Hi everybody

A flying mate gave me his engine for a bearing change....it was quite rough but the engine was running good and strong....anyway I disassembled the engine and look what I've found apart from rusty with lots of play bearings (he always used omega on this engine)....

He said engine is about one year old...sat for a while and then he brought it back into service, but he aske me always for help with his engines...

I disassembled, cleaned with a brass brush, and put it back together...compression is good but there is no pinch.... let´s see how it performs on sunday, as said before, the engine was running strong (about 13000 with mas 11x6 at about 2500m over sea level)

Too bad that this kind of things happen....and it is quite complicated to claim a warranty here because most of the engines that we get here is because we bring them from the usa, and shipping it from here costs very much. We have no O.S reps or something that would honor any warranty...

Saludos,
Jorge

Do you think OS would accept any warranty on this subject?

justengines in UK can help you

Jacques

How does the outside of the cylinder peel? It looks like corrosion.

The specs that I can see on the inside of the cylinder look like smeared brown bearing rust particles that were trapped between the cylinder wall and piston.

I think any engine will destroy itself if you don't take care of it......

Time to try a ASP XLS 46 cylinder piston set in the engine?

I feel sorry for your friend, can't imagine any form of engine abuse that would make a "proper" liner peel on the outside of the lower end.

So unless there is something particular about OS engine users (?) there is something not right with their ABN products....

now i gotta take mine apart....that sux


*edit nah mine is fine

Same feelings here.

If you look carefully, on the outside of the cylinder peeled spontaneously, there is no connection between the flakes that appeared outside...
The scratches inside I think are caused because of the peeled flakes on the outside.

The man is going to run it with the new bearings and as it is until it dies.


Jorge

The scarring on the inside of the cylinder bore is probably from the "Shrapnal" plating flaking off the ouside of the sleeve and being digested by the engine. It also could be the cause of the bearings to go south.

Is it just me or does the sleeve seem to have alot of blueing? Isn't blueing a sign of an overheated engine?

There's a lot of problems with that sleeve. It has significant spalling of the nickel on the outside of the sleeve in the passageway areas that has nothing to do with wear but perhaps more related to corrosion

No, that's pretty normal, all of the ABN (or ABL as O.S calls it) have this weird colors

Look [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXGCU6&P=ML]here[/link] at a new P+L set

In all of my engines, I see a slight blueing on the sleeves but nothing that comes close to the darkness of the blueing on this one. I have never seen ( at least on my engines) blueing on the inside of the sleeve. I have seen engines that were ran with to high of a nitro content or run to lean that have had blueing on the inside of the sleeve. I am not trying to slam your friend , but anytime there is rust inside a crankcase you have an engine that has been improperly cared for. If one does not know how to care for an engine , then they might not understand how to operate one properly either. Most of the time I see people blaming the engine for a failure, it is actually the way the motor was operated and cared for. These are just my observations and heck I could be wrong..

And they said ABL technology was supposed to have cured this... Yeah, right!

It seems even in light of carcinogenic waste products; and the resultant expensive waste management processes; the best replacement for true chromium electroplating, is more true chromium electroplating...
This is true, at least from where OS is looking at it...

This is much more rare with Thunder Tiger and Webra engines that also employ electroless nickel coating... And has anyone heard of a YS (with non-Nikasil coating) peeling its nickel?


Teymour,


It is not 'too much nitro' that can cause this to happen...


It is said that nearly all road accidents are eventually and ultimately caused by people who use the roads...
Yet, I am quite sure virtually no-one drives his/her vehicle, or crosses a road with the malice intent of causing an accident.

After all, accidents are accidental; even if a violation, or an error is involved... We are just humans and we do err sometimes.

But roads can be designed to be more tolerant to driving errors and to most violations; so committing such a wrongful act will 'fail' to cause an accident.


Using true chromium electroplating over brass, will; by all likelihood, prevent potential and wide-spread peeling of the sleeve's surface...
Even if a chromium 'islet' (and chromium electroplating is 'all islets'; like a dried lake bottom, when viewed through a microscope) is dislodged from the brass base metal, by a shard of bearing-cage 'shrapnel'; the bond-strength of the chromium to the brass, will make sure it is all that is dislodged...

If; on the other hand, the continuity of the electroless nickel coating surface is broken by a scratch, from a grain of sand; a good part of the nearby coating will be 'going south' quite rapidly; simply because it was never designed to survive such an event.

And no, the copper flash-coat of ABL, does not seem to solve this either...


...In my book, that amounts to 'an accident waiting to happen'.

Blaming the drivers and the pedestrians (and the engine users) is much less expensive; than actually solving the problem by superior design...


EDIT: Typo and elaborations.

I could not have said it any better myself.

Unfortunatly the world is not perfect and we have to do the best with what we have...

I was going to hang back on this one...
Was not going to get into another of these O.S. "peeling" issues...BUT...[:@]
I'm having a hard time holding back, because it reared it's ugly head AGAIN, just this last week w/ a friend of mine and his .55 AX...it did pretty much the same thing as the original posters engine...the nickel is comming off...

My friend ran the engine dry immediately after the last flight of the day..pulled the fuel line off while running, after the last flight...while the engine was still good and warm..then used after run oil (genuine Hobbico stuff! ) just before putting the airplane into his car to take it home...

There are several of us that have actual experience with the peeling/flaking, and have had conversations w/ the above individual...a certain "paranoia" about O.S. engines exists now, among quite a few of us...so he was warned you can say..but still it happens!

MotorMan (Iflyglow) might have a point...
Maybe it is corrosion that is causing the initial problem?
Perhaps the Nickel from the outside of the sleeve is getting down into the mix of the crankcase, then passing up throuh the ports, and into or inbetween the piston/sleeve?
That would still indicate a poor bonding job in the first place though, wouldn't it?
No excuses...

Apparently the engine with this linner is still running.... MVVS engines this size are not.

I think it's extremely unfortunate that the O.P. has had such a problem...

My friend is only 20 miles away from me, and has had the same problem, and could easily get parts...but it's the point of the matter..."IT" shouldn't still be happening!

A new piston/sleeve for a .55 AX is $89.00
My friend could easily afford that, BUT..

Has it quit running?

No...it hasn't exactly "quit"

How do you know?

Jorge just replaced the bearings and his friend is going to continue using the engine as is.

I'd venture to guess that it runs better with the new bearings.

B-W...This is not RC Groups...if you want to get into a pee-ing match, go mess with Konrad...

Some members will notice their messages either deleted or edited. It would be good to hear factual information about any make of engine having problems without people jumping on the bashing wagon, or taking shots at their favorite RCU targets.

I didn't lock this thread and I don't know who did, but it sure needed it.