Electric Water pump

mikecoombs

Active Member
Has anyone tried the Mezier electric water pumps that are available for the Rover V8? Add says they pull 7.5 Amps which together with the electric fan would draw about 18 amps or a total power drain of about 225 watts. In theory that is a huge drop on what the engine driven fan and water pump use, particularly down low in the rev range. On the other hand I fitted an electric fan years ago and it just couldn't pull enough air for extended wide throttle openings, I could watch the temp gauge go up! However I could delete the thermostat and that significantly improves the water flow.
 
Taking out the thermostat is not always a good idea as it can significantly alter the character of the coolant flow pattern around the engine. This can mean hot spots develop.
 
True but the electric pump should adjust the flow according to the temperature and when I was in central Australia I ran the car without a thermostat for years without a problem as it was the only way to keep the engine cool enough as even when fully open they cut the flow in half. I see the better coolant flow from an electric pump, which doesn't rely on whatever the engine is doing for power, as a big plus. Getting enough air through the radiator is also a bit of a challenge though modern motors may be more efficient than the unit I used in the 1980s but I didn't have air con and transmission and power steering coolers hung in front of the radiator back then.
 
As I understand it, the thermostat should always be removed when running an electric pump. The control unit for the pump, as you say Mike, takes over by varying the speed of the pump, therefore the amount of coolant flowing around the engine. I've heard about some people upgrading their radiator to a 3 core one, which would be an option if temperature was a concern.

With regard to electric fans, this is worth a read:
My cooling project
 
On my 60s mini cooper there is a thermostat blanking sleeve to aid cooling on tuned engines.
Takes the place of the stat,made of brass with a tube that sat further into cylinder head to alter flow.
Could prob use on p6 but may not give a good heater output.
Clive.
 
On my 60s mini cooper there is a thermostat blanking sleeve to aid cooling on tuned engines.
Takes the place of the stat,made of brass with a tube that sat further into cylinder head to alter flow.
Could prob use on p6 but may not give a good heater output.
Clive.

Hi, I'm not sure what that achieves because in the Mini that leaves either a pocket of hotter water in the roof of the head casting or an air pocket that would be difficult to bleed out, neither would be ideal. Plus the thermostat is in a different orientation in the V8 so wouldn't do anything.

Colin
 
The sleeve was made by BMC/Leyland special tuning dept,it did have some small drilled holes in the tube section that fitted in the head.
You also had to plug the thermostat by pass circuit.
Here is the sleeve.
Clive.

BAC-388.jpg
 
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I used to work for Rover involved with engine development team and getting coolant flowing correctly round an engine was a time consuming and often frustrating exercise. Air flow round the engine compartment was also critical. I can see that an electric pump would have many advantages but even starting from cold, hot spots can easily develop if the flow is inadequate in a particular spot. Modern easily available kit such as an infrared thermometer would make it easier to check things if altering the cooling system.
 
The Mezieire pump is a bolt on that replaces the belt driven pump. Motor is where the pulley is normally. I presume that means that the flow through the engine is virtually unchanged except for the mechanical thermostats removal. I could of course modify an existing thermostat so it was always open, therby replicating the standard flow but given my experience here in summer, particularly in traffic, removing the restriction is a benefit in itself. Being able to vary the flow as a function of engine load rather than speed is also a plus, particularly in combination with an electric fan, once you know what the mimimum required flow is to prevent hot/cold spots. Internally to the engine, I am presuming Rover and GM have already done the work to sort that out and have sized the pump to provide the minimum requirement at idle.
 
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