Ed,
Thanks for the good advice. What is a typical Reynolds number for
engine oil flow? Are we talking 1000 or 2000? And I realize that with
a larger passage diameter (area) results a lower Reynolds number
given constant volume. Sorta like line loss in an electrical system........
Thanks again,
Skip
At 11:07 AM 10/18/2006, Ed Weldon wrote:
>Skip--Only use it on the as cast surfaces. What you're trying to seal in is
>the casting core sand particles, sand grit from the foundry final cleanup
>process that involves the uses of abrasive grinders as well as tramp rust,
>scale and dirt in corners and pores. I would not attempt to use it on any
>machined surfaces especially where the surface can't be roughened to provide
>a good grip for the coating. Don't attempt to put it in any drilled holes.
>You'll likely restrict the flow rather than improving it. If you're
>marginal with oil feed holes drill them larger or at least chamfer the edges
>at the openings (Which will likely help your own feelings more than the flow
>losses of the oil)
>
>I remain unconvinced that any improvement on the surface finish of oil
>passageways will have any measurable effect on flow rate. Virtually all oil
>flow is in the regime of laminar flow where surface roughness is not a
>factor. The classic engineering pipe friction curves for friction factor at
>various Reynolds numbers shows this. It's a whole different issue for thin
>liquids like water, gasoline and alcohol. In the size lines we use the flow
>is turbulent and pipe roughness counts. But nowhere near as much as the
>actual area of the pipe flow path (the diameter in most cases).
>
>Ed Weldon
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