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Engine Break In Lycoming YIO-360-M1B

fbrewer

Well Known Member
Members,

We are just about ready to do our first start of our factory new Lycoming.

Included with the engine documentation were reports of two test runs on the motor:

Test 1 : duration 30 minutes

2 Runin @ 1500 for 5 min
5 Runin @ 1800 for 10 min
8 Runin @ 2200 for 10 min
11 MagChk @ 2200 for 1 min
15 Idle @ 0 for 4 min

Test 2 : duration 31 minutes

2 Airflow @ AF-700 for 4 min (CHT = 410.4)
4 Airflow @ AF-900 for 4 min (CHT = 437.5)
6 Airflow @ AF-1000 for 4 min (CHT = 445)
8 Rated @ Rated for 15 min (2722 rpm, 27.5 mp, CHT = 439.4)
11 Final_Idle @ 0 for 4 min (CHT 331.5)
13 Manual @ N/A for 0 min)


Other than the rated power test for 15 minutes, I have no idea what the other test in Test 2 were about.

Can anyone add more information?
 
Members,

We are just about ready to do our first start of our factory new Lycoming.

Included with the engine documentation were reports of two test runs on the motor:

Test 1 : duration 30 minutes

2 Runin @ 1500 for 5 min
5 Runin @ 1800 for 10 min
8 Runin @ 2200 for 10 min
11 MagChk @ 2200 for 1 min
15 Idle @ 0 for 4 min

Test 2 : duration 31 minutes

2 Airflow @ AF-700 for 4 min (CHT = 410.4)
4 Airflow @ AF-900 for 4 min (CHT = 437.5)
6 Airflow @ AF-1000 for 4 min (CHT = 445)
8 Rated @ Rated for 15 min (2722 rpm, 27.5 mp, CHT = 439.4)
11 Final_Idle @ 0 for 4 min (CHT 331.5)
13 Manual @ N/A for 0 min)


Other than the rated power test for 15 minutes, I have no idea what the other test in Test 2 were about.

Can anyone add more information?

AF figures may be cubic CM/Min and would refer to the amount of air ingested while running. 1000 CM3/min (350 CFM) sounds about right for a 360 CI engine spinning 2700 RPM.

Kind of surprised they let the CHT's get that high. I would think those were near glazing territory, but apparently not.

Larry
 
I just recently did my first start and made lots of mistakes that the good folks at VAF helped me work out. Used to carbs and auto fuel injection. Following mistakes:

1. Cranking engine without researching IO start techniques.
2. Turn on boost pump and leave on. Great way to dump your fuel from sniffle valve to ground and flood engine...on only about 2 seconds until fuel pressure starts raising. Then start with part throttle and mixture lean and then richen to keep it running.
3. Assuming since engine was run that idle and idle mixture were set correct. Since my FI appeared new sealed in a box, Lycoming must have run it with a test FI. Mine was so rich it would stall the engine if you let RPM drop below about 1100. Adjust until a slight idle RPM increase when leaning for shut down.

If you have a CS prop, I had an overspeed and thought the prop high RPM limit was set wrong. Actually it was the governor. Hartzell said set prop control to 2700 at full power take off and don't change the control. Land and adjust governor screw to match position and then readjust cable.

I don't have many hours on my plane yet so I'm still running at 65-75% power. I've found it to be stressful breaking in a new engine on first flight. I did wide circuits at altitude around the airport for about 2 hours without wheel pants still seeing 140-150 knots, not really what I wanted to do without a tested airframe.
 
Scott,

Thanks for the tips. I am also nervous, yet excited for the first start. Your recap will help minimize my mistakes also.
 
I did the fuel flow testing and then since fueled did an unplanned start attempt. Darn lucky I did not have a fire since I had the sniffle line dumping direct upon exhaust... never occurred to me that it would dump fuel, I guess I thought crankcase oil like the breather. Luckily I had the foresight to have spotters with fire extinguishers to tell me I was dumping fuel on the exhaust. First task was to reroute the overflow line to high between the exhaust pipes.
 
OK, we just finished 5 hours of flight on our new YIO-360-M1B.

On the first flight (1.9), we had differences between CHTs at 75% power at 5,000 ft. OAT was about 70 degrees at altitude.

#1: 333
#2: 349
#3: 369
#4: 285

On landing, we pulled the cowl to inspect for leaks -- none!

We examined #4 CHT probe and found the spring was not inserted properly and thus the probe was loose and not fully inserted.

Additionally, we added metal tape to the #1 cylinder (bottom half) and tape to the #2 cylinder (bottom 25%). I will add a picture when I can remember to take it :)

At any rate, on today's flight which took us over the 5 hour test period for a major change, went off very well. 5000' OAT 70, and WOT (26.5 inches) with RPM at 2500. BTW, we are mostly running at 75% power and occasionally 65% power, this WOT test was just to see the temps.

#1: 344
#2: 337
#3: 337
#4: 329

We burned 1/4 qt in 1 hours. So, I don't think we are broken in yet. We would like to get to better than 1 qt in 10 hours for oil consumption.

My question to the brain trust is when can I start running LOP?



#1:
 
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