New water pump, 8mm bolts?

[Philippe Holland]

Hello, I've just received a new water pump from one of our reputed suppliers and I noticed "8mm bolt"
written on the pulley face pointing to where the four bolts go that hold the pulley on.
Is this a known modification?
Seems odd to remanufacture a pump and then go metric...
Cheers,
Philippe

 

[Philippe Holland]

In case you are fitting a new water pump, I can confirm that the new standard water pump I got from Wadhams uses 4x 8mm bolts to hold the fan on and 3x 6mm bolts to hold the pulley on instead of the UNC (on early cars) and UNF bolts as standard.
It seems odd to go metric.

 

[Mike Allfrey]

Hi Philippe,

You are probably better off with 8 mm bolts. I have always regarded UNC and UNF threads as being crude. Look at a drawing of the original Whitworth BSW and BSF, and ISO metric thread forms and, you will see that they are much more refined than the American thread forms. It is annoying, however, to have to use yet another spanner type while working on your Rover. There is some comfort in this, the metric bolt (setscrew) could well be stronger than the US ones of similar size.

Recently, I purchased a quantity of 5/16" UNF setscrews and they were as soft as mild steel. I took them back and was given the same dimension setscrews from the Unbrako range. The setscrews that were soft, came in packaging marked 'PROC'. Now I have to use an Allen key as well as spanners!

Good luck with your metric conversion. A fan does not need removing too often.

My father was a member of the Institute of Mechanical Engineers and he read to me one day, from their magazine, that the British motor industry was changing over to UNF and UNC thread forms. My father's comment, and I think he was on the high side of being right, "That spells the end of the British motor industry!"

Regards,

Mike A.