True! I had several cylinder hold down studs to break off during flight.
Engine ran fine the whole trip. But the tip off came when an oil streak
was noted on the side of the engine cowling, and when looking for a
leak, the 1st of several broken studs was found in the bottom of the
cowling. Further investigation disclosed several broken studs - all
traced back to inadequate torque. When checked, the remaining studs
didn't have the right torque.

It will happen with improper torque values. The engineers didn't
establish them just for fun.

John

On 8/27/2012 8:50 PM, David Beierl wrote:
> The most usual cause of otherwise correct bolts breaking is
> insufficient torque when installing.