A&Ps Opinion on Engine Break In

[Pearson]

Re: A&Ps Opinion on Engine Break In

It all sounds good. Thanks for the advice. Tim where do you live that is 4500' elevation? I used to fly Lears out of Klamath Falls, Oregon for the guard unit there. It was 4100' elevation. Not too many airports out here at 4500'. I guess if you want to cruise at 3000' you have to have one of those granite boring props.

[astjp2]

Re: A&Ps Opinion on Engine Break In

Ogden is 4470, I went into Smiley Creek, 7700'msl on a warm summer day, almost didnt make it out, caught a down draft and it amost blew me into the trees at Galena Pass.

[Jim Hartley]

Re: A&Ps Opinion on Engine Break In

My experience on break-in of new cylinder/piston assemblys was positive. Last spring with an ambient temperature about 25 degrees at 465 feet MSL and below zero degrees at 10,000 feet MSL. I took off in a full power climb to 10,000 feet with a fairly steep angle to keep rpm at redline. Approximately twenty minutes to altitude followed by a shallow descent at high cruise to keep engine temperature up for another twenty minutes and for another ten minutes at cruise to stabilize engine temperature.Then I carried as much power as I could with a high drag slip to a landing. I do not think I saw below 1800 rpm until shortly before touch down. I saw a maximum oil temp of 190 degrees during climb and I used one quart of oil from the six quart sump. The oil consumption has been negligable since that first flight and I have about 90 hours since the top overhaul. I think that the engine break-in was complete after this flight,however for fifty hours I avoided short flights and low power settings.

Jim

Marty,

That has a lot of interesting info in it. But it doesn't say anything about after the second hour of operation. It just says during the second hour to operate between 65 & 75% power. I always thought it took 25 to 50 hours to break in an engine.

[fearofpavement]

Re: A&Ps Opinion on Engine Break In

The important thing is to run the engine hard for the first few hours. Most engine TBO times are calculated at rated hp. Flying an aircraft at lower power settings does not make the engine last longer in my opinion. It does use less fuel which is a good reason for less than max power.

Think for a moment about your power settings on the engine. What is take off rpm? Now let's consider your lawnmower engine which runs at 3,600 rpm. your car at 2000-5000 rpm and your chainsaw at about 13,000 rpm. An airplane engine even at full rated power is running pretty slow so don't baby it.