Bayou Bert
Well Known Member
I guess it has been so long the thread I started with the same name
is gone.
Time for update and conclusion.
Below is graph of RPM of take off this morning, from start of roll to 1000'.
This is after changing crankshaft to one with the tube across the inside
with a slot cut in the center of the tube.
Below is graph of RPM of take off from start of roll for 30 seconds with the old crankshaft with only
a hole in crankshaft wall, no tube.
As you can see, no sag, no over speed to nothing. Just a nice steady RPM.
The only thing changed on the engine was the crank and new main bearings.
I put my MT governor back on for the first flight just to save labor if all
was good.
ALL IS GOOD!
Don Broussard (Cajunwings) and I made the flight. He put the prop
through a number of throttle changes, both up and down, the rpms showed
only slight deviations (30-40 rpm) and within seconds was back at set
rpm.
So, for constant speed operation, the crank has to have the cross tube.
No one we talked to could explain the physics of why, just that they had
never seen one work without the tube.
At this point I don't care, my engine, governor and prop are performing
as designed.
Thanks to all the people that helped, Aircraft Specialties, Hartzell and
Lycoming. Don for the rebuild and flying.
Now for a chance to just fly.
is gone.
Time for update and conclusion.
Below is graph of RPM of take off this morning, from start of roll to 1000'.
This is after changing crankshaft to one with the tube across the inside
with a slot cut in the center of the tube.
Below is graph of RPM of take off from start of roll for 30 seconds with the old crankshaft with only
a hole in crankshaft wall, no tube.
As you can see, no sag, no over speed to nothing. Just a nice steady RPM.
The only thing changed on the engine was the crank and new main bearings.
I put my MT governor back on for the first flight just to save labor if all
was good.
ALL IS GOOD!
Don Broussard (Cajunwings) and I made the flight. He put the prop
through a number of throttle changes, both up and down, the rpms showed
only slight deviations (30-40 rpm) and within seconds was back at set
rpm.
So, for constant speed operation, the crank has to have the cross tube.
No one we talked to could explain the physics of why, just that they had
never seen one work without the tube.
At this point I don't care, my engine, governor and prop are performing
as designed.
Thanks to all the people that helped, Aircraft Specialties, Hartzell and
Lycoming. Don for the rebuild and flying.
Now for a chance to just fly.
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