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Initial idle and fuel servo settings for overhaul

Majorpayne317641

Well Known Member
I am closing in on completing my overhaul engine build on my IO-360. I have a precision airmotive EX fuel servo that was rebuilt by them from my old engine. The question is are there any settings for fuel and idle speed that work for most engines as a starting point? Or is that already set by airmotive? I have their directions on how to adjust it, just want to know if anyone has any tricks for first start on a new engine that’s never been run. I have not run it on a stand. Thanks!
 

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Run-In vs Break-In

This info may be of interest since your engine has not been run on a test stand, so the run-in (and break-in) are up to you.

Run-In vs Break-In:

Ref: https://www.continental.aero/xPublications/xService Bulletins/Experimental PMA/SIL012/
"III. RUN-IN vs. BREAK-IN

Engine overhaul shops (and new engine manufacturers) typically run-in all engines for a period of one to two hours prior to release for installation in the airframe. However, run-in was never intended to be a complete break-in. The objective of the run-in is to:

1. Verify the engine meets rated power specification

2. Correct any oil, fuel, or induction leaks

3. Check and adjust engine fuel system

4. Check and adjust engine oil pressure

After run-in, the engine is released to the installer who provides the airframe, baffling, fuel settings, and all aircraft interface considerations. Break-in is not complete until the engine oil consumption has stabilized and many hours of operation have elapsed."​
Mahlon (Russell) has published engine Run-In and Break-In instructions in various places on the 'net, including VAF. Here is one:


And Mike Busch's presentation on engine Break-In:

 
This info may be of interest since your engine has not been run on a test stand, so the run-in (and break-in) are up to you.

Run-In vs Break-In:

Ref: https://www.continental.aero/xPublications/xService Bulletins/Experimental PMA/SIL012/
"III. RUN-IN vs. BREAK-IN

Engine overhaul shops (and new engine manufacturers) typically run-in all engines for a period of one to two hours prior to release for installation in the airframe. However, run-in was never intended to be a complete break-in. The objective of the run-in is to:

1. Verify the engine meets rated power specification

2. Correct any oil, fuel, or induction leaks

3. Check and adjust engine fuel system

4. Check and adjust engine oil pressure

After run-in, the engine is released to the installer who provides the airframe, baffling, fuel settings, and all aircraft interface considerations. Break-in is not complete until the engine oil consumption has stabilized and many hours of operation have elapsed."​
Mahlon (Russell) has published engine Run-In and Break-In instructions in various places on the 'net, including VAF. Here is one:


And Mike Busch's presentation on engine Break-In:



Thanks that was helpful. I appreciate the links.
 
Anyone else?

Also, now that I saw the run in/break in slide…it got me thinking as to why everyone else recommends very short taxi and immediate balls to the wall for an hour of flight? I like this method more, it is also very similar to Superior’s very own overhaul manual that gives a test routine to run in the engine on a test cell or an aircraft prior to first flight.
 
Brake in

I would follow Superiors break in procedure.
The idea is to seat the piston rings to the cylinder walls.
For this to happen, high cylinder pressure is required.
If you run the engine on low power / rpm for an extended time there is a risk
of glazing the cylinder walls. Glazing requires removal of cylinders and honing them.
Be sure to pre-oil the engine before first start. Se instructions for that.
Short ground run to check for fuel/ oil leaks.
Climb on full power and rich mixture to safe altitude 3000 ft GND.
Run at 75% power 2400/ 2500 rpm for at least one hr.
Do not let cylinder temperature go up over 430 F.
Oil temperature will be warmer than usual for the first hours, expect to see
up to 220F.

Good luck
 
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