Jim,
Having spoken with Klaus in the garage after the race, I may have misstated the situation slightly. It was a flywheel that flew apart. It turned out to be a standard Fiat flywheel that had been lightened by machining away some of the mass. As these flywheels are cast, there is a reason why they are designed with a particular thickness, namely for strength.
Yes on the downshift from 5th to 4th at the chicane on the back straight it did come apart. Apparently the change in enertia was simply too much for it. Large chunks of metal could be seen coming out from under the car. Apparently it destroyed the flywheel, clutch, pressure plate, transmission imput shaft, crankshaft, block, bellhousing, and at least one rim and tire. Not to mention the shrapnel holes in the chassis. Thank heavens that it was behind the driver !! Apparently the head looked OK.
The irony was that Klaus actually had one of my aluminum flywheels that he had purchased some time before, but he had not gotton around to installing it.
BTW - His son rebuilt the motor and gearbox for the next race and at that race he dropped an exhaust valve. Maybe the head was not OK, but we will never know.
So much for the autopsy.
