The Stovebolt Site Forums The Shop Area The HiPo Shop Electric water pumps

Has anyone used any electric water pumps for engine cooling?

If so, any experience w/ the Davies-Craig type electric water pumps?

Thanks, Lee

Hi Lotusboy, nobody has been responding so I will give you all I know, which isn't much. The only electric water pumps I'm familiar with are designed for intermittent use, ie. a drag car. If there are some out there intended for continuos duty I am not familiar with them. The question is why an electric pump? The factory has been driving them with the crankshaft since day one, and it seems to work pretty good. If drag or volume are your concerns, there are high volume low drag pumps available. Take a look at www.speedwaymotors.com for some examples. I believe Edelbrock and Weiand both offer them.

John

Hi John,

Thanks for the reply. Actually, I am currently running an electric pump on my 85 Lotus Esprit Turbo.

Two reasons for me asking:

- Wondering if there are any different set-ups or control methods w/an electric pump that anyone else is using. I know that there are several pumps offered that target the hot rod community.

- There is quite a bit of horsepower freed up by eliminating the stock crank driven pump. Once again, I had wondered if anyone had dyno figures for a comparison on any particular vehicle, stock vs electric.

Thanks again for your reply.

Regards, Lee

Hi Lee,

A company I couldn't think of yesterday was Stewart Components. They offer low drag water pumps, I think they got their start in circle track racing. Their website claims a 2.26 horsepower loss at 4000 RPM, a nonfactor in my book. A few years ago one of the magazines, I think it was either HotRod or Car Craft did a water pump dyno shootout. If I remember correctly their conclusion was the same, when using a low drag water pump the power loss isn't worth worrying about.

John

My 9,000 rpm rotary engine in my Mazda still uses a mechanical water pump. It has electric power steering but the water pump still works fine from idle to redline, doesn't sap much power.

Thanks for the replies,

I suppose a low drag, purpose built pump, would be similar to underdriving it to save power.

I just figured there would be more benefit from lack of belt and it's losses, etc.

Lee

the only app that i have run into is for intermittant use...something to think about is any HP you save with the electric water pump is going to be offset with additional load on your alternator, your net increase is going to be close to nil

For some reason, many people think that the alternator is there anyway, so why not use all that free electricity to power things like waterpumps and fans. They forget that the alternator draws more power from the engine when the load increases and that even more power is required because the conversion process is far from 100% efficient. There would be no fewer belts, just one less pulley, unless you were going to run a total-loss electrical system and charge the battery between runs.

Boyd Cottington put an electric waterpump in his Alumitub Hotrod, but I think that was for space considerations, as was the air-shifter.

would a 3 core radiator and underdriving the water pump be a sallution ?