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Engines Plugs Mufflers Fuel > New OS .50 sized motor ?
 
 
Big Pockets
Senior Heliman
Location: Pasadena, MD

I there any rummors about OS making a new .50 size motor like say a os .57?
05-02-2008 12:51 AM
 
 
BarracudaHockey
rrMaster
Location: Orange Park FL

They have had a 55 out in an aircraft version for a while but I've not heard any talk about making a heli motor out of it.


AMA 77227
http://www.jaxrc.com
05-02-2008 01:10 AM
 
 
PilotCK
Senior Heliman
Location: Maple Valley, WA

I am waiting till they do

Fly Hard, Crash Hard
05-02-2008 04:29 AM
HOMEPAGE  
 
 
dkshema
rrProfessor
Location: Cedar Rapids, IA

The rumors have been around for a long time. I believe the people that keep propagating the rumors are operating more on wishful thinking than on reality.

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* Making the World a Better Place -- One Helicopter at a time! *

Dave
05-02-2008 04:40 AM
 
 
Alican
Senior Heliman
Location: Hamburg, Germany

Well it would be funny if 200 people out of this forum write OS to do an bigger 50 size engine...
05-02-2008 07:54 AM
 
 
dkshema
rrProfessor
Location: Cedar Rapids, IA

Just what we need, another bored out motor having too small a rear-bearing to take the load, day in and day out.

After all, the point would be to get a larger displacement motor with the same mounting dimensions as the existing 50...which is already a bored out 46. That's going to require that the bottom end of the crankcase have the same dimensions as the current crop of 50's.

If you take a look at the current OS offerings, there no longer are any 60 motors listed. The demand for 60 sized motors dried up with the big block 90 conversions of 60-powered helis, and the 50-sized crop is just a bit small for plugging in a larger motor. There's also a point where plugging in a bored out 50 will most likely result in the need to change gearing, something the majority of 50 sized helis don't offer.

As for 200 people writing OS asking for a bigger 50, that's not a very large population to make a manufacturer spend the money to tool up to build a completely new engine. I'm sure it would be noticed, but then at the same time, it would tell OS that the market for a bored out 50 isn't there (just as the market for 60's is no longer viable).

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* Making the World a Better Place -- One Helicopter at a time! *

Dave
05-02-2008 01:17 PM
 
 
the Wasp
rrProfessor
Location: Vt

""which is already a bored out 46""

well actually the 50 and 46 use the same ring, it's the stroke that is diff,,

and I don't believe the bearing is to small,, I have here a Hyper 50 rear baring I just removed last week, it has only had 3 gallons run on it and it's tolerance is a bit loose, this tells me the bearing it's-self is the problem, I think OS got a run of 2nd-rate bearings,,

as I have been told by some one in the manufacturing business,, these bearing manufactures make only a given amount of bearing in a given size, if they run-out of stock they then buy more stock from other manufactures, this way they don't have to retool till their scheduled run,,, so if they buy from other manufactures they may be getting 2nd-rate stock,,

but then again this may be wrong LOL

Jim
the wife wont let me get a Monkey !!,,, damm, can't have anything
05-02-2008 08:43 PM
 
 
dkshema
rrProfessor
Location: Cedar Rapids, IA

Quote 
I think OS got a run of 2nd-rate bearings,,

The rear bearing has been a bone of contention ever since the original 50 SX-H was introduced. Do you believe after all these years, and all the motors that have been produced since, that "a run of second rate bearings" is still the problem? Are second rate bearings the problem when even third party bearings from multiple manufacturers ALL fail in the same manner? Even the ceramic ball/stainless steel raced after market bearings fail in the same manner.

-----

OK the stroke is a bit longer and the 50 wasn't a "bored out" 46...but still, the 50 is based on the 46 design. I was too glib using the "bored out" phrase. Next time I'll be certain to pay more attention to that detail.

-----

So the only two choices to make a "larger 50" is to either increase the bore, or once again stretch the stroke. If you want an even longer stroke, the crank diameter is going to have to increase. The bottom end of the crankcase is going to have to grow somewhat. And for that to happen, you're not going to be able to maintain the current bolt pattern, and you'll make a motor that no longer fits any current 50 helis.

Further, over the years, OS has gone back and forth between long stroke motors and motors having larger pistons. One of the last times they went the long stroke route on their larger motors was in the late 1980s. These motors were not overly successful and many users complained of high vibration levels. OS dropped back to more "square" motors whose stroke and diameter were closer to being the same.

If they go up much in piston diameter, they're again going to run into fit problems with the current crop of 50 helis. If they try to maintain the current engine outline, then the cylinder walls are where they will have to lose metal to grow the piston. I don't see that happening with great success.

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The quest for a more powerful 50 is nothing more than people now wanting to put the no longer available 60-sized motors into their 50 sized helis.


Perhaps OS and others ought to just quit making 50s and start making 60's again....

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* Making the World a Better Place -- One Helicopter at a time! *

Dave
05-03-2008 05:31 AM
 
 
BarracudaHockey
rrMaster
Location: Orange Park FL

The YS has the same bearing and I've seen them go too.


AMA 77227
http://www.jaxrc.com
05-03-2008 12:03 PM
 
 
dkshema
rrProfessor
Location: Cedar Rapids, IA

Quote 
The YS has the same bearing and I've seen them go too.

Wouldn't you know it, they got some of those darn 2nd rate bearings, too!

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* Making the World a Better Place -- One Helicopter at a time! *

Dave
05-03-2008 04:52 PM
 
 
lightningrc
Key Veteran
Location: UK

Got a bad OS 50 hyper rear bearing in my hand now , my engine has only done afew gallons and well looked after , the liner is as new and piston only a couple of light scores.

The noise is the air was really bad , but would have never of betted any money that it would have failed before I striped it down , im glad its failed as atleast I know ive found the fault.

Just put it aside a hyper 90 rear bearing and yes it is very small.

Think OS should redesign these engines and fit bigger rear bearings instead of us lot footing the bill.

Also as well noticed theres no numbers on my rear bearing alot of cheap bearings are unmarked.
05-03-2008 06:02 PM
HOMEPAGE  
 
 
PilotDaz
Senior Heliman
Location: Seattle, WA

Quote 
Got a bad OS 50 hyper rear bearing in my hand now , my engine has only done afew gallons and well looked after

Yep, been there plenty of times! I go through engine bearings like I do underwear!

~There are two kinds of heli pilots: those that have crashed, and those who are about to.
05-03-2008 06:23 PM
 
 
the Wasp
rrProfessor
Location: Vt

""Wouldn't you know it, they got some of those darn 2nd rate bearings, too!""

hey dkshema don't mock me, those bearings are high speed bearings and are rated some 10,000 RPMs more than most of us spin them, they should hold up but they don't,,

I'm starting to wonder if your are right and the rear bearing is just to small for the engine, my friend is a heli pattern pilot and he runs a head speed of only 1650 on his Evo 50 and Sylphide 50 and he has many many gallons run threw his Hyper 50s with no bearing problems,,

with a gear ratio of 8.73 a head speed of 1650 should give a engine RPM around 1400, and I know 1 of his engines has like 30 gallons run threw it and the other has like 20 gallons run threw it and they never been apart, at those RPMs it's no wonder they hold up !!

Jim
the wife wont let me get a Monkey !!,,, damm, can't have anything
05-03-2008 08:41 PM
 
 
dkshema
rrProfessor
Location: Cedar Rapids, IA

High speed is one thing. The bearings should be able to handle the RPM in stride.

It's the repeated pounding the rear bearing takes from each and every power stroke. That's a load they are not designed to take. There's very little surface area available in one of these ball bearings to absorb the shock. If you keep a collection of dead bearings, you'll see that they fail the same way, with the wear pattern being the same. I've often wondered how a bearing that uses needle type rollers instead of balls would hold up in the same situation. There would be more surface area to spread the load.

-----

My OS 70 finally ate a rear bearing, but it took it four years to do so. My OS 50's generally chew up a set of bearings a year. So far, I've not had any complaints from the OS 37's I've been running, or the YS 50 that I've flown for two years.

-----

These are some shots of my dead OS 70 bearing after I replaced it.

The inner and outer races look as if someone had taken a miniature jack hammer to them.



-----

* Making the World a Better Place -- One Helicopter at a time! *

Dave
05-03-2008 09:04 PM
 
 
RappyTappy
Elite Veteran
Location: Las Vegas, NV

Man, I can't wait till OS pumps it up to a .61 size, oh, wait, they already had a .61 SX WC, lol.

IMO, What helps eat these bearings are guys running 2000-2100 headspeed which just revs the living daylights out of the bearing, at 8.5 ratio pushing over 17500 near 18000 rpms. Like Wasp said, a engine with more modest headspeed that like which used to be the norm only a few years ago (1800rpm) bearings last a lot longer. A crazy high headspeed combined with guys doing the crack stick on a cackling lean engine will do it too. I had 20 gallons of fuel on a OS 50 SX-H years ago when I ran a 1800 headspeed on a Evo 50, bearing was as smooth as from the box when I sold it.

Yea, i can definitely see that happening too dkshema, thanks for the pics, can definitely see some bearing taking abuse in there!

Chris

Logo 500 3D

Forever Brothers
Mickey Tylo
05-03-2008 09:22 PM
HOMEPAGE  
 
 
lightningrc
Key Veteran
Location: UK

dkshema
mine looks exactly the same , you can see the heavy pitting with having to split it .
05-03-2008 09:22 PM
HOMEPAGE  
 
 
PilotDaz
Senior Heliman
Location: Seattle, WA

Quote 
IMO, What helps eat these bearings are guys running 2000-2100 headspeed which just revs the living daylights out of the bearing

That was my theory too, but I installed a new engine a couple of months ago and religiously ran it for 85 flights at a 1950 RPM headspeed. Also made sure to keep it nice and rich. End result? Bearings went south after 85 flights.

Seems like there's no avoiding it, regardless of how you care for your engine.

~There are two kinds of heli pilots: those that have crashed, and those who are about to.
05-04-2008 12:39 AM
 
 
SkateFreak
Key Veteran
Location: Cambs UK/Luton

I find this really strange because I have a hyper here that is bone stock asside the piston that I had to replace after breaking it myself (with a toothbrush through the backplate opening) and after 3 years of service the ring finally gave in but the bearing is still swish...

What is everyone doing to thoes engines heh.

Admittedly though its only been run around 1800-1900'ish mark until recently...

maybe I got a 1st hand bearing heh

-Jvr
05-04-2008 11:29 PM
 
 
westcoastchoper
Senior Heliman
Location: Denton, Tx

I bought an os 50 sx for my plane when it first came out and the bearing was bad b4 I ever started it. Completely rusted and DRY. Boca bearings are cheap and last a lot longer. I never had a problem with my Hyper 50, but I opened it up and checked the bearings b4 ever starting it.
05-05-2008 02:46 AM
 
 
cyclic fever
Senior Heliman
Location: Seymour Indiana

Quote 
That was my theory too, but I installed a new engine a couple of months ago and religiously ran it for 85 flights at a 1950 RPM headspeed. Also made sure to keep it nice and rich. End result? Bearings went south after 85 flights.

Thats good life from the bearing. 1950 is still a good deal higher than the 1800 that was talked about before. It all boils down to the more performance you want, the lower the TBO will be and you had better know how to use what you bought to get the most life out'a it.

You buy a new Viper and club race it in So-Cal and your tearing it down a rebuilding all the time. Same car kept in the driveway and used as a daily driver and you'll change oil and thats about it.

OS knows motors and they built it for those people that know what they are buying and what their buying it for. The people that bought it, ran it for all that its worth and complain the motor didnt last long are just clueless. If you cant swallow the high freq. of rebuilds to get that performance then back it down or go .30 class where your funds will go farther. If someone whats to run the big boy motors they should have a big boy attitude about it too.
05-05-2008 08:42 AM
 
 
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Engines Plugs Mufflers Fuel > New OS .50 sized motor ?
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