Just about to start the cooling system upgrade with the new Passat radiator and a 12 inch Spal fan. I was also thinking of an electric water pump Davies Craig ewp80 and removing the existing mechanical pump. However just had a thought that the heater won't work properly with the electric pump as it pulses and works via its controller. My simple mind would be that another small pump would need to be installed on the heater pipe work which is switched on every time the heater/fan is switched on. However sounds like more pumps than I really want. Only trying to placate my wife who likes warm feet as mot much heat seems to get to my side.

If anyone has installed one on a Spyder/Libra and a diagram is available I would be very grateful

I have researched this pretty thoroughly, and am sticking with the standard pump, in a pretty much standard VVC 160. I think you have to have a very good reason for going to the extra trouble and expense of an electric pump with very questionable benefits. For one thing, you have to be sure that you will actually shift a greater volume of water through the system. You may well achieve this in other ways, such as optimising the pipework, taking care to avoid diameter changes and steps in pipe joints, which will deter good flow in just the same way as roughness and obstructions reduce gas flow in a cylinder head. On the subject of which, it would be worth cleaning up the water-ways in the top of the block and in the head itself - especially if the head is coming off to improve the head gasket situation. There is at least one extensive review in the old TGTM archive which sheds a good deal of light on the subject, also referring to the importance of persuading as much air as possible to actually pass through your nice new radiator rather than avoiding it. So far as the good lady's feet are concerned, I am given to understand that suitable boots are available, though the price may be un-palatable.

If you have a standard heater unit/control setup, with the direction lever set to 'down' all the air is blown into the passenger footwell as the unit is above there.

SAS

Thanks for the sound advice. Everything on the head front and pipes is ok as I had a rebuild last summer and did all the cooling hoses etc. The Metro rad is right on the limit and as i go Continental quite a bit in hotter climes I feel the larger rad is essential. I will go with the fan and new rad and see how we go.

Re the good ladies feet, who am I to argue as to who should have all the heat!!! Our last car had no heater at all so she is being spoilt anyway.

The Davies Craig pump (bottom right below) works fine alongside the existing belt driven pump.

All you have to do is to fit a simple thermostatic on/off switch (top left below) to make sure that the electric pump doesn't start up until the thermostat is open.

I used one on mine and it increased the cooling efficiency markedly. It never overheated even though I was using a Laminova oil/water intercooler (centre below) so the heat from the engine oil was also being transferred to the cooing system.



I wired mine (through a relay) so that it was constantly live which also prevented heat soak problems. The pump would run for a minute or so after the engine was off keeping the water circulating through the radiator.