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Water pump Vs RPM


Yowzer

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So your waterpump is designed to operate most efficiently around the 2-4k rpm mark. In a racecar style situation where your engine could happily be spinning double that, your waterpump will be outside its efficiency range, and sapping engine power for no good reason? As well as potentially cavitating and doing a shitty job of pumping coolant?

So that's not really a question. My question is, how much coolant flow do you really need through an engine? Can you, for example, gear down your waterpump by 50% or so for track purposes without causing ill effects to the cooling capabilities?

Discuss away. This stuff is interesting.

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They are expensive though, smaller pulleys are a lot cheaper.. I think this more what he was getting at?

Interesting subject. I can't really comment, but I guess it depends on how fast an engine heats the water? Some tests using a coolant temp log and thermostat opening times should answer that. Things like turbo's may boil the water if it's moving too slow?

Useless post really :lol:

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both those links were over priced,

you hardly need the controller, set the flow rate with a pot or run full noise,(all sorts of motor controllers out there, even a plc is cheaper than that fan controller unit)

have a electric fan running on a thermostat,

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  • 2 weeks later...

You gota love these guys, they miss the point every time. They always like spending other peoples money. LOL

Increased crank speeds also affect the alternator and power steer pump as well if fitted.

Run an race spec Escort years ago that went well past 8K and had an issue with the water flow and it fried alternators regularly.

What I ended up doing was using a smaller crank pulley, it solved both problems at the same time.

I just did the percentage change calculations and found one the right size (about 30% in my case), a bit of machining to make a custom 2 piece crank pulley. No more over heating on long runs and no more fried alternators.

Only complication was the loss of the factory timing marks.

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other 'oldschool' trick was to remove every second impeller blade (only advisable if you have an even number to start with .......) some factory pumps used on a variety of engines are identical except for impeller , theory is you are trying to stop either too much cavitation at high rpm and/or water can pass through radiator before it is cooled properly , as mentioned above changing pulley sizes is a good way to solve lots of these issues if practical/possible/affordable

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They are expensive though, smaller pulleys are a lot cheaper.. I think this more what he was getting at?

Larger, surely??

Yeah on the ancillaries.

But if you go smaller on the crank then you kill multiple birds with one stone.

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