Subaru Impreza 10000 RPM engine

Takhle vypada subaru motor kteremu upadne ventil v 10000 otackach. - This is Subaru engine, broken valve in 10000 RPM. This was not poorly tuned, EGT and AFR was right, Problem was in material of one of the Cosworth valves, there was air bubble in it and it broke apart. This was not one shot as you think, this car was running few months before this and it is running again fine after repair. But we changed manufacturer of vents :-)