Thread: Electric water pump for 3.9 V8 ?

Yesterday I was sentenced to 'clean out Shed'...and buried deep in the piles of Very Useful Things, I found a DC 'Electric water pump' and its associated Controller.

Blurb on the box claims the pump is big enough to handle up to 5 litres of naturally - aspirated engine... According to the rhubarb, the thermostat is removed, and the water pump either removed and a shrter belt fitted... or the vanes are removed/chopped/whatever - which keeps the same belt and lower hose connection point...which is where the pump empties into... The bottom hose is around 5 years old, so heading towards a strategic replacement...

Anyone done the conversion?
Was it worthwhile as far as fuel use goes ?
Any REAL increase in available engine power ? - Something you can feel...not just 'what the box sez..'
Would you bother doing it again?

Sarah has done over 240K on the original pump, no leaks or noises...
Or should I wait till the green stuff starts leaking out around the shaft ?
- I don't see the point in generating work for little or no tangible gains...

The Lady Sarah, '95 Classic Vogue SE, with working air suspension... but we won't discuss the rain inside the car from the ...'sun' roof...

No hard facts but maybe some simple physics to back up my opinion that these are a gimmick; the power to drive the electric water pump is generated by the engine, via the alternator. This energy will not come for free- you convert it from chemical to heat to linear (piston) then to rotary (crankshaft) motion, then to electricity then back to rotary motion of the pump impeller, then to movement of the fluid through the coolant system. Your standard water pump has less steps in the process from chemical energy to rotation of the pump impeller, so less stages of inefficiency.
240,000km on your original pump, why introduce an extra source of unreliability for probably (almost certainly) zero gain?