Originally Posted by Esprit Aviation
Yeah I have heard failure stories, but have had good luck w/ mine. The cars are strictly street driven. A Lotus Esprit Turbo and a 1st Gen Mazda RX-7 w/ the rotary. Most miles are on the Lotus and it has operated fine since I purchased the pump in 2004. It has been driven quite a bit and as often as possible in the winter, weather/salt permitting. It has no thermostat (runs way to cold), but w/ the success of the Mazda coming up to the proper temp and continually recirculating w/ the external bypass stat, I will fit one to the Lotus. No hot spots and I get great heat too.
Just found this from the website: (Note the pump is used w/ the Davies Craig controller)
"Question No. 9
Will the fitment of an Electric Water Pump be a drain on my electrical system?
The extra current is very little. About 90% of total motoring time the EWP will run at 10% of its maximum speed using about 2 amps. Being in nylon, the impeller can have aerofoil cross section and the tip clearances can be very small. A mechanical pump has to perform at 600 rpm and 6,000 rpm and it cannot be efficient at both these speeds and all speeds in between. Furthermore, as the power the pump requires to operate increases as the cube of the speed - when the mechanical pump is operating at the higher speeds, as it does, as a car passes through its gear range, its ‘robbing’ engine power in the order of 6 to 10kW. The EWP® which uses at maximum speed 9 amps x 13 volts gives 120 watts at say 30% efficiency from the alternator to hydraulic power means about 0.4 kW to drive the EWP®, when it does operate at full speed."
That makes a pretty big differnece. i would let the lotus run cold. Running one hot is very bad. Have you tried the washer trick where you use a washer in stead of a thermostat. for chevy and ford you can buy them already purpose made to replace the thermostat.
Are you using the full tilt controller from the manufacturer. I would assume this is really important part.
Yes that is true they use little power when hooked up correctly. But you still need to move the water. if its not it will over heat the engine. It is also true the stock pump can cool the engine at heavy load. most electrics arent going to go for max load for very long. Most engine can produce more heat than the stock pump can carry away when they are running at there absolute max.
But it should work fine in a lotus or other small engine. since they dont produce alot of power they also dont make a lot of heat. Combined with alum rad and things cool off very quickly. But they same on a 500hp chevy and the pump will be working at its maxs and overloaded by the end of the 1/4 mile track and need time to catch up. running full tilt for serveral miles and you will need a pump that can do everything the factory one can do and more.
If the pump uses that much less energy than stock it is pumping that much less water than stock. actually to make the pump do everything the stock one would you would use more hp to run it. since the pump needs to run with the same amount of power and still account for the loss in producing eletricity and the eletric motor. the stock pump with a belt is pretty dang good when you think about it.
hope this helps.