OS91 keramisches Lager macht Geräusche

[ferry]

hallo leute
i have a motor here , with a full ceramic rear bearing .
is it normal that the motor makes more noise mit idling ? [sounds wie ein ducati kopplung :] .
in flight in the air it makes more noise then normal bearings , yet , the bearing looks good , and has no spiel .
meine frage is , ist das normal or should i change it ?
regards und grub ferry

[heliprofessor]

AW: OS91 keramisches Lager macht Geräusche

Bist Engländer oder Deutscher?? Selten so schlechtes deutsch gelesen.

Zum Lager: Sollte normal leise laufen.

[Uli_ESA]

AW: OS91 keramisches Lager macht Geräusche

Bist Engländer oder Deutscher?? Selten so schlechtes deutsch gelesen.

Hallo,
nein weder noch, er ist Hölländer, hat halt English und Deutsch kominiert. Wenn es die nicht passt besser nicht antworten wie so etwas.

@ Ferry, normally ist the bearing with out noises, I Think it has a defekt.
Regards
Uli

[mario_d]

AW: OS91 keramisches Lager macht Geräusche

hi there ..

so as i know .. normally a ceramic surface has a very small roll resistance, so it is applicable to use it in a context, where 2 or more items are in friction. next thing is, that ceramic surface is very hard but -as a result- also very brittle.

..because of this attributes, it is used e.g. in the dentistry .. to get a smooth contact behaviour between several teeth ...

as a dervation i would guess, that a ceramic bearing should be more quite than a normal bearing out of steel. so in your case, i would prefer to change the bearing.

good luck and byebye
mario

[ferry]

AW: OS91 keramisches Lager macht Geräusche

hi , thanks for answering guys .
yes im dutch and my english is better then my german , sorry :]
the engine is gonna get a new bearing since it is not running good either [it was when i posted] .
it seems to me that there are different sorts of ceramic bearings out there , i myself had a ceramic from hl , and that runs quiet and good after 60 liter .
thanks guys , grub ferry

[DocMichi]

AW: OS91 keramisches Lager macht Geräusche

Hi Ferry,

Some time ago I had a chat with the Austrian general distributor of Yamada engines about different types of engine bearings, e.g. steel and ceramic.

He stated that most people do only consider inner/outer diameter of the bearing, when exchanging the original steel one... while the specs of the original bearing balls itself should also be considered, since they can be completely different compared to the ceramic bearing balls... which could eventually do harm to the engine, in case the bearing should develop too much play...

after this conversation I left the idea of exchanging the main crankshaft steel bearing with a ceramic one and decided to stick to the steel type bearing.... and to be honest: steel bearings are a lot cheaper and as a matter of fact you could buy at least 5 Yamada bearings for the price of one full ceramic bearing which in most cases will top the overall motor life time, I guess...

Best Regards,
Michael

[ferry]

AW: OS91 keramisches Lager macht Geräusche

yes michael , thats very true , a steel bearing is really cheap .
i think it is weird that when i was looking around on runryder for ceramic bearings that the americans dont like ceramic , i mean , runryder is the world biggest forum and i could not find anything positive about ceramic on there .
also , some people on there state that the cheaper [100 euro ] ceramic's are rubbish and unreliable for methanol engines , they claim the ceramics could implode becouse they are too brittle [like mario b said] .
they also claimed that a proper ceramic bearing special for motors will cost more towards 1000 euro[*]
on the other hand , i know at least 2 people who fly with a leuschy engine for many liters ohne probleme .
maybe i go for steal and buy afterun oil , i never used afterrun so maybe it helps .
regards ferry

[DocMichi]

AW: OS91 keramisches Lager macht Geräusche

Hi Ferry,

Don't get me wrong, I do not want to blame Mr. Leuschner (Leuschy) as someone who sells crap but it's worth mentioning that a lot of people still use and will use the original steel bearing and are really happy with them...

a) they're cheap
b) if treated properly they do have quite a long lifetime
c) they are being used in nitro engines for quite a long time now and seem to be the best deal between cost and effectiveness
d) they're cheap (as mentioned above) and are available as an original spare part from the distributor and as mentioned before you can buy a couple of steel bearing for the price of one full ceramic bearing

Some guys (such as Mr. Leuschner) are selling those ceramic bearings, which fit in into the engine very smooth and absolutely perfect - believing them...

BUT: e.g. Yamada does NOT sell ceramic bearings as an upgrade.... nor does OS for the 50 class engines...
=> those companies want to earn a lot of money... so if there were so many people keen on ceramic bearings and if they were the perfect deal, they would already sell it as an upgrade.... and all the world class flyers would use them and also Rüdiger Feil would offer them for his tuned 90 class engine...

I'm using nitro engines for quite a long time now (for my rc cars and my helicopters) but I've always used steel bearings when it came to the point of exchanging them... and I did use the original bearings, since I can be sure that they drop in without any problems...

As mentioned by the Yamada Austria distributor:
A bearing that has the same inner/outer diameter as the original steel bearing may fit in but this does NOT mean, that it's the right or perfect choice for the engine since there are other specs which should be considered...

And to be honest:

I do know many people who have burned dozens of gallons of fuel with their helicopters and had no problems, although they had not bought those ceramic bearings...

Maybe you should give Rapicon fuel a try.... I'm using it for quite a couple of gallons now and I'm very, very happy with this choice...
I do not add any afterrun oil... that's not necessary any more since Rapicon does prevent from rust the best way you can imagine... and I've never had problems with the bearings since using Rapicon!

Best Regards,
Michael