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Post by amazombi on Apr 3, 2011 10:27:33 GMT
understanding women ?? im lost straight away, mad cunts indeed Sounds like the deepest possible understanding to me.
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Post by gioia on Apr 3, 2011 10:41:50 GMT
..Iam just chuckling away to myself here..reading back through this thread its like Monty Python, meets Chuck Norris in a chippie in Wigan... ;D
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Post by eean on Apr 3, 2011 12:54:33 GMT
..Iam just chuckling away to myself here..reading back through this thread its like Monty Python, meets Chuck Norris in a chippie in Wigan... ;D PMSL ;D ;D ;D Like I said earlier, thanks for the input, advice and theory of how to fit this bearing and at the end of the day even I did it my own way, so there is no one way to do it really, its just a matter of not damaging the bearing/crank and casing while doing it and keeping the bearings longivity to boot, I've personally found all explanations very interesting, cheers P.S. he's not the mesiah, he's a very naughty boy!!
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Post by unreliablesc on Apr 3, 2011 16:02:01 GMT
sorry but i cant leave this... it is basic engineering. if you are to design say a gearbox, after calculating what kind of gears and axle you need you calculate forces in z and x direction. then you proceed by selecting a bearing that will take all of the force in the z-direction for your target lifetime. then it's no need to consider axial force when you select 2nd bearing. as first bearing is a ball bearing it will i this case also take some of the radial load. same goes for mains, even if i used a gearbox as an example (that the only thing i ever have calculated bearings for). that beeing said i closed my PK engine today using a ball bearing
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Post by speeddemon on Apr 3, 2011 16:38:49 GMT
understanding women ?? im lost straight away, mad cunts indeed Sounds like the deepest possible understanding to me. A man walking on the beach finds a latern, rubbed it and genie pops out. A Genie says "Look man, I'm tired, haven’t slept a while, so you only get one wish” Man says "ok. I bought a new sports car and want to drive to Australia, so I want you to build a long bridge for me so that I can drive from England to Australia whenever I want. The Genie says, "Are you crazy, I told you I was tired, that requires a lot work, think about the steel, dirt, rock required, the anchors in the ocean, sorry cant be done" Man says "ok then, Give me the ability to understand women, let me know what they are thinking, feeling, why they cry, why the laugh, when they are sad, when they are happy and everything about them. The Genie sighs and says "Do you want that bridge in two or four lanes??"
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Post by Juan on Apr 3, 2011 18:08:07 GMT
Isn't it Husaberg who use bronze bushes in their motors rather than bearings? It was either them or Husqvarna anyway.
But I do appreciate these are designed for regular and frequent rebuilds.
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Post by gregpap on Apr 3, 2011 18:12:26 GMT
The similar "problem" of the crank in engineering would be a "ball-joint and gliding-joint beam" if you place a nu204 this transforms to "gliding-gliding joint beam", thats why i say the whole system bearings&crank would be free to move in the case, creating coaxial loads to the bearing cases... my above argument comes in line with amazombi's hypothesis that the bearings are free to move in working temperatures, and maybe that is the reason piaggio uses "Locking ring bearing"(number 12) www.sip-scootershop.com/EN/main/service/PartsCataloguesDetails.aspx?link=1&table=e48d61df-ab82-41e1-906c-83ce5ecd69b3&oc=e73d4525-29d4-4725-8c20-0d200f78f74bso imagine having every joint moving in a racing engine (20+hp) in a cases originally designed for up to 5-10hp.... these are my 2 cents guys.. p.s. sorry for my english, i hope not to get lost in translation...
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Post by amazombi on Apr 3, 2011 18:49:47 GMT
As I said already, the crank's axial position is fully defined by the ballbearing on the driveside, by the bearing stop in the back of the bearing, the circlip in the front and the primary drive nut. And it is radially defined by the bearing itself. With the crank being fully defined in the axial direction you only need radial definition on the flywheel side, and you use the axial degree of liberty for heat expansion. As unreliableSC has confirmed this really is basic engineering. I didn't want to sound condescending, but it really is something described on the first fifty pages of the book you get for any apprenticeship in metallworking in Germany. When studying mechanical engineering this is usally covered in something called "machine elements" (at least this is what it was called in my day)in the first semester. There is not a single race engine (or internal combustion engine) I have ever come across where the crank is fully defined axially and radially on both sides. This is a definite no go, it doesn't work.
Once again: This is theoretical. It's absolutely not necessary to know anything about engineering theory to rebuild a good engine. It doesn't change anybodies life, nor did it have an effect on my personal frequency of sexual intercourse. If I had been tempted to raise the subject it might have had a negative effect even. I just thought it would be ok to state the mechanical facts as they are since it came up here.
I'd still be interested in the reason for ballbearings right and left on some race engines.
Juan: Not sure I've seen one of more recent ones of these. It is a twostroke though, right?
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Post by charliec on Apr 3, 2011 19:23:06 GMT
i must say i havent read most of this on here so you may excuse my ignorance but ( there was a fair bit too read ) if they made the casing and bearing ( whatever damn bearing it may be! ) out of the same material wouldnt they expand at the same rate anyway? - so perfect fit all round ;D
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Post by Juan on Apr 3, 2011 19:23:21 GMT
I think they used them in both 2 and 4 stroke although if this remains the case since they were bought over I couldn't say.
It's been a long time since I had anything to do with dirt-bikes.
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Post by amazombi on Apr 3, 2011 19:36:16 GMT
i must say i havent read most of this on here so you may excuse my ignorance but ( there was a fair bit too read ) if they made the casing and bearing ( whatever damn bearing it may be! ) out of the same material wouldnt they expand at the same rate anyway? - so perfect fit all round ;D It's a case of an Aluminium saw blade cutting steel (which is never going to happen, as you put it), or of a steel crankcase. I think Triumph did that on some WD engines in WW II to safe aluminium, and some car engines had it for some time after that (my Volvo Amazon has a cast iron motor). I really did become quite unpopular a while ago though. There have been experiments with laser welded sheet steel gearbox casings in formula one recently, but that's so hightech it's not worth mentioning really. Juan: one would have to see the casings to understand why they did what. There is a good chance they did that to aid the floating of the crank though. Just reread Juan's post. I though the dirtbike engines had ballbearings in bronce seats. Apparently they have bronce bushes only, which marks them as fourstroke engines. You need an oilpump able to supply the juice with some pressure, the shaft then spins on a film of oil.
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