What Is An Electric Water Pump? – And Why Should You Care

09/07/2019 12:00AM

Life sometimes gives us questions to ponder. Why is the sky blue, are The Rolling Stones a better band than The Beatles, should I have pineapple on a pizza, and what is an Electric Water Pump (EWP®)?

Unlike the others, the answer to what is an electric water pump is surprisingly simple to divine.

An Electric Water Pump, or EWP®, is an electrically driven unit that pumps water or more commonly called engine coolant. There, sounds simple. But wait, there’s more. One immediate benefit of an EWP® is in the name, the word ‘Electric’.

Because it utilizes that amazing and invisible power, an EWP® isn’t reliant on the spinning of a crankshaft, the rise and fall of conrods, and the pulsing of injectors. They work as long as there is juice in the battery. This means that if a car or truck or bus has been running for a while and the ignition gets switched off, a control device can keep the EWP® running-on after hot engine shut-down. This is especially crucial in automotive high load areas or in motorsport.

Consider a drift car, running a high revving petrol engine and fitted with a turbo. A talented driver can pound a drift car around a circuit and the engine will be constantly working hard. The driver gets to the end of their run and switches off. A mechanical water pump them immediately stops working. This means cooling fluid is no longer pushed through the engine internals and through the radiator. This can lead to severe damage to the engine and potentially the radiator as well.

Another benefit of an EWP® is the constant pressure and flow rate. An easy comparison is a child’s toy fan. Blow gently upon the vanes and it’ll spin slowly. Give it a good huff and it’ll spin hard before winding down. That’s a mechanical water pump, rising and falling with engine revolutions.

An EWP® suffers not from this, and EWPs from Davies Craig, with flow rates of up to 150 litres per minute, will CONSTANTLY deliver flow, as they’re not dependent on a crankshaft and belt to spin.

And because they’re electrically powered they’re not sapping energy from the engine, allowing this extra power to go to the drive wheels. This means less strain, better fuel economy, and longer lasting mechanical parts. The EWP®s are a good deal smaller, which means less weight, better efficiency, and can be mounted in certain positions to help tidy up an engine bay.

Which EWP® have you got fitted to your set of wheels? Share your thoughts and pix via our blog’s comment section.