One of my suppliers is listing the EWP pump which can be mounted remotely from the engine in a convenient position to hook up to the bottom rad hose. The standard water pump can be left in place to aid connection and the impeller removed if it were felt to impede flow. Obviously there would be no need to run a belt to the old pump. Where the old pump has no hose connections (all Z models), a blanking plate could be fabricated to cover the area if preferred.
An electronic controller is used to vary voltage and govern pump speed and a thermostatic switch turns the pump on and off as required. The engine thermostat would be removed and you would need to experiment with various restrictor plates to match flow to desired cooling (open with no thermostat would lead to increased flow through the radiator and probable impaired cooling effect.
There are other varieties available, but data on this one was to hand:
300-1300 UK gallons per hour or 20-80 litres per minute
Max pressure 30psi
Temperature range for correct operation -20 to +130 degrees C.
Motor life estimated at 2000 hours at 80 degrees C.
Current draw 7.5 amp max.
Weight 900 g
Hose size 1.25" - 2" via interchangeable adapters
Overall dimensions 128mm x 131mm x 77mm deep (excluding outlet.
Price to be confirmed, but a kit including pump, controller and thermostatic switch will be around £225 - £250 + VAT.
A smaller version is available for pumping fluids to chargecoolers, water cooling for brakes and supplementing flow to heater matrix, with 3/4" push fit couplings. 13 litres per minute, 15,000 hours motor life at 80 degrees C. Cost in the region of £85 - £90 + VAT (but need to check). I have a version of this with the chargecooler associated with the Stillen supercharger intercooling system....very efficient and reasonably quiet in operation.