The V8 Owners Forum -

Ian Anderson wrote:Stevie

It will still give you 14 volts even although the belt is slipping. How many revs does your engine need to turn to get 14 volts - a little over idle I would guess - so it wil be on 14 volts.
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Ian

Strange thing with this alty, originally off my nieces Fiesta, is that it won't clear the charge light until it has been blipped past 2000 rpm, then it will stay off even when the speed drops down to 400rpm idle. Apparently not a problem, as it has been like it for over 5000 miles with never any battery power issues.
I'm surprised modern cars don't have some sort of centrifugal device that lets the alty drive slip when it reaches a certain rpm.

Holy thread resurrection Batman!

I’ll be fitting a Davies Craig electric pump to my 3.9 V8 soon, and I’m in two minds about leaving the standard pump ‘as is’ with just a few holes in the thermostat or stripping the impeller out? I can’t find any blanking plates on the ‘net…

Do you need to retain the pulley?
If the belt routing works without I would make/buy a flat blanking plate.
If you need the pulley I think I would remove the impeller - or mount an idler pully to your flat blanking plate.
I wouldn't run with two pumps - seems a waste of energy.

Thanks! The std water pump will sap a bit of power, but the electric Davis Craig will be fine. I have a twin big batt setup for the mooooosive winch up front and the smaller one behind.

Hard to beat the simplicity and reliability of a standard mechanical pump. If it ain't broke.....