She’s Alive!!

ARFlyer

ARFlyer

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ARFlyer
Our 172 finally took to the sky today for her engine break in! It was a great day for it because we didn’t have a single bump until our descent back into home base.

Only two minor squawks out of the flight and a clean cowl which impressed our A&P. One squawk is our new CEIS fuel senders are reading 5 gallons or so to high and the right one is bouncing +/- 10 gallons in smooth level flight.

The other is the #4 started running about 100°F hot on both CHT and EGT after my half hour at 65% power. When I went full throttle for the last half hour the #4 skyrocketed to 1450/405 with the rest at 1300/360. Then on landing the #4 went 100°F colder then the rest until shut down. A&P wants to watch it as it was rock solid with the rest until that power increase about half way through the flight.

Besides that it was an awesome NASCAR style flight for 2 hours... :D
 

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AKBill said:
Nice engine, bet it preforms great in a 172
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Heck yeah! Climbs like a home sick angel! We actually got spooked by how quiet and smooth the new engine is.

Hiperbiper said:
Sounds like a fouled plug in #4...
That sounds like a nice combo.

Chris
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I’ll check it out! Isn’t it kinda quick for a fouled plug?
 
Rising EGT would be a sign that one of the plugs is not firing however you would not expect the CHT to climb. If it were injected your symptoms are classic for a clogged injector. I am not sure I would fly it much if this is a change in how the engine operated prior without taking a good look at the cylinder and valves. It’s not clear if it operated normally at high power prior to this event.
 
Jeff767 said:
Rising EGT would be a sign that one of the plugs is not firing however you would not expect the CHT to climb. If it were injected your symptoms are classic for a clogged injector. I am not sure I would fly it much if this is a change in how the engine operated prior without taking a good look at the cylinder and valves. It’s not clear if it operated normally at high power prior to this event.
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The engine is brand new. This was the break in flight. The data dump shows all EGTs in line until I added full power during the last 30 minutes. When I did that the #4 jumped away from the group and was constantly around 100°F hotter or colder then the group.
 
It’s unlikely both the EGT and CHT sensors would fail together and in the same manor. It might be that EGT is just high and the CHT is because that cylinder has glazed and did not break in. Lycoming recommends a minimum of 75% power for the first two hours combined with a shallow climb to keep temps low. You should however see a clear reduction in all cylinder head temps during the first hour. On takeoff were all cylinder heads temps relatively close? Did the hot cylinder increase in temp or did the other 3 decrease in temp? If the cylinder is glazed the only fix is to pull it and rehone the cylinder. You might also check for flashing and any other obstructions in the cylinder fins as well as insuring the baffling was all correctly in place.
 
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ARFlyer said:
Heck yeah! Climbs like a home sick angel! We actually got spooked by how quiet and smooth the new engine is.



I’ll check it out! Isn’t it kinda quick for a fouled plug?
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Just broke in a couple IO-360 cylinders and had one cylinder oil foul the plugs during the couple hours. After that seemed to be fine. From what I can tell this isn’t that uncommon.

Brian
 
A hot cylinder in a carbureted engine would seem to indicate a vacuum leak in an intake runner, past the carburetor, although there are other problems that could account for it. I would find and correct the problem before continuing the break in, but that’s just me.
 
A vacuum leak typically shows up at low power settings. At high power settings there is no vacuum to pull air through the leak. 65% might be low enough however to see a rise in EGT and CHT so worth a look.
 
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