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Old 10-11-2005, 08:13 AM   #31
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Originally Posted by qwerty
i suspected dirt in your engine, and when u said you were running on a wet track ... u need a rain cover for your air filter when running on a wet track. oh and i can see rust on the bearing

Its not rust.. i'm pretty sure about that. He has taken pictures of the engine without cleaning it ... so what you see there is particles of my broken engine.


But the engine is now at my friends place ... so he has to confirm this
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Old 10-11-2005, 08:47 AM   #32
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There are a few spots of rust here and there but most of the brown goo is baked-on oil from the fuel. You can scrape it off with a finger nail...
This engine's insides have never really been cleaned the past year, just a few drops of after run occasionally.
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Old 10-12-2005, 11:21 AM   #33
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Sorry about the engine...........of course, like we always say "Shit happened.."

Anyhow, those are some nice pictures.......and I can say it, the macro feature on typical digital camera like my Cannon S40 are VERY VERY DIFFICULT to take zoomed in pictures like that unless I have my camera mounted onto a stand and using a remote shutter and take the pictures...any little movement on the camera will not be focus...

My expereince is...probably 1 out of 10 pics I took are acceptabe with that close to the object, the other way to do is take a regular picture with the highest resolution and use photoshop to chop the part that you want and enlarge it......still, won't be as cleaer and nice like those.
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Old 10-12-2005, 12:55 PM   #34
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The cause could be one of many things. #1 you stated that you just put in a new rod...maybe one of the clips let go? Also what nitro percentage were you running? If you were running 30% maybe there was pre-detonation and small debris damaged the bearing (wrong head clearance) ?

For a bearing to break like there must be more too it. If you don't regularly clean the internals you run the risk of debris damaging the bearing and causing what you see.

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Old 10-12-2005, 03:48 PM   #35
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Originally Posted by jrabbito
The cause could be one of many things. #1 you stated that you just put in a new rod...maybe one of the clips let go? Also what nitro percentage were you running? If you were running 30% maybe there was pre-detonation and small debris damaged the bearing (wrong head clearance) ?

For a bearing to break like there must be more too it. If you don't regularly clean the internals you run the risk of debris damaging the bearing and causing what you see.

john
1/10 class in the netherlands run at 16% which also is the legal amount for races in the netherlands, no the clips are still in place.
Yes i understand now it might be debris or just bad luck, or just an manufacturing error in the bearing. there was someone on our local forum who said that he knew 4 ppl with a maxpower engine with the same problem.
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Old 10-12-2005, 04:32 PM   #36
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The problem wouldnt be a Max Power problem as they use Novarossi parts. I would guess that debris is the cause is everything else was OK.

The other problem I am seeing is that people are not maintaining their tuned engined properly. Ther rev more and create more power. This means more maintenance.

I would replace beaings once a season if its used often.
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Old 10-12-2005, 05:43 PM   #37
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Quote:
Originally Posted by lobotm
Its not rust.. i'm pretty sure about that. He has taken pictures of the engine without cleaning it ... so what you see there is particles of my broken engine.


But the engine is now at my friends place ... so he has to confirm this

i can see rust on the bearing cage. if rust is there then there would definitly been rust on the balls, when they spin at 30k rpm, they wear out prematurely and when loose enough they will vibrate and then explode like yours
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Old 10-13-2005, 08:05 AM   #38
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Quote:
Originally Posted by qwerty
i can see rust on the bearing cage. if rust is there then there would definitly been rust on the balls, when they spin at 30k rpm, they wear out prematurely and when loose enough they will vibrate and then explode like yours

LOL 30K this engine runs factory default >30k

MX 12 312
Technical details

Capacity 2,1 cc
Power 1,46 HP
R.P.M. 40,500 g/min.
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Old 10-13-2005, 08:15 AM   #39
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But you know manufacturers always exaggerate a bit.
Still, it was rather fast and it didn't treat the poor bearing balls gently .

And regardless whether it was a manufacturing error, wear, or something else entirely, I can imagine a weak bearing ball can split. Upon studying your bearing, you can see that the shinyness on the ball is only on the outside. Inside it seems to be made of a more porous material...
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Old 11-01-2005, 01:46 PM   #40
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A friend of mine had an identical failure in an almost new OPS about twelve years ago (I've still got the bearing somewhere) felt at that time and I still believe that it was a metallurgical issue in the ball and there was nothing we could have done (within reason) to prevent the failure.
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Old 11-02-2005, 01:08 AM   #41
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When I raced boats ball splitting and wrist pin dropping was a rampant problem.
This is why it occurred so often on boats. In rough water the prop can and does leave the water causing a 3000 to 5000 rpm rise and fall almost instantaneously. ( a boat can rack up thousands of these occurances in a very short period) this in turn causes what is called stop start skidding of the balls (the crank and inner bearing race accelerate and decelerate faster than the balls can) against the races causing micro flat spots. the ball fatigues at the flat spot causing it to fracture. (all hail the ceramic ball = no more problem) now all they have to worry about is race brinelling (race fatigue causing the ball grooves to get rough) but its better than a toast motor.

It is extremly rare for it to occur on a car engine as the only rpm jump occurs when the car shifts. the reason it occurs rarely on car engines because it takes many many rpm jumps for the ball to fatigue and split. were talking thousands of times and car engines never see this kind of abuse. Also the bearing sizes have increased which greatly reduces the chances of this.

Back when, our picco 21 marine engines had big end bearings the size we currently use in 12 motors.

Chances are you just ended up whith a bum bearing. Rust will cause the ball to react that way to.
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Old 11-02-2005, 01:15 AM   #42
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TIP:
If you ever have a motor disentegrate its super important to flush the heck out of the tuned pipe with the fuel. If you don't whats still in there can be blown back into the replacement engine when you start it up the first time.
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Old 11-02-2005, 06:38 AM   #43
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Quote:
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TIP:
If you ever have a motor disentegrate its super important to flush the heck out of the tuned pipe with the fuel. If you don't whats still in there can be blown back into the replacement engine when you start it up the first time.

I will keep that in mind
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Old 11-02-2005, 07:33 AM   #44
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I don't know if already mentioned, but maybe you are running a poor quality of fuel (or fuel that is too old) which is hurt the bearing.
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Old 11-02-2005, 05:25 PM   #45
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I don't know if already mentioned, but maybe you are running a poor quality of fuel (or fuel that is too old) which is hurt the bearing.

Normally my fuel can 2,5 litre wouldnt last longer than a month. I always run tornado 16% like most drivers do in the netherlands..

Well my friend and i always use tornado 16% and it normally doesnt give any problems.
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