Rob19 Posted February 12, 2011 Report Share Posted February 12, 2011 I bought a 4A last autumn from a TR specialist dealer and am slowly going through it to put right some of the mechanical shortcomings I subsequently discovered (how it passed an MoT with the handbrake working the way it is I'll never know). The car has an electric cooling fan which has a mind of its own and only works automatically when the car is stationary. A friend has run his 4A for the last 10 or so years with the original mechanical cooling fan without any problems and I'm considering returning my car to original mechanical cooling. I'd be interested in comments on the advantages (or otherwise) of electric cooling - apart from the obvious lack of drag on the engine and better cooling in traffic - and the effectiveness of mechanical cooling. Presumably the latter works OK otherwise Triumph wouldn't have sold so many of these cars in the original configuration? And.....................if any one has recently changed to an electric fan and is wondering what to do with the old mechanical bits I could be interested in them. Thanks in anticipation............... Rob19 Quote Link to post Share on other sites
peejay4A Posted February 12, 2011 Report Share Posted February 12, 2011 (edited) Rob, When I finally finish my build I'll be using an electric fan. That's much to do with going for a narrow fan belt conversion and the unserviceability of my original mechanical fan. Have a look at the workshop manual to see just how complicated the balancing arrangements are on the original "windmill". When you say your electric fan only works when the car is stationary I'd say that was normal behaviour for a thermostatically controlled fan - it was how the e-fan worked on my TR6 for sure. When you're moving there should be plenty of airflow through the radiator so the fan shouldn't need to run unless the ambient air temperature is quite high - unusual in the UK, or if you're in very heavy traffic. It's the power loss due to turning a big lump of a mechanical fan all the time when moving that you get back by having an electric one. Claims vary as to how much power benefit there is to be had. Edited February 12, 2011 by peejay4A Quote Link to post Share on other sites
Rob19 Posted February 12, 2011 Author Report Share Posted February 12, 2011 Thanks Peejay for the prompt response. I should have said that the fan doesn't switch automatically when the temp goes to max when driving - I have to use the manual override switch; at idle it cuts in and out as you'd expect. That could be a problem with the existing adjustable fan 'stat (probe in the top return pipe) and I've got a 'switch in the pipe' set up to fit sometime or I guess it could be the main 'stat. I suspect the cooling system needs more attention generally (flushing and check of the stat type) because the car has done less than 4K miles since rebuild between '90 & '96 so has most likely stood for long periods between use. It just occurred to me that the original system seems simpler but I need to check out the balancing arrangements following your comments. Rgds, Rob19 Quote Link to post Share on other sites
Norfolkjohn Posted February 12, 2011 Report Share Posted February 12, 2011 Provided you have (or can get) all the original bits, and are happy to stick with the wide belt / dynamo, I don't see why reverting to the original mechanical fan should be a problem. Perhaps I'm missing a point somewhere (wouldn't be the first time ) but the instructions in page 1-130 of the workshop manual seem simple enough. The important thing would be to make sure you correctly position the fan hub and the balancer (basically a horse-shoe shaped washer), but there is a 1/16 location hole provided to ensure correct orientation. I have retained the original fan on my 4A but also had an electric fan fitted to the front of the rad as a back up. I have yet to switch this on and have not had any overheating problems. Quote Link to post Share on other sites
ianc Posted February 12, 2011 Report Share Posted February 12, 2011 I have been told that modern unleaded fuel tends to make the engine run hotter, and I think that the radiator on a TR4 is only just adequate (the smaller-engined TR2 never had problems). It's important to ensure that the ducting in front of the radiator is in place and that the gaps either side are blocked-off (see my article in Section B18 of the Technicalities CD), for the duct - quite stupidly - is wider than the radiator (perhaps designed for the wider TR4A radiator?)! I removed my original fan in 1970 and have used an electric fan ever since. Because the old Kenlowe arrangement of a bulb inserted into the top hose always wept once the seating had been disturbed a few times, nowadys I have the control exercised by a thermostatic switch in the metal tube in the return circuit from the radiator to the water pump, with an over-ride on the dash. I converted to thin belt some years ago, and was amazed how much more room there appeared to be at the front of the engine! And the spare belt is so much easier to store and to fit - the original belt was very much from the tractor era and adequate for a Vanguard which would scarcely ever exceed 4,000 rpm!. Ian Cornish Quote Link to post Share on other sites
RogerH Posted February 12, 2011 Report Share Posted February 12, 2011 (edited) Hi Rob, in theory (and practice usually) the electric fans are better than the mechanical fan. They only operate when needed so again in theory you use less petrol. If you have an electric fan fitted at present then you should have the thin belt and pulleys. These are better than the chuncky belt - easier to fit and should last longer. Why is your e-fan causing problems? If it comes on when the car is stationary (ignition off!!!!) then it is wired direct to the Batt +12v. It comes on because when you stop hot water convects up to the sensor (top rad pipe) - this is normal. Your sensor is connected to an adjustable thermostat. This allows the fan to come on at the temp you require when stuck in traffic. You say it doesn't come on when moving - it shouldn't. As stated previously the airflow through the rad should sort this. However you mention moving and MAX temp on gauge. If this is so then you have problems in your engine stopping the cooling water from flowing correctly. OR your gauge is duff The mechanical fan wont fix this. If possible fit a different temp gauge. Make sure all the wiring is OK (it does appear to be doing the right things) Try and establish that the cooling system waterflow is OK. Does the heater work - it should get hot (quite a few people say the 4/4A are hopeless - no they are not. It should get hot). If it doesn't then that may reinforce the poor circulation idea. best of luck. Report back when sorted Roger Edited February 14, 2011 by RogerH Quote Link to post Share on other sites
Badfrog Posted February 12, 2011 Report Share Posted February 12, 2011 Hi, I have the same experience as Ian. The thin belt is really a plus. Years ago a comparative test was done on a Peugeot 404 : original mech ventilator with big belt versus electric fan with small belt. The removal of the original set-up (very similar to that of a TR4) produced a surprising gain of 5.7 BHP. So I am definitely "electric" and I use an inline (82°C) switch system as described by Ian. Badfrog Quote Link to post Share on other sites
Rob19 Posted February 12, 2011 Author Report Share Posted February 12, 2011 Many thanks guys - a lot of useful stuff here. Just for clarification the e-fan only works automatically when the engine is at idle so I guess its the convection scenario RogH mentions. When the car is under way the temp just continues to rise and will rise to max unless I manually switch on the e-fan. The gauge seems OK as it responds to the presumed drop in temp when the fan runs. And no its still running on the wide belt although fitted with an e-fan. Presume it would be a good idea to change this? I suspect as RogH says that there is some silting up of the cooling circuit so that will be the first thing to try to resolve. I then have the in-line switch mod(which Badfrog and Ian mention)to fit, as a further 'improvement'. But first I need to sort the handbrake out so I can park on any suface which isn't dead flat!!! Will see what progress I can make over the next couple of weeks and report back. Thanks again, Rob19. Quote Link to post Share on other sites
RogerH Posted February 12, 2011 Report Share Posted February 12, 2011 Hi Rob, the 4A handbrake is not that special. Have a look at the whole system (cables, levers, pins etc) give them a good grease/oil. Make sure the shoes are in good order. If still no joy then there are two mod's you can do to transform it. 1....On the handbrake lever itself it is possible to move the linkage that holds the two cables closer to the handle pivot - this will double the effect. 2....On the hand brake levers on the back plate. The cable attachment holes can be extended another 1" - thus giving an apprx increase of 25%. If you do a search for handbrake you should find some past info on this. Roger Quote Link to post Share on other sites
Rob19 Posted February 12, 2011 Author Report Share Posted February 12, 2011 Rog - many thanks for the heads-up on the 4A handbrake threads. More very useful stuff. Seems many people have been down this road before! Rgds, Rob. Quote Link to post Share on other sites
JJC Posted February 13, 2011 Report Share Posted February 13, 2011 Just one further thought, I've just had the rad on the TR2 recored. The chap that did it advised against using the Kenlowe plastic strip fasteners that pass through the rad core. The original rads have widely spaced tubes and it worked just fine. Modern cores have very closely spaced tubes and the worry is that heat cycling might cause failure. Anyway, that was their advice. So I made up some brackets to dispense with the plastic strips. Very easy and cost about £5 for two cars. The radiator chap also confirmed my experience which is when moving you don't need a fan at all. So if you do there might be something wrong. When stuck in traffic on a hot day I nearly always need the fan. Good luck. JJC Quote Link to post Share on other sites
Andrew Smith Posted February 13, 2011 Report Share Posted February 13, 2011 Just one further thought, I've just had the rad on the TR2 recored. The chap that did it advised against using the Kenlowe plastic strip fasteners that pass through the rad core... Both my 3A and 6 have Kenlowe front mounted blower fans with the plastic strip fasteners and both have operated without any problems with this securing method. Both TRs still have their original fans in place (although the 3A is fitted with a 6-blade tropical fan - highly recommended!) as a back-up against the Kenlowe failing - ask Duncan Jolly about the Kenlowe failing on his 5 at Goodwood - suffice it to say the original fan is also now fitted! Cheers Andrew Quote Link to post Share on other sites
Menno van Rij Posted February 13, 2011 Report Share Posted February 13, 2011 (edited) When the car is under way the temp just continues to rise and will rise to max unless I manually switch on the e-fan. The gauge seems OK as it responds to the presumed drop in temp when the fan runs. Perhaps I overlooked important information you or a fellow forum member already mentioned... but reading this, I would think that -when driving- the needle moves all the way 'upwards' on the dial until it points at the MAX (i.e. highest possible) temperature. And that it only will come 'down' when using the elec. fan. The only way to lower the position of the needle is by starting the fan? I'm sure most of us here will agree with me that the normal operation tempurature when running the car under normal conditions is about halfway up! Remember, these gauges aren't exactly rocket science, but I would like to stress out that this needs further investigation before you turn to the elec. fan! And before you take all things apart: how's your fuel gauge working? I remember vaguely (and correct me if I'm wrong!) that the TR4 has a volt stabilisor. I had one in my Spitfire years ago and when the stabilisor failed, the both gauges (fuel and temp.) started working erratically. Lately, my Saab's gauges had the same trouble and that turned out to be an earth cable faillure. Second: the next suspect (remember! when the temp is constantly rising) is the water pump. Some years ago, there was a bunch of cr*ppy water pumps around. Menno Menno Edited February 13, 2011 by Menno van Rij Quote Link to post Share on other sites
67_gt6 Posted February 14, 2011 Report Share Posted February 14, 2011 do you actually have symptoms of over heating? the temp sender may be faulty, five quid part. andy Quote Link to post Share on other sites
MadMarx Posted February 14, 2011 Report Share Posted February 14, 2011 (edited) Perhaps I overlooked important information you or a fellow forum member already mentioned... but reading this, I would think that -when driving- the needle moves all the way 'upwards' on the dial until it points at the MAX (i.e. highest possible) temperature. And that it only will come 'down' when using the elec. fan. The only way to lower the position of the needle is by starting the fan?... That is the part which is disturbing me. Normal running = normal temperatures. The fan should only come on when the car is standing still or pulling very hard. There must be something very wrong on that machine. Cheers Chris (who is running a silent fan that is switched on the radiator bottom) Edited February 14, 2011 by MadMarx Quote Link to post Share on other sites
88V8 Posted February 14, 2011 Report Share Posted February 14, 2011 When the car is under way the temp just continues to rise and will rise to max unless I manually switch on the e-fan Engine gets hotter as you go faster? Sounds like a blocked radiator. To check the rad, get the engine warm, switch off. With a plant mister, spray the rad fins then idle the engine and watch it dry. The areas that dry slowly have no circulation. Nothing wrong with the Kenlowe/bulb arrangement, and on my cars they don't leak and never have. The seal widgets eventually become brittle, but new ones are available by post from Kenlowe. The Kenlowe is adjustable for temp, and I fail to see that a non-adjustable switch is any sort of improvement. Uh oh, had this discussion before.... Ivor Quote Link to post Share on other sites
randall977 Posted February 14, 2011 Report Share Posted February 14, 2011 I was going to fit an electric fan but then I like the look of the original so stuck with it. I didn't consider the extra 5 degrees [citation needed] due to modern fuels so wonder if I made the right decision. My resto isn't finished yet so I have not been able to test the car, now would be a good time to upgrade... btw - I have rebuilt the engine so it should be cooling as efficiently as it's going to... Quote Link to post Share on other sites
ianc Posted February 14, 2011 Report Share Posted February 14, 2011 If you have re-built the engine, it will be tight for some time, so will generate more heat! Ian Cornish Quote Link to post Share on other sites
67_gt6 Posted February 14, 2011 Report Share Posted February 14, 2011 (edited) chaps let's slow down here. i haven't read anything to suggest the car is actually overheating. the sender on a 4A is electric, they go wrong. mine was bust when I bought my 4A, I was "overheating" for weeks (gauge in red, but no actual symptoms). flushed block several times, new radiator - no change. eventually ran the car up to temp with the cap off the radiator, put a thermo probe (from a cheap multimeter) into the neck of the rad at the point when the gauge was going into the red, only to discover that the temp was only 82 degrees C. changed sender - problem fixed, but a series of time consuming and expensive leaps to conclusions before I got there. Rob's symptoms all suggest a knackered sender to me. If we ignore what he is seeing on the gauge and examine what is happening with the fan, the fan may well be behaving normally and is confirming that everything is in order except the sender: - the fan (which is thermo switched) never comes on when the car is moving. neither it should - the air flow is enough to keep the temp below the thermo switch activation point. - the fan comes on at idle. so it should - the temp will eventually creep up enough to activate the thermo switch. Andy Edited February 14, 2011 by 67_gt6 Quote Link to post Share on other sites
RogerH Posted February 14, 2011 Report Share Posted February 14, 2011 ...good one Andy. The sender could well be iffy, along with the gauge and/or the voltage regulator/stabilizer. Roger Quote Link to post Share on other sites
dykins Posted February 14, 2011 Report Share Posted February 14, 2011 I'm beginning to think that I'm the only person left on the planet whose TR4 still has a mechanical fan which has never, ever overheated. Well, at least not in the 14 years that I've owned it. Regards Peter Quote Link to post Share on other sites
Rob19 Posted February 14, 2011 Author Report Share Posted February 14, 2011 Hmmmm.....plenty of food for thought here Chaps. Many thanks. My assumption that the e-fan should work when the car is moving is simply based on the fact that I've been more used to cars with mechanical fans, which are of course continually running and therefore give the impression that the fan alone is responsible for cooling rather than simply the air being forced through the radiator by the movement of the car. The latter is obvious I guess when you think about it To summarize then: The engine should derive sufficient cooling from airflow through the rad when on the move. Assuming it is, thats the reason the e-fan doesn't cut in. The e-fan will cut in when the car is stationary because of lack of any other airflow through the rad and this tends to indicate that the probe is sensing correctly. This also suggests that there is some flow through the cooling system to activate the probe. Whether there is unhindered flow around the system could do with further investigation/pre-cautionary flush. The fact that the fan doesn't run when the temp gauge reaches max when the car is on the move is indicative of a duff temp sender or gauge or voltage stabiliser, because the e-fan thermostat probe seems to be sensing as it should and would switch on the e-fan at that sort of temp. The fact that the fuel gauge gives very strange readings suggests that the voltage stabiliser is a good place to look. So a cheap initial stab at a solution would be temp sender and voltage stabiliser. That seems easy-ish. Where's the most likely place to look for the location of the voltage stabiliser? Thanks to all - particularly Andy for the lo-cost option! I'll let you know what happens. Rob. Quote Link to post Share on other sites
Alec Pringle Posted February 14, 2011 Report Share Posted February 14, 2011 Hi Peter, don't worry about it, if the engine and cooling system are in good order then it won't overheat. I have a neighbour who hails from Utah, often looks at the Forum and chuckles. He doesn't understand the 'need' for an electric fan. Reminisced about spending Independence Day 1970, touring Death Valley as it seemed as good a place as any after two years of flying gunships in 'Nam . . . . Evidently the temperature didn't fall below 100F at night, nudged 130F in the day, his well thrashed TR4 never missed a beat or used any water over a couple of weeks touring plus the run there and back from Salt Lake City. He had thought about a 6-bladed fan, just never got round to it. Cheers, Alec Quote Link to post Share on other sites
RogerH Posted February 14, 2011 Report Share Posted February 14, 2011 Hi Rob, Drivers/Righthand footwell at top of kick panel. Roger Quote Link to post Share on other sites
RogerH Posted February 14, 2011 Report Share Posted February 14, 2011 Hi Peter, There will be two of us with Mech fans when I get the 4 on the road in a couple of months(ish). Roger Quote Link to post Share on other sites
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