OS .50 RINGED
 

I AM LOOKING AT PURCHASING AN O. S. 50 SX RINGED ENGINE AND WOULD LIKE SOME INPUT ON WHETHER TIS IS A GOOD ENGINE

RE: OS .50 RINGED
 

Hi,

I have one of these engines, and i must say that they are extremely powerful, However if you are planning to mount this engine inverted , my advise is chose something else. This engine is a pain to set inverted, You will spend the most part setting the engine right and she will quit on you 4-5 minutes into flight. The tank height is a big issue on this engine. My advise would be to go for the .46 AX , this is a much better engine and extremely powerful , with practically no running issues.

Regards
Ravi Kothari.
Bombay India.

RE: OS .50 RINGED
 

I don't own one. That said I read alot of posts of early bearing failure and liner and piston problems.

RE: OS .50 RINGED
 

I have one that I have been running on the plane I fly most of the time for about a year. It provides plenty of thrust to handle a 4 lb 3d plane , starts easily and never stops in flight. I have had no bearing problems. I had a 46 FX on the same plane for a while and the 50 is considedrably stronger. I like mine.

RE: OS .50 RINGED
 

ΗI.
I don't have own for myself but i've seen 3 of them running in my field.
They are great performers out of the box.
After break-in they start without an electric starter on second flip.
No problems when tuned good,which is very easy.
Don't think much about it.
You will hear problems with every glow engine...
But i think that there not BAD engines,just BAD UNEXPERIENCED HANDS!
Enjoy
Kostas

RE: OS .50 RINGED
 

Go buy a Super Tigre .51, same displacement and lot less worries.

RE: OS .50 RINGED
 

There is a guy at the field that has two of them. I had to work on the engines.

The rear bearing has a plastic type cage and this fails after 4 or 5 gallons of fuel. The plastic doesn't seem to hurt anything but the ring? I had to put new Bowman rings in them also.

They ran great.

Enjoy,

Jim

RE: OS .50 RINGED
 

I have a .50SX in this 4 Star 40. It's a good engine.

RE: OS .50 RINGED
 

You might also look at the Enya 50SS ringed engine. It is a few ounces lighter and about $30 cheaper than the 50SX. It is available mail order from MRC for $120 including shipping.

RE: OS .50 RINGED
 

Ι think that you're not correct.
Usually ST engines are not good performers out of the box and also they need special tuning treatments.
Also take a look at the price!
OS 50 SX costs 159.99$ to 169.99$.
ST is way too low.
And this has to do with performance and reliability!

RE: OS .50 RINGED
 

Kostas, I hate to do this, but the time has come -- read the longevity test in post 23 of this thread.

http://www.rcuniverse.com/forum/m_34..._1/key_/tm.htm

RE: OS .50 RINGED
 

Kostas, read the whole thread, then draw your own conclusions.

RE: OS .50 RINGED
 

As per DR NITRO OS50 could not get past 10 gallons without puking bearings. This is 2 different engines. I don't know about you but I wouldn't spend $160 for a 9 gallon engine when a ST 51 at about $80 made it to 100 gallon club.

RE: OS .50 RINGED
 

umm... where do you think you're going to buy an italian super tiger from... the st in post 23 is the italian version.... he didn't talk about the newer china versions???? I have a st g90 china version. not bad but they are cheap for a reason.

I have a 50sx... I like it... I've ran the he** out of it last summer and never a problem.

RE: OS .50 RINGED
 

Keith You know, I'll bet ya that engine will run great till 2 seconds before it's demize. Tons of people have found out the china engines are great and parts interchange perfectly. I have both and I'm pleased. You can still get NIB italian ST's all day long on E B** and the classifies here. Start reading up on modern OS 50 and you'll hear of lots of longevity problems. :D:D:D

RE: OS .50 RINGED
 

I bet that you don't know what you are saying about OS 50 SX.
I have three of them in my club.
NO PROBLEM AT ALL.
Proof us that you have a problem with 50 SX.
And i'll proof that you don't know how to tune an engine.
Can give more brain to have a little respect in a manufacturer with years and years of manufacturing....

RE: OS .50 RINGED
 

Speedster you know, I'll bet ya every manufacture has bad ones from time to time and for every bad os i'm sure you can find a bad st or any other brand... I'm not trying to defend or say that i'm a huge os owner etc... out of 10 engines that I own only two are os. Another brand that I own is also made in china and plain and simply the china engines are not made on as tight of tolerances and it is indeed a "coin toss" as to whether or not you get a "good one".

I'm gonna stop here... I could go on and on.... I like chevy you like ford they like dodge... whatever... run what you like and have fun.

Like I said... I like my os and I've ran the heck out of it. It hasn't given me a reason to dislike it.

RE: OS .50 RINGED
 

can some one tell me if the os50 can run 12x5 apc with 30% nitro?

RE: OS .50 RINGED
 

Lee,


The OS.50SX can run with up to 15% nitro, as you can see in [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXALM2&P=RF]this Tower Hobbies page[/link]. Using 30% nitro would require two extra head shims (or a thicker one), to reduce the compression ratio.

As to prop sizes, look into [link=http://www.os-engines.co.jp/english/line_up/propelle/proindex.htm]this OS web page[/link].

The 12x5 seems to be on the small end, but it offers more load than the recommended 11x6.

RE: OS .50 RINGED
 

OK Kostas -- here it is --

http://www.rcuniverse.com/forum/m_3817631/tm.htm

RE: OS .50 RINGED
 

???
Anyway....


Lee you definately don't need too much nitro.
OS engines are very happy with 5% and 10% nitro.

RE: OS .50 RINGED
 

I have done a fair bit of work on two SX 50s at our field. One's piped and the other is running a Tower muffler. They are both thrashed mercilessly - full throttle runs are the norm.

Let's deal with a few of the comments in this thread ...

Isn't it amazing how a thread talking about OS engines brings out all the n00bs who have had nothing to do with the engine in question. Speedster, don't read about them - go out and work with one then come back in here and add some value to the discussion, OK?

Jim, I'm not sure if they changed the bearing specs for different production runs in these engines but the SX 50s I've seen have had metal caged generic Japanese manufactured 6902 type bearings in them. What did you use as a replacement bearing in the ones you worked on?

I wouldn't recommend 30% nitro as a matter of course. I have seen the OS SX 50 scale up productively to about 20% nitro without any problems with detonation. 30% is probably a bit beyond the ideal diminishing returns curve but I have seen a piped SX 50 run without issues on a 30/18 mix. The SX 50s I've seen run happily enough on 5% but do run quite a bit stronger on 15%. An example I tested the other day (Tower muffler fitted) on an APC 12.25x3.75 prop did 12,400 on 5% and 13,200 on 15%. That's more of a scale up than your typical sport .46 engine. In summary, 15% seems to be the sweet spot for outright performance versus economy.

The head bolts were loose. So what was the point, Britbrat? Or did I miss some subtelty?

RE: OS .50 RINGED
 

It reminds me of when a monkey starts hooting at the zoo. Soon more join in hooting, shaking the bars and pooping in their hand and throwing it at the zoo visitors.

RE: OS .50 RINGED
 

LOL! Great analogy!

RE: OS .50 RINGED
 

Harry,


I have seen a few such engines here trash their bearings too.
People here use Omega and CoolPower 5% almost exclusively in these engines.

And the ring doesn't last over 10 gallons for anyone, more likely 5-8 gallons.
Here, it costs about $30 to replace...

This seems even stranger, since there are only a few such engines...

The price difference over the .46AX does not seem justifible to most people.

But they do behave nicely in 3-D planes, until they need major 'medical attention', that is...


Nitro... This issue is discussed yet again.

OS recommend no more than 15% nitro and the medium #8 glow-plug, for this engine to run properly.

If you use more nitro and/or the hot A3 glow-plug, you would have to richen the mixture considerably, so the ignition would be delayed enough to prevent detonation (known as a lean-run to most people), but then you may have a soggy mid-range...
And I am not even talking about the fuel bill that you would be paying.

The fact that nearly any engine can be made to run on more than the recommended maximum nitro, does not mean it is the right fuel for it.
It simply doesn't; not by a long shot.