Nitro Noob Engine Break In Advice Please

[hb1201]

Hi again everyone! I have a question regarding proper engine break in.
I have an OS 50 SX-H Hyper in my Trex 600N, but being new to nitro, and having only flown small electrics, I am not comfortable trying to learn & break in an engine at the same time.
I know from reading post's you can do it on a bench, but it must be under load. Some say no to that?
So....help please?!
Thank you again!

[DCflyer]

You can run a tank or two through it with the blades off on the ground to get your idle point and idle screw set. After that its time to get airborn.

For break in, just follow the engine directions - OS's usually like two full turns out on the high and low needle but the OS50 only has one needle I believe. You will also want to depitch your helicopter for a few tanks so it doesn't overload the motor. 9-10 degrees pitch is good for this. After a few tanks you can up the pitch to 12+ degrees and begin to fine tune the needle.

[hb1201]

Thanks for the reply!
So you"Don't" need to have the engine under load? "Blades Off"
I know the reason of course, but every where I have read said it needed to be under load?

[ticedoff8]

First and foremost: Do not break in the engine on a stand or with the blades off. That's not what he said.

And, being new to nitro and testing with blades off could result in disaster!
Yes - if you are ultra careful and do NOT try to spin the head too fast, this is "safe".
But not for break in, only for setting the basic needles for idle and to confirm the engine will start.

But, as a "newby" to nitro, it would be really easy to accidentally spin the engine into revs that are high enough to A) Destroy the engine or B) Break something on the heli and hurt yourself.
And, if the TR gyro hasn't been confirmed, you could easily get the heli pirouetting on the ground.

If you have an engine stand, then YES - do the first run ups on the stand with a prop as the load. On the .50 size, I would look at a 10/6 or a 10/8. Check the OS Engines web site for their fixed wing .50 sizes and see what prop is recommended and use that.

But - you are not trying to break in the engine on the stand - just get the basic needle setting for idle and then confirm the overall health of the engine.

If you follow the OS Engines guide for that engine, it states very clearly what is recommended as the "starting" point for the needles. If you understand what the guide is telling you, you should not burn the motor up in your first few flights.
If you leave the needles at the factory recommendations, it will be rich but flyable.
For your first 5 or 10 flights, just go up and hover and do gentle circuits and climbs. But, you have to "heat cycle" the engine, so once or twice per flight, do a full collective climb followed by more gentle maneuvers.

I also recommend a governor for your engine. The GOV will make setting the head speed a very, very simple process. Using "throttle curves" is difficult and error prone, even for a veteran of nitro helis.

[hb1201]

WOW! Thank you very much for explaining that so a dummy understands!
I got it...I really appreciate the help. I need all I can get!

[DanMcN]

hb1201

I recommend a multigov and backplate sensor, it works great. At the risk of being new and tearing up a 300$ engine and maybe the heli. To break in a engine, the engine has to get up to the cool/rich side of normal operating temp. With the engine installed make sure your throttle moves to its high and idle cut off limit. Set up a transmitter idle cut off. Two turns as the manual says is way too rich, at1.5 turns is a good place to start. With main blades off set your idle and idle cutoff. Bring the rpm only high enough to spin the head then look and listen for anything unusual. Right after engine shut down feel the engine backplate it should be cool to the touch. Hover the heli a couple of tanks then start leaning it out. Right after landing some people temp gun and should be 185+- or I feel the backplate, it should be hot but I can keep my finger on the backplate. Once you get so time flying a nitro you can hear how its running.

Replace the main engine bearing. The OS back main bearing is crap, it will corrode then destroy your engine. Go to rcbearing.com and buy a couple stainless steel not the stainless ceramic ball bearings. The front bearing lasts but I'd buy a spare.

Good Luck

[hb1201]

Thanks to you also for the great advice! I didn't realize what a pain these things are. It's like every day I have to order more parts, and it hasn't even spooled up yet!

[dchekas]

I wouldn't immediately replace the rear bearing necessarily.

Inspect the rear bearing by removing the backplate, and see if it has a steel cage or a plastic cage.

http://www3.towerhobbies.com/cgi-bin...I=OSMG1955&P=Z

Tower has the old, now discontinued steel cage variety pictured, along with the newer plastic cage. (P/N's 25830000 and 25830010 respectfully).

If you have the steel cage, I agree, replace the bearing with a plastic caged version.

If you have the plastic cage, like the newer .55s include, then just run it.

[hb1201]

Thank you! I appreciate it.

[ticedoff8]

hb1201: Please, do NOT open up the engine and start changing parts!

That is a ridiculous suggestion to make to someone that is new to nitro engines.
The engine is fine just the way it is right now.

If the engine is new right out of the box, you can bet that the factory has the right parts for the job.
I am not an OS Engines fan - I run all YS because of some bad experiences I had with new out of the box OS engines in the past.
But, I've been running nitro for 40 years and I consider myself pretty handy. And an engine tear down and rebuild is a 30 min operation for me.
I am sure the guys that are recommending to tear your new engine apart and start poking around do not mean to give you bad advice - but it is bad advice.
Its like suggesting you open up that new $300 Scorpion Limited Edition so you can change the bearing before you fly it. Not a good idea.

Running a nitro engine is not rocket science. It is basic chemistry at most. It is the same as running a LiPo 12S for the first time. Or trying to figure out the right ESC.
Just like running eHelis, there are going to be add-ons that will make life easier.
But many may not be required right away.
Although, the gov would be something I'd get right off the bat.

[dchekas]

Originally Posted by ticedoff8

hb1201: Please, do NOT open up the engine and start changing parts!

That is a ridiculous suggestion to make to someone that is new to nitro engines.
The engine is fine just the way it is right now.

If the engine is new right out of the box, you can bet that the factory has the right parts for the job.
I am not an OS Engines fan - I run all YS because of some bad experiences I had with new out of the box OS engines in the past.
But, I've been running nitro for 40 years and I consider myself pretty handy. And an engine tear down and rebuild is a 30 min operation for me.
I am sure the guys that are recommending to tear your new engine apart and start poking around do not mean to give you bad advice - but it is bad advice.
Its like suggesting you open up that new $300 Scorpion Limited Edition so you can change the bearing before you fly it. Not a good idea.

Having seen several steel retainer style bearings lose a piece of the retainer and grenade the engine, I respectfully disagree.

Changing bearings is a very simple process, and a skill every nitro pilot needs to learn.

[ticedoff8]

You may not be seeing the bigger picture.
He is not a "skilled mechanic" - yet.
He has never opened a motor before in his life. This is his first (maybe last) effort to get into nitro.

To get the main bearing out, he has to strip then engine down to a bare crankcase with just the front & main bearings left in it. Everything has to be removed so he can heat the crankcase to get the bearing out.
You think he knows that?
That basically describes a learning process and knowledge that he does not have right now. It is about 10 steps that he has never, ever, imagined.

And, if he doesn't do it? Well, it is a "grenade". Love that term.
Why not just say "Yeah. Nitro. Big f**kin mistake".

At some point, yes, he will need to tear into the engine - but not when it is new out of the box!
It's an OS Engines motor. It may not work well for extreme 3D an smack, but we are not talking about that here. It will be fine.

When you put a roadblock like "Oh. The motor you just paid $300, it has a major flaw. To fix it, you have to preform a major tear down and replace a component using skills you never learned. Oh. And if you make a mistake, the engine is junk and you flushed $300 down the drain" he will never get into nitro - and I don't blame him.

I would say, while you are trying to be helpful, it may not be working.

[dchekas]

I'm not getting into a pissing match.

hb1201, check your PM.

[hb1201]

WOW! I just got a chance to read the above. Not sure what to say.....But it makes sense to me. 3D is out of the question for a long time for me. I will be happy if I just get everything hooked up correctly and get it running! lol
I am getting frustrated with nitro though so who knows......
Thanks for your advice!

[ktmdiesel]

Did you ever end up changing the bearings and getting the heli running? lol

[ktmdiesel]

My motor is from an older kit, I wonder if it would be in my best interest to replace these bearings. I know this post is old can anyone chime in on this?