had17462 Posted January 10 Report Share Posted January 10 Hi all just putting a rebuilt engine 6cylinder onto the chassis ,it hasn’t got the fan extension or fan attached and usually just fit an electric one but as I have the bits can I just fit them or should it have been balanced with the engine rebuild either way what’s the opinion on which way to go regards Nick Quote Link to post Share on other sites
Trumpy Posted January 11 Report Share Posted January 11 Unless you are looking for originality I would go electric, much more efficient and better cooling . Especially at lower engine rpm , when stuck in traffic etc . With a thermostat it will trip on and off as required and can be adjusted to the required engine temperature. Quote Link to post Share on other sites
Andy Moltu Posted January 11 Report Share Posted January 11 For ultimate reliability the mechanical fan works and more than adequate if your radiator is fine The electric fan is more efficient as it is only needed when moving slowly/stationary. But the after market fans are simply not as reliable as the ones manufacturers fit to modern cars. Likewise the fan switches but they can be overridden with a simple switch. Quote Link to post Share on other sites
trchris Posted January 11 Report Share Posted January 11 I wouldn’t refit and go electric however as Andy has said the cheap ones are not worth fitting there are some good kits available Chris Quote Link to post Share on other sites
TRier Posted January 11 Report Share Posted January 11 Electric for me, I would go with either Kenlowe or Spal, both are quality, around a long time and used extensively in motorsport. Having a manual override switch is a very good policy and simple to do, costs little. In terms of difference to balance if you had the rotating parts balanced I would say yes eliminating the fan extension would likely make a difference if it was balanced with the extension on. But was it? If you are thinking about as supplied by Triumph then it wouldn't have been balanced as a full rotating assembly anyway. Quote Link to post Share on other sites
Nigel Triumph Posted January 11 Report Share Posted January 11 +1 Kenmore or Spal have worked reliably on my Triumphs, and as stated, electric fans are more efficient. Nigel Quote Link to post Share on other sites
RobH Posted January 11 Report Share Posted January 11 (edited) 3 hours ago, Andy Moltu said: For ultimate reliability the mechanical fan works Not 100% reliable - my '3A metal fan fractured one blade, presumably from fatigue. The resulting 3 1/4 bladed item did nothing for engine smoothness ! Since the mechanical fan works best when you don't need it but poorly when you do (at idle in traffic) , I took it off and fitted an electric one. Edited January 11 by RobH Quote Link to post Share on other sites
Z320 Posted January 11 Report Share Posted January 11 The solid fan is ultimative relaible, while electric is one more possible failture (thermostat, fuse, cable, ot the fan itself). I use a BMW 1602 plastic fan on my TR4A with a DIY shroud to get a better effectivity Ciao, Marco Quote Link to post Share on other sites
Bfg Posted January 11 Report Share Posted January 11 I'm with the mechanical fan fraternity, and endorse Marco's suggestion of using a moulded plastic fan, with a shroud around it, as being best. I hadn't fitted a shroud, and I use a TR6 seven-blade fan (which bolted straight on to the four cylinder engine), although I did have a fan extension lathe-turned from aluminium to achieve a much better balance and for less weight hanging off the end of the crankshaft. Quote Link to post Share on other sites
Lebro Posted January 11 Report Share Posted January 11 Can of worms has been opened ! many for electric, and many against them. Personaly I am in the electic fan camp. Have had a Revotec fan fitted since 2013, with an "Otter" thermostat switch. + override switch. Just what you need when comming to a standstill following a fast motorway session. Bob Quote Link to post Share on other sites
Harbottle Posted January 11 Report Share Posted January 11 5 minutes ago, Lebro said: Can of worms has been opened ! many for electric, and many against them. Personaly I am in the electic fan camp. Have had a Revotec fan fitted since 2013, with an "Otter" thermostat switch. + override switch. Just what you need when comming to a standstill following a fast motorway session. Bob X1 Quote Link to post Share on other sites
tim hunt Posted January 11 Report Share Posted January 11 4 hours ago, Andy Moltu said: For ultimate reliability the mechanical fan works and more than adequate if your radiator is fine The electric fan is more efficient as it is only needed when moving slowly/stationary. But the after market fans are simply not as reliable as the ones manufacturers fit to modern cars. Likewise the fan switches but they can be overridden with a simple switch. I cannot agree on poor reliability of after market fans Andy - at least not based on my experience. I bought a complete kit for my 4A second hand for £17 over 40 years ago and the motor is still going strong. A few years later I was lucky enough to spot another complete Kenlowe kit suitable for my car at a car boot. The vendor had no idea what he had hence I got it for £3!!. I keep the motor in the boot as a spare just in case and this second kit furnished a replacement capillary sensor when the original one failed, the only item to give up the ghost on 40+ years. Tim Quote Link to post Share on other sites
TRier Posted January 11 Report Share Posted January 11 4 hours ago, RobH said: Not 100% reliable - my '3A metal fan fractured one blade, presumably from fatigue. The resulting 3 1/4 bladed item did nothing for engine smoothness ! Since the mechanical fan works best when you don't need it but poorly when you do (at idle in traffic) , I took it off and fitted an electric one. Rob has pointed out the nub of it, reliability aside, the mechanical fan is brilliant when it’s needed least and close to useless when it’s really needed. Nowadays we’re faced with a lot more traffic and stop start than when these purely mechanical fans were the preferred solution. Niall Quote Link to post Share on other sites
Spit_2.5PI Posted January 11 Report Share Posted January 11 With reliability/fault-tolerance in mind I used two smaller fans (XJ6/XJ40 Air-con from memory) with independent wiring/fusing/relays. In nearly 20 years it hasn't been a problem. I would only say that the underbonnet temperature rises significantly in slow/stationary traffic when the fan only runs for say 20 seconds every few minutes. One day I will modify the system so the fans run slowly when the temperature at the back of the engine bay rises. This is the advantage of a mechanical fan - it's always moving the air. Cheers, Richard Quote Link to post Share on other sites
Andy Moltu Posted January 11 Report Share Posted January 11 I didn't say electric fans were unreliable but ultimately less so than the mechanical ones. (No mechanical fans on my Triumphs) The thermostatic switches don't last as long as they should. Capillary stats as used to supplied with Kenlow fans and older central heating boilers are far more reliable than the other types. The early TR mechanical fans are pretty feeble compared to the 6 pots. So a back up fan might be of benefit when stationary in hot weather or if the rad is past it's best. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 11 Report Share Posted January 11 5 hours ago, Lebro said: Can of worms has been opened ! many for electric, and many against them. Personaly I am in the electic fan camp. Have had a Revotec fan fitted since 2013, with an "Otter" thermostat switch. + override switch. Just what you need when comming to a standstill following a fast motorway session. Bob We are in the realms of the question I remember being asked many times as a seller of parts for these cars. “I just bought a TR what’s your opinion of the best modifications I can do to improve it?” Simple A pair of decent halogen headlamps and an electric fan. “Thank you sir that will be £40.00 less your NSF discount, if you are a member.” Quote Link to post Share on other sites
michaelfinnis Posted January 11 Report Share Posted January 11 7 hours ago, TRier said: Rob has pointed out the nub of it, reliability aside, the mechanical fan is brilliant when it’s needed least and close to useless when it’s really needed. Nowadays we’re faced with a lot more traffic and stop start than when these purely mechanical fans were the preferred solution. Niall Granted the mechanical fan absorbs power when the car is moving at speed and a fan is not really required, but it is not useless when needed and will provide adequate airflow to cool the engine when idling. These things ran perfectly ok with the factory set up back in the day. Mike. Quote Link to post Share on other sites
had17462 Posted January 11 Author Report Share Posted January 11 Thx for all the replies Nick Quote Link to post Share on other sites
Z320 Posted January 12 Report Share Posted January 12 (edited) Hi, in my opionin with the (fast) moving car air is automaticly pressed through the rad and the fan spins „empty“ without the need of any power. Imagine you run downhil withe a bicycle and anyway step on the pedals. To safe power with an electric fan is a wish, told by herarsay and on good believe. I know, this thought is new for a number of people. Ciao, Marco Edited January 12 by Z320 Quote Link to post Share on other sites
Z320 Posted January 12 Report Share Posted January 12 Btw I had my BMW fan spinning on my 1,500 Watt lathe some years ago with its mx. speed of 4,000 revs - without any problem, of cause with a windstorm in my little workshop Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 12 Report Share Posted January 12 (edited) 1 hour ago, Z320 said: Btw I had my BMW fan spinning on my 1,500 Watt lathe some years ago with its mx. speed of 4,000 revs - without any problem, of cause with a windstorm in my little workshop Does the BMW engine that the fan comes from originally have a viscous coupling between the fan and the engine drive? Is the fan originally mounted on the crankshaft or an idler or the water pump? I have often thought the addition of a cooling fan viscous coupling would benefit a TR with a mechanical fan installed. TR 7 and late Spitfire had it as standard and 6 cyl Triumph engines had them when fitted to post 1975 2500cc saloon cars. There are dozens of different ones out there fitted-on moderns that have N-S engine installation. Land Rover and Jaguar being obvious users. Edited January 12 by BlueTR3A-5EKT Quote Link to post Share on other sites
Steve Morris Posted January 12 Report Share Posted January 12 Surely a big advantage of the electric fan is quicker warm up, hence less wear. Quote Link to post Share on other sites
RobH Posted January 12 Report Share Posted January 12 11 minutes ago, Steve Morris said: Surely a big advantage of the electric fan is quicker warm up, hence less wear. No. Before the engine is fully warm, the thermostat is closed so no water is circulating through the radiator and the fan does next-to-nothing then. Besides, quickest warm-up is by driving the car rather than standing it at idle, so there is air-flow through the rad whether or not the fan is operating. Quote Link to post Share on other sites
Xmas6 Posted January 12 Report Share Posted January 12 Hi all - I used an electric fan from a Vectra (I think) with the switch soldered into the bottom of the radiator. I fabricated a bracket to mount it to the radiator using 6 mm diameter rod and flat bar. The car is still undergoing the rebuild but I’ve had it running and the fan comes on and off as required and seems to work well. Just another avenue if anyone wants to think about it. Cheers Neil Quote Link to post Share on other sites
Z320 Posted January 12 Report Share Posted January 12 (edited) 1 hour ago, Steve Morris said: Surely a big advantage of the electric fan is quicker warm up, hence less wear. It seems there is no "reason" poor enough to ague for an electric fan, even wrong ones are pretty welcome Edited January 12 by Z320 Quote Link to post Share on other sites
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