electric water pump

[spotaneagle]

Originally Posted by i-DSi

Sorry Sludgy, but there's no flaw in my theory.
The waterpump always circulates the water in the engine block and to the cab heater, also with a completely closed thermostat. I'm 100% sure.
The thermostat will only change the waterpath: instead of returning immediately to the engine block it first goes to the radiator.
The circulating is necessary for an equally divided heat in the block, as I posted. Imagine the stress around the exhaust valves and exhaust ports if the water doesn't flow. Water will start cooking over there already after a minute if there's no flow and the headgasket will break because of stress.
No waterpump that I know is 'throttled'.

owned

[Sludgy]

OK, I looked it up on Wikipedia, and watzisname is right. But I still like the idea of lowering water pump losses. Water pumps and radiator fans are designed for the maximum load an engine can put out at the highest possible air temperature... say 120 F in the sun in Death Valley towing a trailer.

So, an electric water pump that runs at 10% speed at 0 degrees F, and 100%at 200 F would save a lot of energy and not cause block and head problems.

[i-DSi]

Originally Posted by Sludgy

OK, I looked it up on Wikipedia, and watzisname is right. But I still like the idea of lowering water pump losses. Water pumps and radiator fans are designed for the maximum load an engine can put out at the highest possible air temperature... say 120 F in the sun in Death Valley towing a trailer.

So, an electric water pump that runs at 10% speed at 0 degrees F, and 100%at 200 F would save a lot of energy and not cause block and head problems.

You're correct Sludgy. Allthough it depends on how you want to reach the 10%. Just letting the pump drive at a lower rpm is very difficult and the power needed will not be 90% less then 100% driven. Maybe blockwave is better, but I'm not a specialist in that area.
If I may suggest another way to go to safe fuel by watertemperaturemanagement: install an electronically managed thermostat.
Aim of the game: going for a high temp when no power needed, decrease temp when you need power. It's done by BMW in the 3-liter 6-cylinder if I'm not wrong. I'm not sure, but if I remember well the temp goes up to 110?C when idling and no power demand by driver. And it drops to 85 or 90? when the driver floors the car. Efficiency goes up at the higher temps (less heat loss in cylinders). But it will deliver less power at this high temp (less oxygen/air can get in the cylinders because of the heat).