Trevor Phillips Posted February 2, 2003 Share Posted February 2, 2003 I'm intending running an electrical water pump this season on my BDA. Flow rate is adjustable from the dashboard. This means that the water pump pulley is becomes free. As I need to hook up an alternator, is there any technical reason why, with the right sized pulley on the alternator, I couldn't run the belt off the water pump instead of the crank pulley? Racing pics and items for sale here Link to comment Share on other sites More sharing options...
Lawrence_Z Posted February 2, 2003 Share Posted February 2, 2003 I'm not too clear on what you mean.... Does the engine have a bypass loop? or heater circuit in use? You may have to remove the water pump if it's restrictive to water flow for the electric pump. otherwise it'll just sit there doing nothing Lawrence Link to comment Share on other sites More sharing options...
Trevor Phillips Posted February 2, 2003 Author Share Posted February 2, 2003 Lawrence This is a race engine, we will only use it occasionally on the road. 😬 The kit suggests you can remove the impeller and leave it idle if you don't want to use it. However, to drive the pulley you would need to leave the impeller on. The electric pump should have sufficient power to run the impeller. Quote: EWP® water circulation pump This exciting NEW concept offers more available engine power, better mpg, improved cooling with quicker warm up and longer engine life. It is supplied in kit form to replace existing belt driven water pumps. Use with an adjustable electronic controller which supplies exact voltage to govern water pump speed to achieve desired cooling requirements. Owners of older cars with troublesome original pumps have also achieved new found cooling reliability. The existing belt driven pump is inefficient in that to allow sufficient circulation at low speed, the flow generated at medium to high speeds is not required and is wasteful of engine power as is the energy required to speed up a mass of water through a restrictive radiator during hard acceleration. Water circulation ceases on turn off and engines are often "cooked" by switching off after a high speed run. The water pump may be fitted in any location where it can be connected into the bottom hose, adapters are supplied to suit various hose diameters. It is not necessary to completely remove the existing water pump. The pump pulley can be disconnected and a shorter belt used, the pump will then idle and offer no resistance to flow. Alternatively the old impeller may be removed from the shaft. Racing pics and items for sale here Link to comment Share on other sites More sharing options...
Lawrence_Z Posted February 2, 2003 Share Posted February 2, 2003 Trevor However, to drive the pulley you would need to leave the impeller on. The electric pump should have sufficient power to run the impeller. Where is the alternator drive coming from? In what way will the electric pump run the impeller? Lawrence Link to comment Share on other sites More sharing options...
Trevor Phillips Posted February 2, 2003 Author Share Posted February 2, 2003 By my reckoning as a non-techie, the flow of the water [driven by the electric pump] causes the impeller to turn as normal [possibly faster] thereby turning the pulley. Connect up by belt to the alternator pulley and the alternator then generates the required electricity. It would mean that I could use a shorter belt [the crank pulley being further away]. Racing pics and items for sale here Link to comment Share on other sites More sharing options...
Tony C Posted February 2, 2003 Share Posted February 2, 2003 Sorry to be flippant, but that I'd like to see Link to comment Share on other sites More sharing options...
Miraz Posted February 2, 2003 Share Posted February 2, 2003 If I understand what you are trying to do then it's not going to work...if it does then you will have just invented a perpetual motion machine. The flow of coolant through the pump will not be able to drive the alternator well enough to generate the power to replace the energy used to pump the coolant in the first place....you will probably find that the impeller will turn very, very slowly or not at all and will obstruct coolant flow. Edited by - Miraz on 2 Feb 2003 22:17:20 Link to comment Share on other sites More sharing options...
Lawrence_Z Posted February 2, 2003 Share Posted February 2, 2003 Trevor The impeller will not turn with water flow..... The alternator will have to be driven by the crank pulley. Lawrence Link to comment Share on other sites More sharing options...
Trevor Phillips Posted February 2, 2003 Author Share Posted February 2, 2003 Many thanks - I will drive it from the crank pulley Racing pics and items for sale here Link to comment Share on other sites More sharing options...
Foxy Smith Posted February 3, 2003 Share Posted February 3, 2003 Trevor, There was a good Dave Walker article on fitting the EWP in CCC. I don't know when it was and only know about it as Thinkautomotive have it on their notice board on the trade counter. DW's opinion that fitting the EWP without removing the original water pump impellor was what he called a "negative enhancement" read waste of time. I would have thought for your racing it would be imperative to remove the impellor and minimise uneccesary losses. For my money I'd be inclined to leave the pully in place so that cam belt arrangement remains the same and just remove the original impmpellor. Surely much easier than farting around trying to find a new cambelt that fits with one pully absent. Alan Link to comment Share on other sites More sharing options...
DohNut Posted February 3, 2003 Share Posted February 3, 2003 Although in the same CCC Article mentioned I seem to remember that Dave did remove the whole impeller / pulley arrangement and blocked the hole that was left by the shaft. In which case he would have had a shorter belt bypassing the (now absent) pulley. He did make other alterations at the same time such as fitting a smaller alternator so has was forced into the faff of finding new belts etc. While Mr Walker ,as ever made a nice job of the installation, he left the large alloy water pump casting on the engine and then fed the water to the Craig Davies pump which was held on another braket somewhere else and from there to the rest of the cooling system. It did strike me that you were leaving half the old system in place. The ideal would be to mount the electric pump directly onto the pump block in place of the alloy pump housing, it would be a larger engineering exercise and would subject the pump to lots of vibration but it would remove weight and reduce the number of components / joints. OR for the cheapskates - aparently the motor in the pump is the same as the one used by a Big bikes fan motor (Hyabusa or Blackbird??) It would be possible to mount the motor on the end of the old belt driven shaft and get an electric water pump that way, it would not be as efficient as the craig davies pump as you would still be running with the bent metal impellor but you would still have all the benefits of contstant flow independant of crank speed and circulation after shut down. It would be dependant on the particular motor - I think that one without cam belts would make life a whole lot easier. Nick Link to comment Share on other sites More sharing options...
Peter Carmichael Posted February 3, 2003 Share Posted February 3, 2003 The pump motor is the same as the one on the Blackbird radiator fan I have kicking around waiting for a project. I hold the opinion (and have written as much several times before now) that the installation instructions for the Davies Craig pump demonstrate a lack of understanding of the fundamentals of vehicle cooling. All of their installations advise the removal of the thermostat, which subjects the engine to unacceptable thermal gradients across the head. They make bold claims for improved control of temperature (based on an electronic sensor and control unit) but are passing off a deception. What they describe seems plausible, but it can be readily shown to be a deception by fitting a second temperature sender in your radiator circuit on the radiator return pipe. While the radiator feed pipe will be maintained at a constant temperature, the radiator return temperature will fluctuate wildly. The only valid use, which may well be what Trevor is planning, is for race use where you run the pump at full speed pretty much all the time, blanking off the appropriate amount of radiator to suit the ambient conditions. Speed control of the pump alone does not provide adequate temperature control and has the potential to damage alloy engine heads. Link to comment Share on other sites More sharing options...
Graham Perry Posted February 3, 2003 Share Posted February 3, 2003 What Peter says is pretty well the way I run mine. I have two electrical circuits , one using the stat. to warm the car up, and then a second one that is continuous that I switch to once its warmed up for some serious blatting Link to comment Share on other sites More sharing options...
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