Could someone give me some advice or just tell me how to break in a ringed nitro air plane engine? the engine is a GMS 120 using 15% nitro and 16% castor/synthetic oil

Download any of SuperTigres manuals and it has a breakin proceedure for their motors. Doesnt GMS have a website?

You might get several differing opinions...let's see, aye?!
My method is just to run the first tank thru as rich as possable and still stay running. Sometimes I'll leave the plug battery on for awhile...meaning it's running so rich that if you take the batt. off, it'll quit on you.
Then lean it out some for the next tank, so that the plug batt. is not required, but still quite rich.

I will generally just run a couple- three tanks through an engine on a stand, then fly it...because I think extended test stand running is just a waste of fuel.
If you can get the carb adjusted to give you a decent idle and transition, then put in in the airplane and fly it, because it will get better cooling airflow there. (unless it's in a tight cowl or something )

I do it pretty much the way proptop said except I like to run them for about an hour ending up in a rich 2 stroke then a few flights starting at that same setting but a bit leaner each flight. Also I'd use a lot more oil than that 16%, at least 20% or more.

I break in engines using the manufacturer's recommendation. They made it and I would think they know how to break one in.

Running ringed engines that rich is harmful, non-productive, and a waste of
fuel. Whomever it was that started the rumor/procedure that ringed engines
need a super rich breakin, didn't know what he was talking about.

Running the engines that rich will keep them from breaking in, meaning seating
the ring. Keep in mind that we are running 4-5 times more oil than a regular
engine. If you run a ringed engine too rich, too long....you will glaze the cylinder
wall and the ring will not seat, or it will take forever to seat. You will have an
engine that will not produce full power, or idle well because of excessive blow-by,
and low compression.

FBD.

That's fine if you buy a new one in the box but a lot of guys pick up a new engine without the box or instructions. But even some of the manufacturer's recommendations are so vague you can't figure out what they mean. I ran in my Rossi exactly by the recommendations, that means I had a "greasy" exhaust

All:

Excerpt from my "Saito Notes."

Quote:

Break in of a fresh engine
A piston ring is seated in the first few seconds of engine running after its installation. This holds from the smallest to the largest of ringed engines, and is dependent on cylinder pressure to force the ring against the bore. Therefore, the initial running should be done at a high power setting.

My way is to allow the engine a few seconds to come up in temperature, then I immediately peak the mixture at full throttle, then right back to idle. For the first few minutes of running the engine goes to full throttle for about five seconds, then back to a rich idle for twenty. This gives me the high cylinder pressure to seat the ring while at full, and then at idle more oil is spread on the working parts.

After these first few minutes I'll go back to full and get about 800 rpm rich drop, then lean the idle a bit but not all the way, and put the engine in a plane. Over the next hour or two I'll slowly lean the idle, and bring the HS closer to peak. After a couple hours total time the engine is all ready for extended high power, and I've been able to fly the fuel through the engine instead of oiling the grass at my house. Or not oiling the grass as much as many do.

Not per most manufacturers, but it works for me.

Bill.

Thats funny, because a lot of manufacturers tell you to run an ABC engine stupid rich for initial break in. And we all know what that does to an ABC engine. Don't we?

Manufacturers tell us to run our engines overly rich because that gaurantees that the connecting rod bushing won't seize on the crank pin. They could care less what that overly rich break in does to long term engine performance, they just want to avoid a warranty claim from a stuck rod bushing. It's strictly a C.Y.A. thing on the part of the manufacturers.

I haven't read an engine manual since my first new one that I bought over 8yrs ago. I read the manual on that engine and did the break in according to the manaul and I effectively ruined the engine. It was an OS 120 Surpass non-pumped engine, and I broke it in just like the manual said. Word for word. That engine turned into one of the biggest POS I have ever had the displeasure of owning. That was purely the fault of the break in. I didn't know it at the time. I thought 4-strokes just sucked. It wasn't untill I discovered RCU and started reading posts from guys like FBD and W8YE that it finally dawned on me why that OS Surpass was such a POS. It was because I broke it in according to the manual. Who better than to tell you how to break it in but that manufacturer--right? Total BS.

Didn't take me but one engine, and $350 to figure out what was going on.

My break in procedure NOW:
I add 4oz of castor to a fresh gallon of 5% Omega fuel and break them in like I plan to run them. WFO and screaming bloody murder with a small diameter--high pitch prop that will let them run at MAX rated RPM or darn close to it for a couple tanks. Haven't cooked one yet, or had a turd engine from my break in procedure in the last 8yrs.

Break it in like your trying to break it. If it breaks, then send it back. If it doesn't break, then it never will. Babying an engine with too much fuel and low RPM isn't really babying it at all. It's ruining it. They are made to run, and run well. Start it up and run it WFO with the main needle about 1/2--3/4 turn rich with a tiny prop and let it scream.

The guy that started that "rumor was Clarence Lee, Dave Geirke and the manufacturers among others.

RCpilot,

And which manufacturer says to run an ABC engine rich at anytime? Not OS, Enya or any of the other major manufacturers. I have had three OS120 Surpasses, two FS120's and dozens of other OS four cycles and two cycles and broke them in according to manufacturers instructions and EVERY SINGLE ONE was/is a great running engine.

No engine manufacturer suggests rich running during break in? Not OS?

You obviously haven't read the manuals--yet you subscribe to that very theory on breaking the engine in.

Well, here's a direct quote from the 46AX manual--straight from the OS website.

Install the engine with the propeller intended for
your model. Open the needle-valve to the advised
starting setting and start the engine. If the engine
stops when the glow plug battery disconnected,
open the needle-valve to the point where the engine
does not stop.Run the engine for one minute
with the throttle fully open, but with the needlevalve
adjusted for rich, slow !QUOT!four-cycle!QUOT!operation.

Thats an ABC engine, and the manual specifically tells you to run it !QUOT!four-cycle!QUOT! rich for 1 minute upon initial start-up. Are you sure your reading the manuals?

Now, here's a direct quote for the 120AX, a ringed engine:

Install the engine with the propeller intended
for your model. Open the needle-valve to the
advised starting setting and start the engine.
If the engine stops when the glow plug
battery is disconnected, open the needlevalve
to the point where the engine does not
stop.Run the engine for one minute with the
throttle fully open, but with the needle-valve
adjusted for rich, slow !QUOT!four-cycle!QUOT!operation.

Same thing. Run it 4-stroke rich for a minute.

I don't care what the manual says. I trust guys like W. Robbinson, FBD, and W8YE more than I trust a corporate giant looking to cover their butts on warranty.

Here's a direct quote from a ST engine manual:

The engine should be running at full throttle, but running somewhat
rough, with a lot of fuel/oil being discharged from the muffler. This is
because the engine is running in a very rich condition–that is, more than
enough fuel is running through the engine than is needed. Run the
engine at this setting for at least five minutes.

Sounds like 4-stroking rich to me.

So, lets wrap this up:
I pointed out that the practice of manufacturers telling us to break our engines in excessively rich is simply to cover their own butt against warranty claims. It is not necessary to run an excessively engine rich, and in fact it can hurt the engines long term performance.

You countered my statement by claiming that you know of no engine manufacturer who recommends this overly rich break in.

And I just gave you 3 perfect examples of manufacturers doing just exactly that.

loughbd:
I'm happy that you've had good luck with your engines by running then in according to the manual--although I think you may need to brush up on those procedures, because it appears you've forgotten just exactly how the manufacturers tell us to do the break in.

But, myself, and a lot of guys put considerable effort into educating new hobbyists on the PROPER way to break in a glow engine. When you come into the forums with a combative attitude, and act like we're all stupid for not just doing it according to the manufacturers recommendations, it doesn't help. We want people to have fun, and we want them to break their engines in the right way and have good success with the hobby.

The generally poor attitude in your tone is completely counter-productive to the education process for these newbies. Because, in fact, the manufacturers are NOT giving us the best advice here. If you want to follow the manual--then good. Have fun. But don't post inflammatory remarks that hint at ignorance on the part of the rest of us. It doesn't help the newbie, and your, well, your just wrong.

I believe that "endless breakin's" with gallons of fuel is a waste of time and money. I simply run a couple tank fulls through the engine to get it dial in. Leave it just a tad rich and fly the darn thing. Everybody has their own way. Mine works for me and all my engines run just fine.

Adding fuel to the fire here in that just because and engine has been broken in for 6 months on a test stand and 20 gallons of fuel does not mean it will run any better than mine if a person cannot properly tune it. I fly at a public field and there is a very healthy percentage of pilots who "think" there engine is straight vs those of us whose engines are.

Tone?? Hard to tell the tone of something unless you can hear it.

QUOT?? What does that mean?

I seem to remember that the original question was how do you break in a RINGED engine.

Let's re-cap:

It is about breaking in ringed engines.

FBD and W. Robbinson both gave good reasons why it's not necessary to run a ringed engine excessively rich for extended periods of time.

You claimed that you are breaking your engines in according to the engine manuals, and you insinuated that people who don't break the engines in according to the manual are stupid.

So, I quoted 3 different engine manuals to make my point that the manuals aren't written in the best interest of good engine performance. Rather, the manuals are written to cover the manufacturer from warranty claims.

It simply is not true that ringed engines need an excessively rich or prolonged break, as both you and the manufacturers suggest. By claiming to break your engines in according to the manuals, you are endorsing the practice of an extended break in period. But, I seriously doubt that your really reading the manuals. Your remarks were only meant to inflame and stir the proverbial pot.

So, I took it upon myself to discredit your remarks--which BTW, I did very well-- in the interest of promoting the techniques described by FBD and W. Robbinson.

Are you still confused? Go back and read the thread from the beginning and let me know if further explanation is necessary.

I didn't insinuate anything. You are reading something that isn't there into my post. Quot says I. Yup, I'm an inflamer from way back. Shazaam, we're all inflamed.

Yup, listen up everyone. When you buy a new engine, whatever the brand, the first thing you should do is throw away the instructions because all those greedy, corporate, slime, manufacturers are trying to do is get you to follow the instructions so you destroy your new engine. That way they can sell you another engine. Very sneaky they are. We have their number now.

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Which leads me to believe that if it really mattered all that much, the manufacturers would make it a lot clearer, since they, or their sole distributor lackies, will have to repair the engines at their own expense.

I'm looking for some grease to run through my three new Rossi's. I wonder if Taco Bell is open at 0331? <G>

Yes, nothing but good for the ones where the manufactures recommend such rich running. I see no manufactures that recommend running them as lean as possible.

Every manufacture says to run them rich. Some including OS say to run them in four cycle, or near four cycle on SOME of their engines. The only thing to worry about with ABC engines is throwing a rod with severe pinch designs. Most of the modern engines do not have this problem. Composition and the amount of taper determine the best break in procedure, it is best to observe the manufactures instructions as you said.

Well gee...at least the first line in my first post was right!

Anyway...when I run that first (just one mind you ) tank through excessively rich, it's mainly for the connecting rod...and being so rich, it sure doesn't take long to go thru that tank...like maybe a couple - three minutes? (don't mind me...I'm just trying to CMA )

Edit: I have a 6 oz. tank on my engine test stand, and a large engine will obviously go through it quickly. If I'm running a .25 for example, I won't even run a whole tank through it...I will run it long enough to get a baseline, and set the carb for a decent idle and transition.

This is what I love about RCU's forums. A person posts a simple question and the "gurus" light up the thread with there bickering and arguing about who is right and who is wrong. The final outcome is that the individual who asked the question, after trying to filter all the BS out of the arguing back and forth, comes away with no answer to the question.

A clear, concise question deserves a clear, concise answer. Each of you "know it alls" need just post your opinion on on the "right" way to do it, then, back off and STOP arguing with each other about your way being the best.

By the way, where is the moderator while all this is going on?

doubledee

Apparently you missed the clear, concise answer. Follow the manufactures directions. I don't think any of the gurus have argued this, though some may.

That's EXACTLY what I said at the beginning of this thread. Follow the manufacturer's recommendations.

the thing that gets me , is most have stated that "excessive" rich running is damaging to the engine.. mind you I have OS, magnum and Supertigre manuals..while it's true that most suggest an initial running in with a rich setting , I did take note that it's not for very long and then they tell you to start leaning it so even under the gise of protecting their butts I can't see this as being "excessive"

Manufacturers directoins are primarly designed for people with almost ZERO technical knowlege and ability.

This results in directions being full of rediculous warnings like dont stick your finger in the prop etc. etc. So is it any suprise that the break in directions are written for the person they just told not to stick his hand the prop ? Their mindset is to not have guys leaning the engine on beak in, because many people will lean the new engine until the engine is really lean and ruin the engine, and there is the warrenty return [:@] In the end, the break in insturctions are written OVERYLY CONSERVITIVE for those that dont know anything and to keep them from doing something really stupid like leaning the engine to much.

The manufacturers directions are NOT written for the best performance, they are written so that operators wont ruin the engine on the first run. When you look at the manufacturers motiviation and what they are trying to accomplish in writing the break in directions, its easy to see why thier advice might not be the best for all of us.

JettPilot