Importance of engine break-in ?
 

I'm pretty old school when it comes to engines, and believe that patience is a virtue regarding setting everything up on engines just right but recently, I've heard conflicting rumors that as new/ modern model aircraft engines are test run enough at the factory, to go ahead, mount your new engine and fly right out of the box as they've already.[8D]
Obviously there could be several factors to these rumors such as manufacturer of these new engines ie: 2 or 4 stroke, etc.
the New evolution engines for example are said to be good to go, but what about something like a Magnums, or OS ?
I have a new Magnum 91FS and am tempted to simply run it rich and fly, but I don't want to damage the engine or potentially loose a plane over being impatient.
Any thoughts on the factory break-in/ run proceedures vs. break-in at home ?
i'm interested to know what others out there are doing

RE: Importance of engine break-in ?
 

With the exception of Fox and Enya engines, I run a new engine (ABC, ABN) on my Tatone test stand just long enough to get the carb settings perfected, and then fly.

RE: Importance of engine break-in ?
 

You'll definately see a great difference....and specially with ringed engines. It is true that the tolerances are much closer than they were before, but the engines still need it. You won't get it to run at full power or reliable until the ring is seated.

Magnum 4 strokers are very well known around here to take a little bit more to break in. 3 Tanks won't take much time....take your chances...do the break in, and see how it performs..for the next one then you know what to expect from first hand.

Saludos,

Jorge

RE: Importance of engine break-in ?
 

Very simply put; there's nothing to lose by running a few tanks through new engine, except some fuel, but probably something to gain. the old ringed engines definitly needed a reasonable break in to seat the rings and cylinder. Most engines today do not have rings but will benefit by a few tanks of fuel run through them at a varying rich to lean setting prior to putting them in the air. It will take that much just to tune them properly. I have 2 evo engines and think they are misleading the public by saying no break in required. Also I have found it necassary to remove the restriction on Evo throttle to properly tune. Once done though they are great running engines. Just as with most things we each have our own opinions, those are mine.

RE: Importance of engine break-in ?
 

NF,


None of the run-of-the-mill production engines are pre-run at the factory.

Most are produced with CNC, so you can be sure the fit is very good and only a minimal amount of break-in is necessary.


The only engines that are pre-run, are probably those made by Jett, Nelson and other competition engine companies.
They are run prior to being broken-in, to verify they will perform within spec...
Also, some intricate engines; such as multi-cylinder, very dear units, are also pre-run, to ascertain they actually work.

RE: Importance of engine break-in ?
 

I have an Enya .45 series 6001 (two ring piston ) that I ran on the bench to set the carb and then flew. The engine performs like a champ. The piston and rings show no signs of galling.

RE: Importance of engine break-in ?
 

Even Fox takes less time to break in than they used too.

RE: Importance of engine break-in ?
 

Fox is using CNC machinery (piston and cylinder sets) as well as cranks.

RE: Importance of engine break-in ?
 

What are you out by running a few tanks of fuel through rich then setting the carb? A few bucks worth of fuel? Option 2 is to pull the engine out of the box, mount and fly and risk seizing an engine or overheating and screwing up several hundred in an engine and possibly loosing a plane.

I'll use a few bucks of fuel.

Mike

RE: Importance of engine break-in ?
 

That is why I run on a test stand before I fly. I have never damaged an engine yet doing this and I have engines that are as old as 50 yrs. The only dead sticks I've had were due to a bad plug or running out of fuel. I do what Ole Duke used to say, I keep my engines clean and not too lean. I believe in using engines that are above minimum size recommended so I don't have to run the pewaddle out of them.:D I have a Traxxas 2.5 with over 15 gallons on it so far as a result of my tuning and it has all original innards still.[X(]

RE: Importance of engine break-in ?
 

OS engines: one tank of fuel on the ground, adjust needles, and fly.

I found out that it is important to go easy on them for the first few flights. Keep it a tad rich, avoid nose up flights like they say in the manual. I ignored both of these on my most recent engine, just for giggles, and resulted in a dead stick after pushing the engine for about 5 minutes.

Of course I later learned the fuel I was using is garbage...

RE: Importance of engine break-in ?
 

Aside from the benefits mentioned in the previous posts, I find running engines an enjoyable pastime.

jess

RE: Importance of engine break-in ?
 

YES!!!

RE: Importance of engine break-in ?
 

"I love the smell of napalm in the morning" - or in this case Nitro!!!

Mike

RE: Importance of engine break-in ?
 

I like to spend a fair bit of time running an engine in on the test stand, first because I love running engines and like to learn what each engine needs to get one flick starts and second because even Jett say their engines need about 30 minutes to run in the conrod. I'm probably over cautious coming from a CL background when, if the engine happens to go lean in flight, you gotta wait until the tank runs dry :). With ringed engines (as are almost all 4 strokes) I really take my time and give them at least an hour on the bench.

RE: Importance of engine break-in ?
 

I think it's interesting that in forty years, Clarence Lee has not changed his ringed engine break in procedure at all.

The six images below are from the very first Engine Clinic column, which appeared in the 1/69 RCM.

In my next post I'll show the letter I got with my Lee Custom VECO a couple of months ago.

David

RE: Importance of engine break-in ?
 

...and the instructions with my Custom VECO:

David

RE: Importance of engine break-in ?
 

I have my concerns that during a flight the engine may be more prone to a lean run than on the ground due to unloading.

RE: Importance of engine break-in ?
 

Any engine will cool better in the air, And again if your engine is set where its supposed to be you won't have a lean run in the air.

RE: Importance of engine break-in ?
 

Jett recommends a bench break-in. They suggest simulating airborne RPMs by using a prop one inch smaller than normal. 30 minutes of rich running on the bench with the smaller prop, then mount the engine on the plane, switch to the right sized prop and go fly.

Tom

RE: Importance of engine break-in ?
 

Stick a thermocouple under the glow plug with some onboard readouts and see what you get on the ground and in the air.

RE: Importance of engine break-in ?
 

Thanks too all for the plethora of responses !:D
This type of communications is such a big part of what makes RCU so great !!!;)
Thanks again !

RE: Importance of engine break-in ?
 

Bolt the engine on the plane. Take it to the flying field and bolt the wings on to act as a vibration dampener and reduce airframe stress. Start the engine and run 2 or 3 tanks through it at a slightly rich setting. Tune the low speed needle for good transition after a 45 second idle. Tune the high speed needle for peak RPM and then richen about 200-400RPM off peak. Fly it.

RE: Importance of engine break-in ?
 

Yes, these new engines are machined in CNC machinery and it is not enough to use the engine parts direct from CNC machinery. All tool marks from lathe must be removed first, also all parts are grinded/lapped before use. The material in new engines are not same as in old iron engines and need short running-in and get all moving parts adapted togheter in perfect fit who are not possible to make better in tooling machinery.

RE: Importance of engine break-in ?
 

An engine may or may not run cooler in the air than on the bench. Factors like cowlings and the aerodynamics of the nose play a major role. You are correct that the engine needs to be set "where it's supposed to be". Far easier and safer to determine this setting on the bench, especially if you have duplicated tank size and location, fuel line length etc. as will be used in the plane.

jess