brian-nz Posted January 8, 2014 Report Share Posted January 8, 2014 (edited) Hi All I know there has been previous discussion about electric fans but wanted a bit more advice. Last weekend did a trip of about 150k (one way). Car went fine with temperature normal however when we stopped at the destination and had to wait in a queue for about 10 minutes the car boiled. So I am now investigating an electric fan which will be in front of the radiator and be a secondary one for above such occassions. Most people seem to have gone to either 10" or 12" ones, but I have seen advertised a smaller 7" blade one.(dimensions 210mm x 210mm x 65mm. Would this be sufficient or would it be too small to do the job. Also can the fan be installed without removing to front apron - would make life easier if it could. Regards Brian Edited January 8, 2014 by brian-nz Quote Link to post Share on other sites
Guest Posted January 8, 2014 Report Share Posted January 8, 2014 it's all about the displacement of air. A 7" can do the trick, but it depends on the shape / angle of the blades. Check the datasheet of the fan and compare it with the from (e.g.) a 10" Kenlow or Pacet. Pacet's data sheet: http://www.pacet.co.uk/clubfanpacets.php Menno Quote Link to post Share on other sites
vivdownunder Posted January 8, 2014 Report Share Posted January 8, 2014 Hi Brian, Probably have to remove the grille to check access for a TR3, but I think a 7" diam fan is a bit small and would suggest a 10" diam if you can squeeze it in. At least it's easier than a TR2 with the TR3 cutout in the top of the chute. Try and mount it off the vertical side rails of the radiator if you can. Fixings that go through the core aren't ideal. It will need a dedicated fuse and depending on whether your car is pos or neg earth, check that it rotates the correct way before re-installing the grille. Being supplementary, it might be easier to just operate it with a push-pull switch rather than go to the trouble of installing a sensor in the system. Regards, Viv Quote Link to post Share on other sites
BrianC Posted January 8, 2014 Report Share Posted January 8, 2014 I have an 11" Pacet blower fan plus plastic (TR6 or Spitfire) crankshaft mounted fan. Sensor for electric fan is in the steel bottom hose joining section. Car has done 25,000 miles since fitting and although the electric fan rarely comes on except in heavy traffic, it is an engine saver when it is needed. Quote Link to post Share on other sites
Dave Larnder Posted January 8, 2014 Report Share Posted January 8, 2014 Brian I have a 10¨suction fan behind the radiator, but now that I have installed the air duct behind the grille and a hot climate thermostat, the engine gets up to temperature in about 1 km, but never goes over that so the fan doesn´t do much these days, but roll on the Spanish summer and I will probably need it to switch in, but I normally do it manually before it gets to the set temperature. Dave Quote Link to post Share on other sites
Lebro Posted January 8, 2014 Report Share Posted January 8, 2014 Back in the 1970's I found that after a good blast on a fast road, to suddenly sitting in traffic the car would boil, I eventualy fitted a home made fan using a wiper motor stripped of it's gearbox, with a TR3 type Smiths heater fan connected to it (just stuff I had around at the time) As a secondary fan it did the trick. I had to switch it on manually when temperature would rise, & it stopped boiling. I'm not suggesting that you make one, but my fan was probably less than 7" dia, with a less powerfull motor that current fans come with, so I'm sure your 7" one will do the trick -as long as you keep the mechanical fan as well. Bob. Quote Link to post Share on other sites
Andrew Smith Posted January 8, 2014 Report Share Posted January 8, 2014 (edited) Also can the fan be installed without removing to front apron - would make life easier if it could. On what car Brian - 2, 3 or 3A? Edit: Just seen the TR3 tag, so they are useful after alll! - but left my reply in place for others who may be interested. If the 3A, yes it can be fitted with the apron in place and the 13" Kenlowe sits nicely on the front inner apron lip. I also kept the mechanical fan as a back-up, but fitted a tropical 6-blade one and with it fitted the Kenlowe rarely comes on other than in heavy stop-start traffic. Cheers Andrew Edited January 8, 2014 by Andrew Smith Quote Link to post Share on other sites
RogerH Posted January 8, 2014 Report Share Posted January 8, 2014 Hi Folks, I am amused at this thread - tell me to bu99er off if you wish as I have a windy up window car The mechanical fan is really there for when the car isn't moving forward at any appreciable speed or travelling excessively fast. As most of the posters have stated that the car boils over when standing then the mech fan isn't doing its job - so why have it. When running at normal speeds the mech fan is using up valuable HP - so why have it. Remove the mech fan, fit a puller fan (more efficient) and sit back and wait for the crank to snap. Roger Quote Link to post Share on other sites
Andrew Smith Posted January 8, 2014 Report Share Posted January 8, 2014 Roger, You may well have modern windy-up windows but you have the same engine old boy. I keep the mechanical fan as a back-up if the Kenlowe goes on strike - it does happen, ask Duncan Jolly about when the Kenlowe on his TR5 packed up at Goodwood when his son Gregg was driving and no mechanical fan - Gregg had to get the 5 back to Lincs............. Cheers Andrew Quote Link to post Share on other sites
Guest Posted January 8, 2014 Report Share Posted January 8, 2014 (edited) Addition to my first post: Menno Edited January 8, 2014 by Menno van Rij 2 Quote Link to post Share on other sites
RogerH Posted January 8, 2014 Report Share Posted January 8, 2014 Hi Andrew, Indeed you are quite right but how much built in redundancy can you carry. Perhaps two eleccy fans - a pusher and a puller Roger Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 8, 2014 Report Share Posted January 8, 2014 Andrew does TRK have a radiator duct fitted now? The cardboard duct, as we all know, is critical to get all the air into the radiator rather than round it on the TR3A. Roger I agree the mechanical fan is a redundant lump that saps power, makes a noise and might pull air through the rad if at the right speed when the car is stopped. Go electric Brian. I am sure you can pickup a simple electric fan from a wrecked rice burner. Maybe Try one of these NZ suppliers for new? http://www.pro-wholesale.co.nz/radiator-fan-electric-cooling-fan/ OR http://www.a1radiators.net.nz/products/performance_products/electric_fans They do gobble the amps though so my alternator comes in useful. My own TR3 runs quite happily in all UK environments including crawling round the M25 past Heathrow on a Friday evening mid summer. I too have a thermostatic switch in the bottom hose. It is a Moss Revotec kit. To retain the starting handle drive bolt I had to hack a bit of plastic off the fan shroud. Simple with a hack saw and pair of side cutters. I photo'd the mod and sent it to Moss so they knew the tasks involved if anyone else wanted to keep the starting handle. I also wired in a simple manual overide switch, as I fear these thermostatic things giving up the ghost at a critical point. Cheers Peter W Quote Link to post Share on other sites
Don Elliott Posted January 9, 2014 Report Share Posted January 9, 2014 Don't forget the possibility that if you eliminate the mechanical fan - you risk up-setting the harmonic vibrations and you could end up with a broken crankshaft (and maybe a blown engine as well). That's why I have a 12" Kenlowe pusher in front of the radiator and still have the mechanical fan on the front end of the crankshaft. I've had no issues with it like this for 23 years and 113,000 miles. I only turn it on in traffic when I see the temperature rise. It come back down to normal in a half a minute. The 12" fan is mounted high enough on the front of the radiator to permit me to still use the hand crank if I need to. Quote Link to post Share on other sites
RogerH Posted January 9, 2014 Report Share Posted January 9, 2014 OK you die hards. If you refuse to get rid of the mech fan why not improve it I'm sure it would be possible to fit a shroud on the rear of the rad to partially enclose the mech fan. I appreciate that the mech fan isn;t in the same place for all the TR's due to engine mount collapse, fore/aft position etc but I'm sure it is posible, And could look quite neat. Roger Quote Link to post Share on other sites
Andrew Smith Posted January 9, 2014 Report Share Posted January 9, 2014 Peter - yes, have had the rad ducting fitted for a many years. Roger - what about airflow to the carbs..........? Cheers Andrew Quote Link to post Share on other sites
RogerH Posted January 9, 2014 Report Share Posted January 9, 2014 Hi Andrew, surely you don't want warm/hot rad air for the carbs. There's always plenty of air in the engine bay!! Roger Quote Link to post Share on other sites
Guest Posted January 9, 2014 Report Share Posted January 9, 2014 (edited) Hi Andrew, surely you don't want warm/hot rad air for the carbs. There's always plenty of air in the engine bay!! Roger Sadly I don't have a pic of a solution I've seen a few years ago. A guy with a 3A had the airduct installed and he was worried about cold air going to the carbs. So he cut a round hole in the RH part of the duct, and attached a flexible house through the hole, leading to the front carb. Thus, when driving, cold air would be forced towards the carbs. Don't know if it's a proper solution tbh. Later Triumphs had a cold air box with two smaller flexible hoses leading from the front edge of the rad to the air box. Menno Edited January 9, 2014 by Menno van Rij 2 Quote Link to post Share on other sites
MilesA Posted January 9, 2014 Report Share Posted January 9, 2014 Menno I think that Tom (Fireman) installed a hose in the side of of his aluminium duct to feed air to the carbs. From personal experience, I agree that installing the often missing duct makes a real difference so it seems a bit counter intuitive to then reduce the amount of air being forced through the radiator by installing a hole in the duct. As the duct was an original (if hurriedly implemented) part of the 3A design, I suspect absence of an air feed from the duct would not affect a car running on original carbs. However, my car has Webers which are a bit air-greedy so rather than reduce duct effectiveness, I am thinking of installing a 3" hose directed at the carbs which scoops air from a position next to the radiator, under the platform at the bottom of the front grill (sorry cannot for the moment think of the correct term!). No doubt I will be advised that the benefit is marginal but it's an otherwise harmless mod' so indulge me. Miles Quote Link to post Share on other sites
Guest ntc Posted January 9, 2014 Report Share Posted January 9, 2014 Miles Extractor ducting 4 " and spigot from B&Q will do the job Quote Link to post Share on other sites
BrianC Posted January 9, 2014 Report Share Posted January 9, 2014 Chris Glasbey's TR3A has Webers and cold air ducting through the grill (from Racetorations): Quote Link to post Share on other sites
stuart Posted January 9, 2014 Report Share Posted January 9, 2014 (edited) You dont want the air ducting too low down i.e. down below the rad or front panel as a deep puddle would see water sucked in. Neils suggestion is a cheap and easy solution and done in the cardboard duct wont take that much flow away from the rad but will feed cold air to the carbs a treat.. Stuart. Edited January 9, 2014 by stuart Quote Link to post Share on other sites
Dick Posted January 9, 2014 Report Share Posted January 9, 2014 Fit an electric fan by all means. I have one but only because I removed the crank fan to fit a damper. These cars don't boil unless there is something wrong....certainly on standardish cars. I had a similar problem some years ago after building up an engine out of three others. Did everything....new rad., leccy fan, water pump, hoses, thermostat etc to no avail. In the finish I swapped the water pump housing for a known good one.....the result was as different as night and day. I am running 10:1 ish compression with a fast road cam and even after thrashing it for 3 or 4 hours on a hot day and then crawling in traffic the leccy fan rarely cuts in and there is virtually no after boil when the engine is switched off. I am not suggesting that this is the fault on yours, although it might be, but as frustrating as it is, I would try to tackle the problem not the affect You might do something that does compensate for the problem but the fault will still be there to catch you out. Quote Link to post Share on other sites
MilesA Posted January 9, 2014 Report Share Posted January 9, 2014 Thanks chaps. Hope you find a solution Brian - I know this temperature business can be very irritating. Miles Quote Link to post Share on other sites
brian-nz Posted January 10, 2014 Author Report Share Posted January 10, 2014 Hi All Thanks for all the advice. I am leaning towards a 10" fan at the front of the radiator - a 7" may end up being too small. I will have it on a manual on / off switch and only use when required as I always keep an eye on the temperature gauge. I will also re flush the radiator as it was sitting around for about 12 months prior to installing. The water pump and thermostat are new. I like the idea of Rogers in manufacturing a shroud to partially cover the radiator so may investigate this further. I do not expect this to be a regular occurrance but better to be safe than sorry Regards Brian Quote Link to post Share on other sites
Guest Posted January 10, 2014 Report Share Posted January 10, 2014 Be sure to add a relay and separate fuse (in line) when you install the fan. Some fans use a lot of current during the start. Menno Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.