Engine Break-In

My new engine from AeroSport Power, IO-375-M1S, needed 15 to 20 hours of break-in. This required a high power setting, 25″ of manifold power, and 2300 RPM. They didn’t want me varying the power settings any more than needed, like for things like slow flight, multiple take-off’s & landings and such. So I spent the last 21.1 hours flying either close to my home airport or on a 200nm cross country circle that kept me within the 40nm radius I’m restricted to during the first 40 hours of flight called phase 1.

Today I finished the break-in and had no issues, oil burn over this time has been less than one quart and that happened earlier in the break-in period.

Part of the engine I needed to pay attention too was the temperatures of the cylinder’s. So I kept an hourly log of those and put them to a graph. I’m guessing that where you see the lowering of the average temps around the 4th hour is where the piston rings finally seated themselves but not for sure. Either way I’m glad this period is over and I can now move on to the tasks that I need to complete so I can get out of phase 1 and stretch the legs of this awesome machine!

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