A New Water Pump for a BMC 1.5

[Theo]

I decided to start a new topic with a more relevant title.

 

Got back to the boat this afternoon and collected the water pump from Taylor's Boatyard who received it for me while we were away.

 

All looks well apart from the fact that the 73mm diameter rotor is about 7mm thicker than the new one so it fits into a rather deeper cavity in the cylinder block. Here are some photos that show the difference.

 

I phoned Calcutt who told me that the new one would work OK but I thought that I would run it past the experts on here to take your opinions. I would have thought that the new one would have delivered a smaller volume at lower pressure.

 

What do you think?

 

Here are the links:

 

https://www.dropbox.com/s/a89t9t2s3khb85a/2014-11-27%2015.52.53.jpg?dl=0

 

https://www.dropbox.com/s/skmy2alxpm1krz2/2014-11-27%2015.53.33.jpg?dl=0

 

https://www.dropbox.com/s/h7l6tgspr9npenl/2014-11-27%2015.54.22.jpg?dl=0

 

https://www.dropbox.com/s/k7xzulye03qfy4b/2014-11-27%2015.54.41.jpg?dl=0

Edited November 27, 2014 by Theo

[RLWP]

Offer the pump up to the hole and see if it will go around. If it will, it's OK

 

Richard

[Theo]

Offer the pump up to the hole and see if it will go around. If it will, it's OK

 

Richard

Thanks, Richard.

 

BTW Do I need to use sealer on the gasket? Anything special or will water resistant grease do?

 

Nick

Edited November 27, 2014 by Theo

[RLWP]

Oooh, that's going to cause an argument

 

I prefer to put gaskets in dry, which works. I do this because some day, some poor mechanic may have to take the pump off again, and it could be me!

 

Richard

[Theo]

If dry works for you then it should work for me!

 

N

[Tony Brooks]

Although grease will help hold it in place while fitting and not stick the gasket to the pump or block.

[Theo]

Job done

 

Not leaking on a short test up to full engine temperature. Appears to drive the hot water around the central heating system so it would seem to be as efficient as the last one.

 

We are staying in Chester for the rest of the weekend so it will have it's full cruising test on Monday.

 

One problem that I had while fitting was that the casting has been changed. The old one had two short bolts and two long ones boting it to the cylinder block. The new one needs three short bolts and one long one. The long ones have a shank so I was unable simply to cut it shorter. Fortunately Tim, the blacksmith at Taylor's, was able to cut the bolt and extend the threads. I was quite surprised when he said that he had a UNF die that would fit. He took a while doing it, though. He fopund that it was a "proper bolt" and the die could not cut it so he had to heat treat it first and then "normalise" it. I think that normalising is a matter of slow cooling but he didn't go into detail.

 

N

[Troyboy]

Where are these water pumps being manufactured ? A thinner impellor and a different casting makes me wonder if this isn't for the Indian version of the BMC 1.5 .

[Dutchie]

I,m very interesting what the cooling will do on a hot summerday with higher outsidewatertemp.

the impeller of the new pump is really much smaller .

 

just had a look on my Worn down pump from 2 years ago , its the same as your broken one , i have also a look at my spare one (i bought 2 from asap with gaskets ) but this one is really the same with the old one .

 

my engine is a Thornycroft T90

Edited November 30, 2014 by Dutchie

[Theo]

I,m very interesting what the cooling will do on a hot summerday with higher outsidewatertemp.

the impeller of the new pump is really much smaller .

I am convinced that it will be OK. It is providing enough pressure/flow to drive the engine cooling water around my central heating system and the calorifier which is all plumbed with 15mm. There is much less resistance in the heat exchanger so the flow should be fine.

 

N

[Theo]

I,m very interesting what the cooling will do on a hot summerday with higher outsidewatertemp.

the impeller of the new pump is really much smaller .

 

 

 

I think that it has had a pretty good test now. I can't find any difference between the operation of the old pump and the new. We have just plugged up the Thames from Brentford to Reading and all has work well. No sign of any overheating.

 

N

[Dutchie]

Ok, Theo

Its good to know that this type of pump is working well on the BMC without overheating .

[Theo]

The other thing that I was interested to discover is that there seems to be no difference in its performance in driving water around the various circuits: Bathroom Radiator, Saloon Radiators, Calorifier.

 

N