[Henry Schmidt]

About four years ago, I had the occasion to disassemble a 3.5 turbo engine from a PCA race car.
The car was racing when it suddenly started to smoke.
The car was driven into the pits and parked.
At that time I had the pleasure of trying to ascertain the problem.
The smoking was caused by a magic window in the top of the case.
Upon inspection we discovered that the connecting rod had broken in the middle about 1 1/2 inches from the small end.
The rod bolts were in tact and the crank was inspected for cracks and straightness then reused.
The piston was entirely in tact. No valve was even bent.
There was damage to the case and the base of the cylinder.
The rod was sent to Critical Operations for analyses and the conclusion was a crack from a stress riser as the result of a casting flaw.
One thing you'll know if you do enough engines is that you haven't seen it all. Now, when we build race engines with used rods is that magna flux for cracks is required.
This flaw in a normally aspirated engine or even a turbo used on the street may have lasted the life of the engine.