Beechcraft C23 pilot reported a loss of engine power on climb out resulting in return to airport.

Attributes
ACN	1701453
Time
Date	201909
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Sundowner 23
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Cylinder Head
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 40 Flight Crew Total 350 Flight Crew Type 35
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Flied IFR from ZZZ to ZZZ1; engine began to make a strange noise on initial climb. Noise began to get more noticeable and then I noticed a vibration beginning. I canceled IFR and returned to my home field of ZZZ. When the mechanic removed the cowling to investigate he discovered the number 3 cylinder of my lycoming O-360 had sheared off all 4 of its deck studs and 2 of the 4 through bolts had nuts backed off their posts. The engine was overhauled in 2013 at [FBO] and had 200 hours since overhaul.

Original NASA ASRS Text

Title: Beechcraft C23 pilot reported a loss of engine power on climb out resulting in return to airport.

Narrative: Flied IFR from ZZZ to ZZZ1; engine began to make a strange noise on initial climb. Noise began to get more noticeable and then I noticed a vibration beginning. I canceled IFR and returned to my home field of ZZZ. When the Mechanic removed the cowling to investigate he discovered the number 3 cylinder of my Lycoming O-360 had sheared off all 4 of its deck studs and 2 of the 4 through bolts had nuts backed off their posts. The engine was overhauled in 2013 at [FBO] and had 200 hours since overhaul.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.