple misunderstanding about the regulation, that there was no desire to obtain any advantage, as the mounted valves were absolutely identical to those deposited with the sample engine, only produced by another supplier.

According to what Speedweek has learned however, this is not entirely true. In fact, the technical director Danny Aldridge sent the two different types of valves to the University of Padua for an opinion from a third party. The tests carried out would have shown a 50% lower hardness for the valves used in Jerez compared to the homologated ones. Which may have been the cause of the numerous breakages in Spain.

But that's not all, because even the design of the valves itself is reported to have been modified, with a difference of 5 degrees found in their geometry.

These data cast doubt on the explanation of the Yamaha management, who spoke only of a different supply, something that suggested a faulty batch, but instead it seems that the component is very different from the deposited version.

These valves were only used at Jerez, then they went back to the homologated component.

It should also be noted that Yamaha was not penalized for using illegal components, but for having violated the protocol that requires the permission of the other manufacturers to intervene on the engines.