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The water pump in my TR4 engined Morgan began to leak at the end of last year and I've removed it today, intending to send it to EP Services for a recon.

However, the removed pump appears to be an 'uprated' 6 vane version and although it's always seemed to perform OK I recall reading about the risk of cavitation with the uprated pumps. Somewhere amongst the last 40 years of 'stuff' I've got an original leaky pump, so the question is whether I try to find it, and ditch the more modern version. I don't even know whether EP Services would tackle the modern pump if asked, but I'll speak to them tomorrow. What do people think?

Secondly I've only removed the pump body and not the housing, two studs came out as studs and so I'm not sure whether to leave the housing alone or whether to remove it and refit with a new gasket. Getting at any of it is a bit of a pig because I can't get the radiator out with out quite a bit of further dismantling, so it's just moved forwards a couple of inches and the electric fan dropped about 6 inches to get the pulley off. On the one hand access is tight, but on the other hand I wouldn't want to do the job again in a hurry... Do people normally remove and refit the housing or leave it in place?

Serves me right I suppose for having a kit car with a wooden chassis 

Thanks

Malcolm

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Personally, I have not needed to touch the housing - just changed the pump when it was leaking.

I can’t imagine why EP would recon the updated pump, the only difference is the impeller - I’d expect their work is concentrated on reconn’ing the bearing/seals and refitting whatever impeller it came with.

There has been plenty of discussion about the pros/cons of updated vs std. on this forum - I chose a std. one, dealers choice I guess.
.…. Andy 

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1 hour ago, Malcolm Tatton said:

The water pump in my TR4 engined Morgan began to leak at the end of last year and I've removed it today, intending to send it to EP Services for a recon.

However, the removed pump appears to be an 'uprated' 6 vane version and although it's always seemed to perform OK I recall reading about the risk of cavitation with the uprated pumps. Somewhere amongst the last 40 years of 'stuff' I've got an original leaky pump, so the question is whether I try to find it, and ditch the more modern version. I don't even know whether EP Services would tackle the modern pump if asked, but I'll speak to them tomorrow. What do people think?

Secondly I've only removed the pump body and not the housing, two studs came out as studs and so I'm not sure whether to leave the housing alone or whether to remove it and refit with a new gasket. Getting at any of it is a bit of a pig because I can't get the radiator out with out quite a bit of further dismantling, so it's just moved forwards a couple of inches and the electric fan dropped about 6 inches to get the pulley off. On the one hand access is tight, but on the other hand I wouldn't want to do the job again in a hurry... Do people normally remove and refit the housing or leave it in place?

Serves me right I suppose for having a kit car with a wooden chassis 

Thanks

Malcolm

Malcolm - I think EPS may be able to refurbish your repro 6 vane pump - it will all depend whether the shaft and bearing sizes are the same as an OE one.

The next question is whether you want to do that because I've heard, like you, that these uprated extra vane pumps actually pump worse than standard ones due to cavitation - I suppose that EPS might be able to swap the impeller for an original one but again that will depend on shaft diameters and bore sizes.

In my opinion you might be better off finding your original pump for reconditioning but if you are still struggling, I do have some spare ones already reconditioned by EPS .

As for the pump housing on the block, that should be OK to leave as is if you haven't disturbed it but just double check the leak wasn't coming from this joint rather than the pump!

Cheers Rich

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In my opinion the standard one is good enought,

all about „uprated“ is solving not existing problems.

Btw I have never seen any cavitation on any impeller.

Best you can do with a TR4 engine is to do what Triumph did with the TR4A:

kick the bellows thermostat in the bin, fit a wax thermostat and reduce the bypass on the pump housing down to 8-8.5 mm,

not smaller, please.

P1110096-b.JPG.39a75ec809470d5c9c31ea5b4b9c36ca.JPG

Edited by Z320
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Go and have a dig in the garage Malcolm and get your original reconditioned, they work fine.

Stuart.

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Did see a video on here once of the flow through the water pump - someone had replaced the top hose with a transparent hose.

Standard pump has ample capacity to service the radiator.  Flow is not the rate limiting step so uprating the water pump is more appropriately termed increased excess capcity.

If you run as modern wax stat (rather than a bellows, make sure you reduce the diameter of the bipass to avoid too much water bipassing the rad (the bellows effectively closed the bipass when the original stat opened) and circulating around the block without passing through the radiator.

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30 minutes ago, Andy Moltu said:

Did see a video on here once of the flow through the water pump - someone had replaced the top hose with a transparent hose.

Standard pump has ample capacity to service the radiator.  Flow is not the rate limiting step so uprating the water pump is more appropriately termed increased excess capcity.

If you run as modern wax stat (rather than a bellows, make sure you reduce the diameter of the bipass to avoid too much water bipassing the rad (the bellows effectively closed the bipass when the original stat opened) and circulating around the block without passing through the radiator.

 

 

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This are my videos on my YouTube accout.

The first one shows the MASSIV flow by the standard water pump,

the second one shows there is no need to worry any air in the system because the pump is a MONSTER,

keeping the air already in the flow while the engine is only  idling and the thermostat closed.

There is no need to worry at all (as long you don’t drive with PVC hoses!!)

Ciao, Marco

Edited by Z320
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13 hours ago, Andy Moltu said:

(the bellows effectively closed the bipass when the original stat opened)

This is the common saying and hope BUT not at all true.

If you compare you see the bellows thermostat is a horrible plug forcing the flow in the bypass,

and the sleeve has a wide gap to the thermostat housing and can’t close the bypass at all.

My measurement showed me with the bellows thermostat with sleeve there is never less than 30% of the flow going the bypass.

I‘m still so angry about the stories I‘ve been told years ago about the „winder sleeved bellows“ and about the money I spend to buy one.

This could be the reason why the Triumph engineers made a modification from the TR4 to the 4A?

post-13222-0-52553800-1523820131_thumb.jpg

post-13222-0-80922800-1528409377_thumb.jpg

post-13222-0-53955200-1528409387_thumb.jpg

Edited by Z320
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Because the whole system is oversized.

edit:

And do I remember correctly: you use a 86°C bellows and the indicator is "nailed" on your gauge (earlier post)?

Than you need the bypass anyway more than with the 71°C summer thermostat, recommended by the (German) workshop manual.

Anyway: I recommend not to limit the bypass to much (not smaller than 8 mm diameter),

even on a 20°C summer day it needed to have as much as possible flow thought this old cast iron boiler under the bonnet.

8 - 8.5 mm bypass in combination with a wax thermostet fully opened (hot) works to have nearly 100% flow through the rad.

Edited by Z320
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  • 4 weeks later...

Just to follow up and say thanks for the replies really, but in the end I fitted a reconditioned OE type pump that was supplied by Rich. Haven't been able to test it on a long journey yet, but am happier with the old type pump.

Thanks again

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