was just flying along normally and the rod just bent/broke for
no reason!" -- Not Quite
First cause - Hydraulic
Lock - This happens when there is liquid fuel in the cylinder
and an electric starter is applied to the engine. Liquid will
not compress like a fuel and air mixture so the only thing
that can happen is the rod will bend as the piston is stopped
prematurely at the top of the stroke.
The engine will
then become stiff as the piston is not aligned with the cylinder
bore. The engine could start at this point and you would not
realize you bent the rod. You may also just bend the rod slightly
and not even notice.
If the engine does
start with a bent rod you may be able to run it for awhile
but eventually it will either seize or the rod will break.
Many times the engine will quit midair so you think "I
was just flying normally and the engine stopped!".
The bent rod causes
two things --
of the rod on the crankpin so the rod is pressing against
the rear cover. This rubbing causes friction thus heating
the rod and allowing the lower bushing to spin. Next the rod
breaks. See HOW
TO FIX A BROKEN ROD
of the piston in the cylinder bore causing lack of clearance
on the top and bottom of the piston on opposite sides. Hence
more friction and eventually galling or seizure.See SCORED