Does any one know why crankshafts and camshafts develope a magnatism? It is a problem because the shafts attract minute particles of debris causing premature failure of the engine due to bearing failure. I work at a shop that rebuilds engines. Can anyone help?
Probably from forming. In the olden days, rumor has it, they made magnets by striking iron in a north-south orientation. Or something like that. (Maybe it had an eye of newt quench too, I forget.)
Magnetos at all? Or am I thinking too lawn-mower-ey...
Tim
-- "I have misplaced my pants." - Homer Simpson | Electronics, - - - - - - - - - - - - - - - - - - - - - - -+ Metalcasting and Games:
Got me also, magnefluxing and didn't switch it the other way? That wouldn't be good for cams and cranks.
I have never noticed this, but if it happens it is probably not a very strong effect. If you are worried I can suggest two things. First a machine shop may be able to demagnetize the shaft, they do this on small parts that they hold on a magnetic chuck.
Secondly, the premature wear might be avoided by having a stronger magnet in the oil pan as the this should catch most of the little bits in the oil.
This might be a non issue as the engine is designed so the crank or cam does not usually ride directly on the bearing or the lifter or rocker, but rather there is a hydrodynamic oil cushion that keeps the two apart.
It still works today: Take a piece of fairly hard steel (most mechanically hard steels are magnetically "hard"). Put it on your anvil orinted north-south, and beat the hell out of it (basically give it a hard enough whack that if it were sprung into a bend it would take a set). I've done this, and it works. Special quenches are unnecessary.
I presume this has to do with the anvil as an erm, for lack of a better term, magnetic "sink", and the steel has to be deformed enough to whack the domains into alignment with it?
Tim
-- "I have misplaced my pants." - Homer Simpson | Electronics, - - - - - - - - - - - - - - - - - - - - - - -+ Metalcasting and Games:
Try it. It is easy to do. I demagnetize things that attract iron chips in the shop by orienting them East/ West and smacking with a mallet. Some steels work much better than others, but no eye of newt required.
Dan
No, you can't hit it hard enough if it's on soil or wood! An anvil made out of rock will do.
Mark Rand RTFM
That was an old high school physics demo. Iron bar - demonstrated to be non-magnetic - does not affect a compass. Hand held with a couple of slaps on the end with a hammer - voila! attracts a compass. Regards. Ken.
Mark Rand wrote in news: snipped-for-privacy@4ax.com:
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