cwillst Posted September 1, 2021 Report Share Posted September 1, 2021 I have what is claimed to be a MKIV Spitfire 1972. I have learnt over 5 years of ownership that the parts used range wildly across most of the Spitfire models. Mainly MKIV and 1500 models. The engine is a 1300cc dolomite block. The water pump bearing has started to rattle so it will soon fail. Looking at part diagrams on Rimmers the pump looks suspiciously like a mk3 part no GWP200. It has the metal fixed fan and a grease nipple that I have seen mentioned on a prior post. Could you experts please confirm just what is installed? Any advice on replacement? The wider diameter pulley version GWP128 is what should be in place. Will fan holes line up if I get that pump and would the pulley still line up? It looks like the GWP128 part is easier to obtain but that might give me a problem with parts being exchanged. Thanks for any advice Link to comment Share on other sites More sharing options...
NonMember Posted September 1, 2021 Report Share Posted September 1, 2021 That's definitely an early type pump with a Mk3 fan. The good news is that early pumps are serviceable, so it may not actually need to be replaced. If you fit the later type pump then I'm not sure whether the fan will fit. Certainly the very late pump takes a viscous fan, which is a different mounting. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 1, 2021 Report Share Posted September 1, 2021 The important thing is that the pulleys line up so that the belt is not twisted. The larger pulley will simply spin faster, so it's not the size but the protrusion of the pulley that matters. The GWP200 fits both Herald and Spitfire, the GWP 128 has the larger pulley but I think in the same plane as the other, but something like the GWP 201, for GT6 and Vitesse, won't be suitable. That red band is just paint around the 'lip' and not a spacer, as I first thought. Link to comment Share on other sites More sharing options...
DanMi Posted September 1, 2021 Report Share Posted September 1, 2021 actually Colin, a larger pulley would turn slower the pulley size was changed because the mk4 has a larger crank pulley, so the water pump was altered to match that. All fans will fit, so no problem there. I believe the greaseable ones were only fitted to mk1-2. the later type is easily available but quality may be hit and miss and there is no exchange but you would need a longer belt. The one you have can be rebuilt with new seal and bearing Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 1, 2021 Report Share Posted September 1, 2021 10 minutes ago, DanMi said: actually Colin, a larger pulley would turn slower the pulley size was changed because the mk4 has a larger crank pulley, so the water pump was altered to match that Yes, you're right!! For some reason I was thinking of a larger pulley spinning more quickly but that's just the outer edge travelling further, which takes longer to go round, not less... apologies! Link to comment Share on other sites More sharing options...
cwillst Posted September 1, 2021 Author Report Share Posted September 1, 2021 Thank you all for the feedback. I will call EP Services who I see recommended on these pages. Any other pump supplier recommended? I will now try to remove the pump. I was due to replace the antifreeze so the timing is OK. Link to comment Share on other sites More sharing options...
johny Posted September 1, 2021 Report Share Posted September 1, 2021 Its definitely the water pump is it? I say that because its unusual for the bearings to fail because the seal normally starts to leak years beforehand and then the complete unit is replaced rather than going to the trouble of replacing the seal. You could remove the fan belt and run the engine to confirm the rattle is no longer present... Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 1, 2021 Report Share Posted September 1, 2021 dry creaky fan belts can be very decieving in the squeak and clatter brigade rub dip stick on the sides or a puff of talc quietens for a while do mind the fan Pete Link to comment Share on other sites More sharing options...
cwillst Posted September 2, 2021 Author Report Share Posted September 2, 2021 It is the water pump. We used a large screwdriver to listen with. It became noisy enroute to the Shalbourne classic car show. A friend who was a professional mechanic also listened and was sure of the problem. Didn't even have to put an ear close to the screwdriver. There is a bigger movement in the bearing than normal. I was surprised that the car made it home without a leak. I will try your suggestion anyway, it is all good experience. Again thanks for the help Link to comment Share on other sites More sharing options...
johny Posted September 2, 2021 Report Share Posted September 2, 2021 Could just be bad luck on the water pump bearing although of course excessive belt tightness can accelerate wear. I run mine with little tension as theres not much load on it and you'd hear it slipping... Link to comment Share on other sites More sharing options...
cwillst Posted November 21, 2021 Author Report Share Posted November 21, 2021 Just an update. It was the water pump. I got it off, sent to EP Services who refurbished it within a week. Their service was excellent and they guarantee it for the life of the product. All is quiet again, well quieter! Thanks for the advice from all. 1 Link to comment Share on other sites More sharing options...
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