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We all agree that the EWP flows less than the standard pump by alot (maybe
only half to 1/3th as much?).
For the EWP's
we're trying, I agree, but they do make larger EWP's. At the same
time, I think most of us can agree that the stock pump flows too much for what
we're doing. Why would anyone slow it down by changing pulleys if it
really needed to be flowing that much.
But if you have less flow then the radiator MUST be larger for the engine
to obtain equal cooling.
Technically,
I agreed, but the difference in size might be insignificant, depending on how
much you change the flow.
This equates to more
drag. Now does the EWP save more energy than the ~3HP the mechanical
pump uses even when the extra cooling drag in factored? In other words,
does the EWP save 3HP worth of cooling drag? I suspect that the mechanical
pump is more effecient but can't prove it. Bill, Al, Ed and some of the
engineers can probably give us a good idea though (and have). No numbers
here, I'm just trying to piont out the real issue
Following
this same line of reasoning, you can install an eccentric shaft pulley the
size of a steering wheel, and then replace your radiator with an oil cooler from
a Lycoming. You'd be almost drag free :-)
What I would
like to see, is a dyno run, where everything is held constant with the exception
of the water (better make it Evans) flow rate. I'd be willing to bet
that the relationship between equilibrium temp, and flow rate will not be a
straight line. I would expect that it's more of an exponential
shape. My guess is that the stock pump flow rate is located far out on
this curve, such that a 10 gpm change won't make hardly any diff in temp.
OK all you
engineers, really let me have it now :-)
Cheers,
Rusty (I'll
abuse Ernest later)
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