If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Break-in for our newly overhauled towplane engine
Just wanted to fish for the procedures and experiences out there on this subject.
Our overhauler and our mechanic both say no towing for 10-18 hours.... We can do this, of course, but we are eager to get back to towing as soon as we can. Any experience or procedures out there that might get us towing sooner? But we will not compromise long term engine health.... Thanks in advance. Cheers, Jim |
#2
|
|||
|
|||
Break-in for our newly overhauled towplane engine
Seems a bit much......what needs to be accomplish is the ‘seating’ of the piston rings without glazing the cylinder walls, not being chromed.
To do this, ideally, is from the beginning, one run high idle for 1 min, shutdown and check for oil leak. Then, and here it gets fun, fill up with gas, start, quick mag check and takoff max power , then set 27/27 on the engine and fly around until you’re just about out of gas. Pay close attention to CHT stay within reason as dictated by your overhauler. The seating will be affirmed when oil consumption drops to nil and the CHT starts to stabilize somewhat lower (5hrs). Because all this was done at high speed, better cooling, we now fly at normal tow power and speeds and observe CHT , oil consumption for a 1-2 hours and if all is well....begin trial towing monitoring the engine (10 tows). The engine only cares about temp, and oil consumption is a clue to health. Your after tow letdown procedure is the most important part of the tow. I use the 20/15/10/ idle at 500’ increments of altitude method. Oil change and filter inspection at the 5/10/25 hour mark initially. Oil with a camguard additive is high on my list. You were advised ‘10-18’, meaning we’re waiting. For what? This should have been provided to you. Seating of the pistons, oil consumption stabilized, CHTs happy. Good news, weather is getting cooler for the break in. And you’re about to get tons of opinions and advice. Common sense will serve your club well. Take it all to your overhaul guy and come up with a plan He’s looking out for no. 1. After that.....tow away...just don’t let the engine know. 😜 R |
#3
|
|||
|
|||
Break-in for our newly overhauled towplane engine
On Monday, October 29, 2018 at 1:05:38 PM UTC-4, Retting wrote:
Seems a bit much......what needs to be accomplish is the ‘seating’ of the piston rings without glazing the cylinder walls, not being chromed. To do this, ideally, is from the beginning, one run high idle for 1 min, shutdown and check for oil leak. Then, and here it gets fun, fill up with gas, start, quick mag check and takoff max power , then set 27/27 on the engine and fly around until you’re just about out of gas. Pay close attention to CHT stay within reason as dictated by your overhauler. The seating will be affirmed when oil consumption drops to nil and the CHT starts to stabilize somewhat lower (5hrs). Because all this was done at high speed, better cooling, we now fly at normal tow power and speeds and observe CHT , oil consumption for a 1-2 hours and if all is well....begin trial towing monitoring the engine (10 tows). The engine only cares about temp, and oil consumption is a clue to health.. Your after tow letdown procedure is the most important part of the tow. I use the 20/15/10/ idle at 500’ increments of altitude method. Oil change and filter inspection at the 5/10/25 hour mark initially. Oil with a camguard additive is high on my list. You were advised ‘10-18’, meaning we’re waiting. For what? This should have been provided to you. Seating of the pistons, oil consumption stabilized, CHTs happy. Good news, weather is getting cooler for the break in. And you’re about to get tons of opinions and advice. Common sense will serve your club well. Take it all to your overhaul guy and come up with a plan He’s looking out for no. 1. After that.....tow away...just don’t let the engine know. 😜 R I agree with R. After 5 hr if everything is right, we're towing. No need to run close to $1000 worth of gas through it and incur a lot of no revenue wear. Plus that is a lot of pilot time. UH |
#4
|
|||
|
|||
Break-in for our newly overhauled towplane engine
On Monday, October 29, 2018 at 10:04:34 AM UTC-4, wrote:
Just wanted to fish for the procedures and experiences out there on this subject. Our overhauler and our mechanic both say no towing for 10-18 hours.... We can do this, of course, but we are eager to get back to towing as soon as we can. Any experience or procedures out there that might get us towing sooner? But we will not compromise long term engine health.... Thanks in advance. Cheers, Jim Depends on who did the overhaul and the test procedures. One of the best in the business was Joe Sylvia in Miami, now long gone. Test procedure after rebuild was to run on a test platform built on the back of an old flatbed truck. Joe would run the engine until the rings were seated, that would indicated a temp drop to normal temp range. At that point the engine was removed from the test stand and installed on the airplane. His advice was to go fly, and yes the CHT and oil temp are the two important factors. This whole process should take about two hours or less of run time. Go TOW ! |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
How to Break-In an Engine | Veeduber[_2_] | Home Built | 1 | July 11th 09 09:01 AM |
Engine break-in??? | Tri-Pacer | Home Built | 1 | September 26th 07 05:30 PM |
Which overhauled Lycoming 0-360 A4M Engine To Fit In My Archer ? | Roy Page | Owning | 7 | February 2nd 06 02:19 AM |
FS C172- JUST FINISHED- STOL kit and Overhauled engine with Brand New Cylinders | RWAC | Aviation Marketplace | 0 | March 15th 04 03:13 PM |
My newly overhauled Gyro! | Robert M. Gary | Piloting | 10 | March 4th 04 06:10 PM |