angelfj Posted January 24, 2009 Report Share Posted January 24, 2009 (edited) original post here I finally had a chance to photograph the fan extensions today. The following two photos show three different fan extensions and respective dimensions. We had used the middle cast iron extension which did not provide adequate clearance between the fan and radiator. The correct extension, nearly 3/4-inch shorter is shown on the right. In addition, whil looking for the correct extension, we found an aluminum one which is shown on the left. We have not yet verified what car this came from or in fact that it was a TR. (could it be a Morgan???) Edited January 24, 2009 by angelfj Quote Link to post Share on other sites
Chris59 Posted December 6, 2009 Report Share Posted December 6, 2009 Hello Frank, I don't think the left extension came from a Morgan, as the Morgans with TR4 engine haven't the fan on the crankshaft, but on the water pump pulley. Cheers, Chris. Quote Link to post Share on other sites
Dave Larnder Posted December 6, 2009 Report Share Posted December 6, 2009 original post here I finally had a chance to photograph the fan extensions today. The following two photos show three different fan extensions and respective dimensions. We had used the middle cast iron extension which did not provide adequate clearance between the fan and radiator. The correct extension, nearly 3/4-inch shorter is shown on the right. In addition, whil looking for the correct extension, we found an aluminum one which is shown on the left. We have not yet verified what car this came from or in fact that it was a TR. (could it be a Morgan???) Frank Chuck the whole lot out and go for a narrow belt conversion and an electric SUCKING fan and an alternator if you want to.. Many snapped crankshafts have been attributed to the extension and standard fan. Dave Quote Link to post Share on other sites
Dave Larnder Posted December 6, 2009 Report Share Posted December 6, 2009 original post here I finally had a chance to photograph the fan extensions today. The following two photos show three different fan extensions and respective dimensions. We had used the middle cast iron extension which did not provide adequate clearance between the fan and radiator. The correct extension, nearly 3/4-inch shorter is shown on the right. In addition, whil looking for the correct extension, we found an aluminum one which is shown on the left. We have not yet verified what car this came from or in fact that it was a TR. (could it be a Morgan???) Frank Chuck the whole lot out and go for a narrow belt conversion and an electric SUCKING fan and an alternator if you want to.. Many snapped crankshafts have been attributed to the extension and standard fan. Dave Quote Link to post Share on other sites
Don Elliott Posted December 6, 2009 Report Share Posted December 6, 2009 Dave - Most of the "stories" about broken crankshafts which I have read about were not related to the hub extension and the fan directly. The cranks all broke after the hub and fan had been removed !!! I say "stories" because I have not heard any reports from people with our 4-cylinder TRactor engines with no issues where the owner had a long record of driving with the hub extension and fan removed. That's half the reason I left my hub and fan installed - and then installed a pusher 12" Kenlowe fan in front of the radiator in my 1958 TR3A. The other half of the reason is so I don't get docked points by a concours judge for not having the origonal hub extension and fan. Quote Link to post Share on other sites
Mychael Posted December 6, 2009 Report Share Posted December 6, 2009 Dave - Most of the "stories" about broken crankshafts which I have read about were not related to the hub extension and the fan directly. The cranks all broke after the hub and fan had been removed !!! I say "stories" because I have not heard any reports from people with our 4-cylinder TRactor engines with no issues where the owner had a long record of driving with the hub extension and fan removed. That's half the reason I left my hub and fan installed - and then installed a pusher 12" Kenlowe fan in front of the radiator in my 1958 TR3A. The other half of the reason is so I don't get docked points by a concours judge for not having the original hub extension and fan. On my first TR which broke it's crank, I had retained the extension but removed the fan when I went to an electric one. Mychael Quote Link to post Share on other sites
RogerH Posted December 6, 2009 Report Share Posted December 6, 2009 Hi Don, the 'extension' and crank breakage saga has not been researched at all (as far as I know). However the nature of the common break occuring at the 4th big end journal is caused by a simple fatigue fracture probably caused by flexing of the crank (I have a long winded theory that is quite convincing - honest)and machining marks left behind during manufacture. It is not a shear fracture or a torsional fracture. Whether the extension is on or off would not realisticly affect what is going on so far back. I don;t know for certain if there have been any failures with the extension fitted - people tend not to report on these matters so all the info is lost. My car has done over 100,000miles over the last 11 years with no extension/fan and is going fine (I wish I hadn't said that ). I believe TR2's had a history of crank breakage in the early years and these would have had the extension in place (I may have dreamt this one!!) The crank has broken in places other than the 4th big-end but quite rare. Perhaps the Register should conduct a survey - Model, Mileage, Exention on/off, type of driving etc. Without proper research it will always be a thing of mystery Roger Quote Link to post Share on other sites
Don Elliott Posted December 7, 2009 Report Share Posted December 7, 2009 I have over 182,000 miles on my 1958 TR3A from new and I have always kept the hub extension and fan as it was when I bought it brand new. The S-T designers and engineers were not stupid. They did a lot of great and innovative engineering over the years from 1952 to 1980. I don't want to take mine off when it doesn't need to come off - so it will stay on for another 52 years. By then, I'll be 124 years old. I'll get back to you then with the latest up-date. Quote Link to post Share on other sites
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