New IO-360 Break In

JC150 said:
Also, is 6 hours enough to take a family member flying? It seems to be running fine...
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Only you can answer that. You could probably find some that would say wait till you get 10 or 20 hours on it. I think my attitude currently is if you're looking at the situation and genuinely deciding its too risky to take your family up, shouldn't you probably stay on the ground yourself also?
 
On this last engine change and break-in on our Dakota, one cylinder stubbornly refused to drop CHT until the 10th hour ... and then it finally joined the gang and all is good.
 
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I'm going to take it up for another 4.5 hour flight. My friend says I should fly at 1,000' msl and run WOT/Full RPM/Full Mixture which looks like 93% power.

I personally feel like that is running it too hard. I'm curious what everyone here thinks?
 
I think you should pay more attention to the advice of Lycoming and your mechanic than your friend or stangers on the internet. Says some stranger on the internet.
 
Update: The engine has 40 hours on it now and I'm still not seeing a reduction in CHTs. My mechanic is not being any help to me. This is why I was so nervous about doing the break in and why I was asking for advice on here... but i'm confident I've done it correctly. Can I get any recommendations on what to do next?
 
I was told to look for the temp drop too. I scoured the logs and I never saw such a thing. My engines got 50 hours and is not burning oil, so it’s all good.

What’s your oil consumption?
 
JC150 said:
Update: The engine has 40 hours on it now and I'm still not seeing a reduction in CHTs. My mechanic is not being any help to me. This is why I was so nervous about doing the break in and why I was asking for advice on here... but i'm confident I've done it correctly. Can I get any recommendations on what to do next?
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Call it an indication error and fly it. I don't think I ever saw a drop in cylinder head temperature that I could identify. You flew the break-in hours off. Nothing to do now but fly it like its broke in and you get what you get.
 
I noticed an oil temp drop as I didn’t have CHT or EGT gauges on the plane I overhauled. If you do another compression test it will tell you if they are seated.
 
JC150 said:
UPDATE:

I put the first 6 hours on the engine. I leveled off at 3,000' and flew WOT and used RPM to change % of power. Full Rich Mixture.

My question is my CHTs are not dropping. I was told the rings are seated when I noticed a drop in CHT temps. After 6 hours there's still no change..

79%pwr (27"/2400rpm) 321/314/316/308
83%pwr (27"/2500rpm) 324/316/318/312
86%pwr (27"/2600rpm) 327/321/324/317

!
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I think you’re over thinking this to much with the temps, those are rather close. I recently broke in a new IO-390. I started with higher power setting, flying low, & rich. I did vary a bit at times, ‘mineral oil’ the 1st 25-30 hours. Later on when I started to lean more my CHTs came much more inline, but I still have up to 40-45 CHT temp diffence once stabilized. I talked to Lycoming about it and the Tech didn’t seem to think it was a big deal. Of course the cylinders themselves have variations due to position and cooling.

Part of this all comes from the accurate engine monitors many have. The more I read seemed to point to that 1st 10-15 hours being when most of the ‘break-in’ takes place. After 30 hours I went to regular oil, had a one change with mineral oil early on.
 
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