Oil consumption during break-in

Bsquared · #1 01-12-2021, 06:25 PM

I am running a stock 390 and have been following the recommended break in.....long flights At WOT and 2500 rpm. At 6500 feet that gives me about 72% power..... well above the 65% recommended min. I am right at 20 hours and my CHTs and oil temps are good but I am still burning about a quart of oil (AeroShell 100) every 4 to 5 hours. Is this common? I have heard that it can take over 50 hrs to break in the 390. The belly is clean so not going out the crankcase vent.

BobTurner · #2 01-12-2021, 06:44 PM

Quote:

Originally Posted by Bsquared

I am right at 20 hours and my CHTs and oil temps are good but I am still burning about a quart of oil (AeroShell 100) every 4 to 5 hours. .

Honestly, this is not so good. I would have suggested flying lower, to get higher MP and also better cooling. Are you keeping the oil level topped? Try keeping it at, say, 2 or 3 qts below max, see if things improve. Some engines just like to throw out the top 2 qts or so. But otherwise, grit your teeth and prepare yourself for a re-hone.

Bavafa · #3 01-12-2021, 06:47 PM

As a point of reference, I burnt about 1 qt for every 7-8 hours and I keep it at 7 qt and add a qt when it goes down to 6.

rocketman1988 · #4 01-12-2021, 06:58 PM

I am breaking in my IO-540. Just did the first oil change. Used about 2 quarts in 10.5 hours. Engine manufacturer said this was within reason. Oil temps right around 190. Power used around 65%+.

Ironflight · #5 01-12-2021, 07:13 PM

I my opinion (one that has been built from talking with many of the noted engine experts in the industry), 65% is way to low to seat rings - you really want to get the power as high as you can - 80% is what I shoot for (successfully). It is very problematic breaking in engines here with a field elevation of 4400’ in the summer - almost impossible to get high enough power levels.

You want high power and as good of cooling as you can get to avoid glazing the cylinder walls. I am with Bob Turner (above) - you might well be glazed at this point.

Paul

Arablenz · #6 01-13-2021, 02:32 AM

I am at 58 hrs and stock io390 on Phillips M oil for running in and have used 1 and a half quarts for the last 14 hours. I have been running 75 percent power or better except for some testing through the 10 to 30 hour period for flight test evaluation.
I have read the lycoming recommendation that it can take 100 hrs. I am no expert but my oil usage is reducing still so don’t give up hope.

mountainride · #7 01-13-2021, 07:51 AM

I too was really concerned about my oil consumption on the IO-390 A3B6 on my -14. I was going through a qt every 4 hours and running it as hard as I could the entire time in Colorado. I was running more like 2600 RPM and trying to fly as much as I could out east below 5500 which is tricky here in Denver. I would lean for best power. LOP operation didn't start until hour 40 or 50. It got to the point where I had borescoped the cylinders and even called Lycoming.

They recommended I keep running Mineral Oil past 50 hours. I ran mineral oil for 85 hours My oil consumption remained high until 50-85 hours and it was still around a qt every 5-6. I switched over to Phillips XC and am now on my second oil change and at 140 hours I can now say my oil consumption is perfectly normal. I had my dipstick at 6 qts for the start of my trip and after flying 4 hours I was a 5 3/4 the next day. I am adding 1 qt every 7-10 hours now but also generally running lop 2350ish RPM and 55-60% power.

I think this engine takes longer to break in than others. Accurate measurements should be taken before flying after the oil in the case has had the chance to collect in the sump. I keep my oil level at 6 qts.

Tom023 · #8 01-13-2021, 08:16 AM

Same story here, 4-5 hours per quart on Aeroshell 100 mineral oil until about 80 hours running low and very hard. I was concerned at 50 hours and told to continue running mineral to 100. At about 80 hours consumption started to drop to about 6.5. I’m on my first fill on Phillips so don’t have a good number but am hoping for some improvement. Not much oil on the underside.

There are a couple of other threads about oil consumption with these engines where it seems like 6-8 hours per quart is typical. I don’t know if it’s just wishful thinking, but it does sound low to me still compared to the 360 I had in my Grumman Tiger which was in the 20 hour range.

BillL · #9 01-13-2021, 08:16 AM

Have you already changed oil once?

What is your oil level checked before starting each day? What are you shooting for? Mine will burn more oil above 6 qts on the stick but not much lower than that.

Jimzim · #10 01-13-2021, 08:57 AM

Quote:

Originally Posted by Ironflight

I my opinion (one that has been built from talking with many of the noted engine experts in the industry), 65% is way to low to seat rings - you really want to get the power as high as you can - 80% is what I shoot for (successfully). It is very problematic breaking in engines here with a field elevation of 4400’ in the summer - almost impossible to get high enough power levels.

You want high power and as good of cooling as you can get to avoid glazing the cylinder walls. I am with Bob Turner (above) - you might well be glazed at this point.

Paul

I am faced with having to break in a new Lycoming 180 this spring in Denver. The last engine I broke in on my RV7 the cht’s were a big problem and I had to pull the power back just after takeoff to keep them below 430ish. MP ended up at 20 inches or less, most times.
And yes, I did everything I could to insure proper baffle sealing, engine timing, etc...
My question is, what can I do to properly break in my new engine under those conditions? I have considered trying to contact Lycoming to see if more run in time on their stand might be available. Not sure if they’ll do that.
The last thing I want to risk is the long term health of this engine.
Suggestions appreciated!
Thanks, Jim