how many tanks to run in?

[Delarado]

Guys,

flying an Os105 and the manual doesnt really say how many tanks to run in. Only specifies a "very short" running in procedure, and then just goes on to engine tuning.

Ive put two tanks through it now, one with the stock needle settings and another with the high leaned out 2 clicks.

When should I start doing full power climbouts and properly trying to tune the fuel settings?

Cheers

[jimmyhorns]

For ringed engines, the run in period seems to vary from manufacturer to manufacturer, and model to model, and doesnt seem to follow any sensible course.

If I was running a ringed in on the bench rather than in a heli, my method puts about 5 tanks through before the engine is ready to do any 'hard work'.

Id stay at stock settings for 5 tanks, and then start tuning from there, but I certainly wouldnt be putting any high load climbouts until id put those 5 tanks through.

Unhelpfully, the running in instructions are usually based around fixed wing prop engines, and bare little resemblance to heli life. Thats why I run mine in on the bench first.

[Delarado]

It actually states that it can be run in in the model, then goes on to talk about how to tune the hover and climb outs... So its def for a heli.

https://rcjapan.net/PDFS/OS105HZ.pdf

Page 28 ish.

It just doesnt state how long you should run it in for at stock settings before doing this!

[Raving Jim]

5 tanks at standard settings then start leaning the top end needle in tank after tank , after 10 tanks tune the mid an then u can hammer it .

[trillian]

There was a post by Curtis Youngblood some time back about running-in generally and it made good sense. I'll try to find it in a minute. What he was basically saying is he runs in starting to move towards the correct mix fairly soon but just not pushing the engine hard, so in essence not running super rich for too long, the idea being that you want the ring and liner to bed in and supposedly this won't happen as well if the run-in is all slobbering rich.

Having said that I would think the manufacturer would make sensible reccomedations for their engines.

[Delarado]

It doesnt have any recommendations thats just it! Just says "run rich for the first few tanks" basically.

Ive put 1 tank at stock settings now, 3 tanks and 3 clicks under stock on the high needle and 1 tank at 6 clicks under stock on the high needle.

Ill start leaning a few clicks a tank now i guess and go from there!

[trillian]

It doesnt have any recommendations thats just it! Just says "run rich for the first few tanks" basically.

Ive put 1 tank at stock settings now, 3 tanks and 3 clicks under stock on the high needle and 1 tank at 6 clicks under stock on the high needle.

Ill start leaning a few clicks a tank now i guess and go from there!

Well there used to be an 'ask Curtis' page online and now I cannot find it. This is from Ron Lund quoting Curtis via RR and is a few years old. The basic principle that was better explained in his Q & A column was that he was saying the main idea is slowly getting the engine up to proper operating temperature via the mix, starting rich but not staying super rich the whole time (obviously never letting it go lean) and during this time not pushing the engine, staying below full throttle or any high load moves until it's all bedded in.

This is from RR omitting the first bit which was rambling about engine starting and all the normal precautions;

"Once you have the engine running and tuned for a rich mixture, especially the idle. Hover it for about 30 seconds and set it down. Let it idle for about 20 seconds and cool off. Repeat this, adding 30 seconds to each hover until the first tank is gone. Don't run the tank dry. The idea here is to heat it up and cool it down, which is a very important part of break-in. If at any time the engine starts to go lean, shut it down immediately and find out why. Refuel and now follow these three rules for the next 15 tanks of fuel. It's ok to fly around, even do small loops and rolls. No high power maneuvers...period. Just follow the rules.
1. Don't overload the engine. No full throttle...period.
2. Don't over speed the engine. If you can't descend without over speeding, auto it in, or don't go high to begin with.
3. Don't run it lean That's it. You'll notice the engine making more power toward about the tenth tank. Don't be tempted to overload it until you've finished the break-in. Keep the fuel clean. Keep dirt out of the engine and you'll have a long lasting powerful engine. "

[Delarado]

sweet, well I did none of that. I just filled it up with fuel and hovered it about for 12 minutes, trying my best to keep load off but periodically changing head speed slightly (moving between normal mode, IU1 @ 1800RPM and IU2 @ 1900 rpm)

It is super super rich at the moment though. If you pinch the fuel line it runs for a good 10 seconds before shutting off.

Thanks for the tips, ill bear it all in mind. 15 tanks of landing every minute or two though? Seems boooooring!

[trillian]

Thanks for the tips, ill bear it all in mind. 15 tanks of landing every minute or two though? Seems boooooring!

Yeah, that does seem a bit tedious. I'm curious now as to what happened to Curtis's Q & A so if I find something more on that I'll post a link. There are also many variables such as the oil / nitro content of the fuel, the outside temperature, how efficient the fan on the heli is etc.

[Delarado]

is there an easy way to tell if its running too hot (I guess lean?)

Or is it just a case of listening to it?

Im guessing:

Rich: Loads of smoke. Bogging. Gurgling
Lean: No noticeable smoke. Bogging or completely cutting but without gurgling.

[jimmyhorns]

It is boring, but an essential safety net.

Im more used to running in nitro engines for plank use, which is why I find the bench running in method much more straightforward.

Irvine actually recommend that rather then running in with it in the model.

To 'ideally' run in a ringed nitro engine, you need to gradually increase the load and heat on the engine, so that the ring and the liner bed in properly.

As Swisstony would say, running in an engine is a lot like making love to a beautiful woman. If you arnt persuasive enough you never get to the bedroom, and if you are too pushy you get a slap round the face and told to '**** off'.

Never getting to the bedroom means not acheiving anything with your running in process as the engine and ring never get hot enough through friction.

Being told to '**** off' means having your engine seize on you, or the ring or piston break by getting it too hot too quickly, basically skiping foreplay.

The problem is that this is relatively difficult to do in a heli. Just to hover you are going to load up the engine by at least 50% if not more, which instantly is putting a fair amount of strain on the engine. Next is the fact that you cant be very close to the heli with it spooled up, so you cant feel how 'wet' the exhaust is with oil, only how much smoke it is making, which is a pretty crude way. Relying on the engine note isnt easy to do either if you are running in the engine, as until run in, you dont really know what it should be sounding like.

If you run in your engine on a bench, with a low load prop for the engine size, this allows you to: Moderate the load on the engine, moderate the speed on the engine, check the exhaust 'wetness' and completely concentrate on the engine, not on hovering the heli.

5 tanks on the bench is going to take you a couple of hours with cool down periods, and is pretty much stress free if you have ear defenders, your wife is out and your baby is elsewhere