Quote:
Originally Posted by McDeLtA_T
You must keep the rpm low for your break in period; as RPM or radial velocity increases (w), your acceleration (a) is increased as a square. a=w^2*r. Remember from physics, F=m*a? The higher the rpm, the higher your con rod's and pistons have to accelerate to get from TDC to BDC. This in turn creates excessive force on your crankshaft bearings. This force slams the unworn-in bearings and creates terrible form-ability between the crank journal and bearing. Your bearings need to form to the journals uneven surface to properly allow a thin film of lubrication to separate the two surfaces.
It is imperative that you wear in your bearings properly first or else you can cause a majority of problems. This also goes for the rest of your engine. This is why they specify you to maintain an rpm below a set value in the operating manual. See this link below for info on bearing wear problems, I hope this scares anyone from neglecting the advice of the manual...Your car may run fine for the first 30k but it can lead to a host of problems in the long run if you don't "wear-in" your car properly.
http://www.bobistheoilguy.com/bearin...aranalysis.htm |
Please refrain from using ignorant scare tactics to misinform people, I'm not sure what you have to gain by peddling bad info but no where on that chart of common bearing issues did it mention anything to back up your misguided statements about wearing in bearing...
Do what you will with your own car but don't try to explain things you don't understand, coming in here talking about physics, with no understanding of the subject at hand makes you look credible to people looking for actual information but to anyone who knows how a bearing works you look like a fool.
To clarify the mess you laid out for everyone, If a bearing touches your crankshaft it doesn't "wear-in" it wears OUT, bearings should only ever touch the journal (rod or crank) when the engine is off. that's the ENTIRE POINT OF FORCED OILING. The oil floats the crankshaft and rods on a thin layer of oil under pressure, its called a Hydrodynamic bearing.
This idea you seemed to develop that a bearing needs to form to the uneven surface of a Journal tells me you have no experience whatsoever in engine assembly or precision...anything. The crankshaft has hardened and ground surfaces for all journals, aswell as the seals on both ends. your average OOR (out or Round) condition on these surfaces will be less than .00005" that's "fifty millionths" of an inch, there is no "wearing in" of bearings, there is no "uneven" surfaces
It's posts like this full of misinformation that give forums and the internet in general the reputation of being full of know it all's who know nothing.
