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New clyinder break in

SEFlyer

Member
Just curious about peoples experience breaking in new cylinders. Did you see a noticeable drop in cht? How many hours of using no oil us considered "stabilized " oil consumption. Thanks
 
I replaced cylinder #1 in February. It's steel. I expected to see high temps during break in but, honestly, I didn't really see that much difference, maybe 20 degrees and that was only for about the first 30 minutes or so. From then on, all temps were about the same. I followed the break in procedures to the best of my ability and after 100 hours, all is well.
 
Depends on what the cylinder wall is made out of and how much power you are producing.

On steel cylinders, I have seen a 20-degree drop in CHT at right around 20-minutes with full throttle, max RPM, and no more than 1,500' AGL. (Saw this three different times over 20+ years.)

At first oil change, between 5 and 10 hours, there was less than one quart oil used. (Maybe a 1/4 of a quart was used.) Next oil change was at 25 to 30 hours (since new cylinders) and running 75% power or more except for landings and taxi, I saw no noticeable oil used. (Anything less than one-quart, I am calling no noticeable oil used and no oil added.) Power is kept at 75% power or more varying manifold pressure and RPM about every 15-minutes. I will run over square using power setting that are on the Lycoming power chart.

I typically try to run 75% power as much as possible the first 100-hours. With spin on oil filter change and adding 7-quarts (shows 6.25 on stick after running), I have not added any oil typically before 35 to 45-hours during the first 1,000 hours. I do not add any oil till it only shows 5-quarts on the stick. I typically just change the oil instead of adding or waiting to change at 50-hours.
 
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