He says he was cruising at 5500' and the engine just started running bad and rattling so he landed at the nearest airport.
After an uneventful landing, he parked the plane and noted the same rattling noise.
As I hopped into plane to go pick him up, he had enough time to remove all the rocker covers. Nothing amiss there.
Pulling the prop through, all 6 cylinders had good compression.
A shop on the field had a spare oil filter so they yanked his off and cut it open. Nothing amiss there, all looked normal.
He cranked it with the starter and it just sounded funny, you could hear the "rattling" and something wasn't right.
We tied down the plane and he was gonna have to come back another day with some tools and more time to see if he can diagnose the issue.
His is the blue one and he parked next to another broken Stinson sitting on the ramp.

He went back today and could tell something wasn't right when he was turning the prop. He removed the starter and when the prop was wiggled, the gear off the crank that engages the starter DIDN'T MOVE!
He removed the top crankcase cover which is uniquely Franklin and low and behold the crankshaft was broken between the #5 & 6 rod journals, near the front of the engine.
Crazy that this engine held together at cruise, approach, landing, and taxiing. He has a guardian angel for sure.
Next options are to rebuild the Franklin 165 or go for the STC with the Franklin 220 and constant speed prop. One thing is for sure, the plane needs to be trailered home.
I told him to buy a lottery ticket because he got really lucky that this airplane and engine took care of him like this.
Here's a video of the carnage in action.
https://youtu.be/BXIWhytrgGY









