We Compared 172, Cherokee & Skylane Engines Past TBO — A Clear Winner

We Compared 172, Cherokee & Skylane Engines Past TBO — A Clear Winner On July 24th, 2026, Lycoming published Service Instruction 1009BF and moved Time Between Overhaul from 2,000 hours to 2,600 across the O-320, IO-320, O-360, IO-360, IO-390, O-540 and IO-540 families. Six hundred extra hours, delivered in a single document, with one conditional clause attached that moves the burden of proof onto the owner. Two of the three airplanes in this comparison run engines on that list. This video holds the three highest-volume piston singles in the American market side by side and judges them on what the documented record says their engines actually do past two thousand hours. The Cessna 172 Skyhawk and its four-cylinder Lycoming. The Piper PA-28 Cherokee and the airworthiness directive sitting under its wing. The Cessna 182 Skylane and the six-cylinder Continental that costs more for reasons unrelated to quality. The central finding is that hours are the wrong measurement. Camshaft and lifter spalling is the number one reason piston engines fail to reach TBO, and it is a disuse failure, not a wear failure. The Lycoming camshaft sits high in the case, away from the oil mist coming off the crank. When an airplane sits, that surface dries first. The used market pays its highest premium for low time and a hangar, which is the exact ownership profile that destroys camshafts. Every number comes from primary sources: Lycoming SI 1009BF and 1191A, FAA AD 2020-26-16 and the September 2024 proposed rule, the NTSB finding on the 2018 PA-28R-201 spar, and current shop and NDT pricing. The FAA priced the Cherokee spar inspection at $380 per airplane and the repair at $8,260 per wing spar across a fleet of 19,696 aircraft. The actual field quote runs closer to $1,000 before anyone opens a wing. The counter-evidence is in this video too, because it changes the verdict. Compression testing will not catch a failing camshaft. Oil analysis has the same blind spot, because the particles that matter migrate to the filter instead of staying suspended in the sample. The one procedure that finds it costs almost nothing and takes ten minutes at the next oil change. Chapters: 00:00 The Filter on the Bench 04:47 The Surface That Goes Dry First 07:43 The Wing That Came Off 11:02 The Only Honest Instrument References: Lycoming Extends Engine TBO to 2,600 Hours. General Aviation News. https://generalaviationnews.com/2026/... Lycoming O-Series Engine Overhaul Cost. Flying411. https://flying411.com/blog/lycoming-o... Lycoming Engine Overhaul Cost and Time to Expect. Flying411. https://flying411.com/blog/lycoming-e... Reliability-Centered Maintenance, Part 3. Savvy Aviation. https://www.savvyaviation.com/reliabi... The Cam Problem: Corrosion, Failures. Aviation Consumer. https://www.aviationconsumer.com/main... How to Care for Your Lycoming Camshaft. FLYING Magazine. https://www.flyingmag.com/how-to-care... Ask Paul: How would I know if my engine's cam lobes are pitted? General Aviation News. https://generalaviationnews.com/2024/... Airworthiness Directives; Piper Aircraft, Inc. Airplanes. Federal Register, January 15, 2021. https://www.federalregister.gov/docum... Airworthiness Directives; Piper Aircraft, Inc. Airplanes (proposed). Federal Register, September 23, 2024. https://www.federalregister.gov/docum... FAA Proposes New AD On Piper Wing Spars. Aviation Safety. https://aviationsafetymagazine.com/fe... FAA Issues Service Bulletin Updating Piper Wing Spar Guidance. Piper Owner Society. https://piperowner.org/faa-issues-ser... FAQ: PA-28 AD 2020-26-16. Aircraft Structural Inspections. https://www.asindt.com/pa28adfaq/ Maintenance Matters: Compression Testing. KITPLANES. https://www.kitplanes.com/maintenance... Cylinder Compression Checks. Cessna Owner Organization. https://cessnaowner.org/cylinder-comp... GAMA General Aviation Shipment Report, 2025 Year-End. GAMA. https://gama.aero/wp-content/uploads/...