C D water pumps

[Propshaft]

Silly question but are these electric pumps just adjustable on the flow rate or are the coupled into a thermo switch

[trunt]

If used with a controller like the Davis Craig once they get near the setpoint temperature the speed is controlled on a ramp, the hotter it gets the faster they pump. On warmup they run intermittently to allow the engine to warm up as the bypass and thermostat is supposed to be removed.

I, and others have found that in colder temperatures it struggles to get up to temperature so leaving the thermostat and maybe even the bypass in seems to be the best configuration. There are a few threads discussing this.


Or..
Neil (flying farmer) simply runs it at half speed through a resistor.

[Propshaft]

Thanks for your reply

[bullstarz]

Theres 2 way they can be controlled. Either PWM which (sort of) reduces the voltage so the pump runs slower or they can turn on and off. Mine was set up to start running 8volts which was 1/2 power. Up-till 50°C it was on for 3 second off for 6. The 51-70 °C on for 3 off for 3. 71°C on permanently with the power slowly rising to 100% (12-14 volts) at 95 °C. Kept the thermostat in so it would warm up quicky

[Triumphman]

I thought the advice was to remove the stat?

[trunt]

I

I thought the advice was to remove the stat?

It is.. but I (and others) have found that when it’s cold the inrush of Ice cold water when it’s pumping intermittently prevents the engine from getting up to temperature and it stays in the “intermittent” stage. This is not ideal and the heater has no chance! Davis Craig actually suggest that the thermostat is installed in “cold climates” but extra holes are drilled to provide a trickle of water to the temperature sensor so it can read.

For me with an efficient radiator no mechanical fan and a spoiler helping, it only takes about a 40 degree day before this happens.

I have absolutely no issues with the stat in, In the summer I run at 90 degree setpoint so that the 83 degree stat is fully open and stays open, in the winter I drop it to 85 so it’s nearer the stat. As I have an early manifold without the foot I left the bypass blocked, (the heater provides a bypass anyway - if it’s on) if I had the later manifold with the foot I think I would have left it in place.

[jbuckl]

I bought one and decided not to fit it .

its all still in the shed.

has the earlier controller…. LEDs not screen.

if any one wants it?

Pm me.