Oil change after engine work

Removed cylinder #3 and had it overhauled. The engine has about 950 hours TT and that cyl had some oil blow by (always had a oily wet plug). I changed oil to mineral oil after repairs. My question is, how long should I run that oil before changing it? I did all the recommended break in procedures. Seems that it burns more oil now (although plug is dry) but I?m hoping that part of the break in. I?ve got 15 hours in the break in oil.

Also, is it worth doing oil analysis? Or will there be high metal content from the ring break in?

I'm not an expert, but I know that oil consumption is normal during engine break in. I also know that you are not supposed to do oil analysis during the break in process because your numbers will be through the roof because the engine is still wearing in. I think I recall 10 hours being when you are supposed to change the oil after a break it, then normal intervals after that.

5-10 hours on the oil with a new or overhauled engine. I would probably not do it that early after replacing one cylinder if I had an oil filter. The debris load should not be that high.

Larry

I have always kept operating with mineral oil until I saw a noticed decrease in oil consumption. On our O-540 it took as much as 25 hours to see the drop in oil consumption.

Thanks guys! Just another reason I love this forum!

Robin8er said:

I'm not an expert, but I know that oil consumption is normal during engine break in. t.

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This is generally not true, especially during the first hour or two. However, if you bought a new engine from Lycoming, you may not notice much consumption, as they do a short ?run-in? at the factory, so you?re not starting from scratch.