| Author | Message | ||
     Martin Cutler Prolific User Username: martin Post Number: 35 Registered: 10-2004 |
Is changing the UK spec large fan pulley for the export smaller puller a hard job? More importantly, has anyone got one in Oz, or know where to get one? Marty | ||
| David Gore Moderator Username: david_gore Post Number: 394 Registered: 4-2003 |
Marty, Before you proceed further; have you considered the effect of changing the pulley size on coolant flow/radiator air flow given the environment and driving conditions for your vehicle? It is my understanding that normal practice is to fit the smaller pulleys to cars that spent most of their time in stop-start city driving to maximise coolant/air flow to prevent overheating. Cars used for long-distance/continuous driving were fitted with the larger pulleys to extend water pump life as the induced air flow through the radiator from the vehicle speed provided sufficient cooling. I suggest Lloyd Missen would have the best information for you but he does not use the internet so you will have to contact him direct [see Chassis Plate/Praeclarum]. | ||
| John Dare Prolific User Username: jgdare Post Number: 160 Registered: 12-2004 |
Hello Martin. Suggest you might like to also talk to John Vaswer who had a pulley locally made (in Sydney) for my R-type considering the air cond., an assessment of my location (Melbourne) including general driving conditions etc. The finished pulley displayed an "aircraft" standard of finish, almost becoming an "objet d'art", too "nice" to put in my car. But of course I did, and everything worked as planned; good air cond. and good overall engine temperature etc. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 551 Registered: 4-2003 |
Martin, I suggest that you contact Norman Geeson. The change is simple enough to carry out but is opening a can of worms. Norman wrote an exhaustive article on this for the RREC Bulletin just in the last weeks. Essentially, you need to change the fan and pulley, not just one or the other, or big problems may arise. Of course, the V-belt is smaller too. | ||
| Laurie Fox Experienced User Username: laurie_fox Post Number: 8 Registered: 6-2004 |
Martin There is a topic in this forum which you might like to look at -MK VI Overheating questions. | ||
| John Dare Grand Master Username: jgdare Post Number: 162 Registered: 12-2004 |
Martin. I omitted to mention that my R-type has a fan with one extra blade. I believe that all blades also have a slightly increased angle although it retains a general "stock standard" appearance. Not even the "experts" notice it until I draw their attention to it. Together with the wider grille vane angles, the car probably tends to run just a fraction on the cool side, however on a warm to hot ( eg 32c) day, I do not have to worry about any sign of overheating in any traffic situation with air.con. on etc. John V also fitted an auxilliary thermatic fan as a safeguard for any extreme circumstances that may arise and for those sometimes unavoidable, extended "idle" periods whilst stationary. | ||
| Martin Cutler Prolific User Username: martin Post Number: 36 Registered: 10-2004 |
Hi guys, Thanks for the info. Now that the hot days are over, I will probably not have to rely on the thermo fan as much. The inline filter in the top hose has not caught anything, so I think my system is pretty clean. My wifes modern Toyota failed last week, meaning she took the MG and I got to drive the Bentley to work. Every time I stopped in traffic, the temp went straight to 85, and I turned on the thermo fan which bought it back to 75, but I thought there must be a better way. I take on board the issue of the extra wear and tear on the water pump, however re angling the vanes on the fan sounds interesting! Has anyone played with the after market stainless fans available at speed shops? The original one is VERY heavy. Marty | ||
| Ashley James Unregistered guest Posted From: 80.229.46.15 |
Norman Geeson cc6@lineone.net will be able to supply a drawing of a smaller diameter pulley that uses the existing fanbelt. The early cars had the small pulley and, I think, a 16.5" Fan blade, then the fan was lengthened slightly and the larger pulley fitted. All the cars that were supplied to countries where overheating was experienced were fitted with, I think, a 17.25" and the smaller pulley. Over the same period, the number of radiator slats was reduced and they were rotated to increase airflow through the radiator. If you write to Norman I'm sure he will send you all the part numbers and information you need to decide what to do with your car. I have covered the basic details on my website www.kda132.com but it sounds as though the electric fan is taking care of the problem. | ||
| Martin Cutler Prolific User Username: martin Post Number: 37 Registered: 10-2004 |
Hi Ashley, Yes, the electric fan is working, but it does not solve the problem. Something I will look into in the long term I think. | ||
| Ashley James Unregistered guest Posted From: 80.229.46.15 |
Marti The fact that the fan is able to lower the temperature shows that it is solving the problem. It is increasing airflow through the radiator which is a primary requirement. What you have described is what happens on my BMW bike in traffic. The temp goes up, the fans switches in and pulls it down, then it stops and the process repeats. I took the high speed pulley off my car because it made the fan very noisy but I do have an electric one as well. I think that if you can keep the temp below 85 in traffic in hot weather with an electric fan, then you need not worry. |
