the Wasp
rrProfessor
Location: Vt
| sorry for starting another post on this but I started to search bearings on-line and I said "the hell with it" and I called a large US bearing company and this is what I was told,,
note,,
keep in mind the guy I talked too is a modeler and owns both glow and turbine model engines,,
1) some quality bearing manufactures use only a Circle, Triangle, Oval or other markings to mark their bearing,
2) a quality bearing the size in our engine should be marked in some way, if it's NOT marked in some way we should question it's quality !!
2a) a stamped letter in ink such as a "C" on the outside race only specifies "Lot", it has nothing to do with brand or size or application, although if this letter is the only marking quality should still be questioned !!
3) Skidding "as some OS owners have reported",, Skidding is a preload problem, this means the bearing is NOT preloaded,,
3a) a simple shim between the bearing and crank will preload the bearing,, the thickness of the shim is to be determined by fit and trial, more or less this means you are on your own to figure-out how thick the shim should be, .010 should be more than what's needed, .004 should be closer to what's needed,,
4), a good quality bearing in the size we use in our engines with the correct preloading should not show any real wear until 29 hours of engine running time at 17,000 RPMs,,
4a) a quality bearing should last for 500 Million revolutions, yes 500 Million revolutions (if preloaded correctly),,
5) a quality "quality" SS bearing should have the same hardness as a Chrome Steel bearing "60 Rockwell",,
6) yes, if stock is low a bearing manufactures may buy stock from other manufactures, so if this manufacture buys stock then sells stock to a 3rd manufacture then there could be a problem in quality, specially if the bearing is NOT marked,,
so this is what I suggest to do when replacing a bearing,,
1) buy a good quality brand bearing that is marked,
1a) get a 60 Rockwell SS bearing so it wont rust,
2) add a .004 shim between the bearing and crank and hope for the best..
Jim
the wife wont let me get a Monkey !!,,, damm, can't have anything |
and can see now because of the crank design how the end float can be there.
