The electric water pumps seem to still be very common on drag race engines.
My understanding is that they solve several problems peculiar to drag
racing, and are not applicable for the street. (Which doesn't explain the
usefulness on an autocrosser <g>)
One reason is to get rid of the fan belt. Seems drag motors have a bad
habit of ripping V-belts in half during a run. Of course, it's possible to
run the pump from the blower belt, but it's a big hassle. The electric
pump is simpler and easier.
Another reason is that water pumps don't work too well at high RPM. (I've
been told that the stock water pump in a TR3 will cavitate at 7000 RPM)
And the third reason is yes, to save power. Drag motors have no alternator,
so the only issue is the weight of the battery, which is quite small, only
big enough to last for the minute or so it takes to stage and run. Drag
racers (like many serious racers) look for anything that will make them
faster, even if it's only by .0001 second. (After all, find ten of those
things, and you are faster by .001 second, which might make the difference
between winning and losing !)
Randall
On Tuesday, March 16, 1999 6:40 PM, Kim and Kelly Alford
[SMTP:alfords@seanet.com] wrote:
>
> But the question is: Would the increased draw from the electric water
pump
> combined with electric fans increase drag on the engine from the
alternator
> (or generator), to keep up with the additional electrical demand?
Remember,
> alternators are only about 30% efficient.
>
> Kelly Alford
> 71 TR6
>
> -----Original Message-----
> From: owner-triumphs@autox.team.net
[mailto:owner-triumphs@autox.team.net]
> On Behalf Of Pete & Aprille Chadwell
> Sent: Tuesday, March 16, 1999 8:19 AM
> To: triumphs@autox.team.net
> Subject: Electric WATER PUMPS?
>
>
> This is probably not new to a lot of folks on this list, but a buddy of
> mine had a Datsun 510 street/autocrosser that he had fitted with an
> electric WATER pump. This was many years ago, so I don't remember the
> details, but the benefit was that no matter the engine rpm's, the water
> pump always turned the same rpm.
>
> At least I THINK that was a benefit! And I think it was supposed to
reduce
> some of the parasitic power loss of driving the impeller off the crank,
> just as electric fans do.
>
> Comments?
>
> Pete Chadwell
> 1973 TR6
>
>
>
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