IanPatterson Posted June 20, 2018 Report Share Posted June 20, 2018 Just about to start installing a Revotec Cooling fan on my TR4A. I am looking at where exactly I fit the fan controller on the bottom hose. My concern is that it appears to be positioned "on the bend" so as to have access to the controller temperature screw. (see attached photo). Does anyone have a photo of exactly where they fitted the controller on the bottom hose? Many thanks, Ian Quote Link to post Share on other sites
TR NIALL Posted June 20, 2018 Report Share Posted June 20, 2018 Ian,I don’t think folks are using that supplied Controler as they seem unreliable most are using a Stainless Steel Pipe with Stat Switch installed. Quote Link to post Share on other sites
peejay4A Posted June 20, 2018 Report Share Posted June 20, 2018 I use the Revotec stat. Its a bit inaccessible but once set it has been no trouble for years. Quote Link to post Share on other sites
ianhoward Posted June 20, 2018 Report Share Posted June 20, 2018 I have one fitted to the top hose on my 5... No issues after a good number of years use... Â Cheers Ian Quote Link to post Share on other sites
IanPatterson Posted June 20, 2018 Author Report Share Posted June 20, 2018 TR Nail : can you expand a bit on "Stainless Steel Pipe with Stat Switch". i.e. where from? Many thanks Ian Quote Link to post Share on other sites
TR NIALL Posted June 20, 2018 Report Share Posted June 20, 2018 (edited) Sorry Ian I see you have a TR4/4a im not sure that Pipe is available for that model. Edited June 21, 2018 by TR NIALL Quote Link to post Share on other sites
IanPatterson Posted June 20, 2018 Author Report Share Posted June 20, 2018 Thanks anyway. Sorry about the typo. Ian Quote Link to post Share on other sites
Malbaby Posted June 20, 2018 Report Share Posted June 20, 2018 As the top hose can be 10 deg hotter than the bottom....temp controllers or thermostats should be at the top of the cooling system, Quote Link to post Share on other sites
peejay4A Posted June 21, 2018 Report Share Posted June 21, 2018 What is the logic behind that please? Quote Link to post Share on other sites
ianc Posted June 21, 2018 Report Share Posted June 21, 2018 Revington has stainless steel tube with boss for thermostat - 130039SST. I installed one in 2000. Ian Cornish Quote Link to post Share on other sites
Agrace Posted June 21, 2018 Report Share Posted June 21, 2018 Hi Ian  You're right, the controller doesn't fit right in. I've just fitted one. I cut the equivalent length of the controller pipe off the top of the existing downpipe. You then have exactly the right space to fit in the controller pipe and connection. You are effective substituting the new controller pipe for a bit of the existing downpipe.  Hope that makes sense.  Regards Andrew Quote Link to post Share on other sites
IanPatterson Posted June 21, 2018 Author Report Share Posted June 21, 2018 Andrew, can you send a pic? Thanks Quote Link to post Share on other sites
Agrace Posted June 21, 2018 Report Share Posted June 21, 2018 I'll see what I can do. Quote Link to post Share on other sites
Malbaby Posted June 21, 2018 Report Share Posted June 21, 2018 The hottest part of the radiator is at the top where the water is pumped directly from the engine. By the time the water has travelled down the radiator to the bottom hose it is cooler. If you want an accurate temperature measurement, must be at the top. Quote Link to post Share on other sites
peejay4A Posted June 22, 2018 Report Share Posted June 22, 2018 Which is why a thermostat in the lower part would be set lower and still operate. Why is that worse than putting it at the hot part? Sorry to labour it but I dont see the benefit. Quote Link to post Share on other sites
Andy Moltu Posted June 22, 2018 Report Share Posted June 22, 2018 It probably matters little if the stat is in the top or bottom of the rad beyond the tempersture range being different. Â The case for the top being that it is more sensitive to a rising engine temp, the case for the lower in the rad or return being that it is better damped from fluctuations in the water temp. Quote Link to post Share on other sites
RobH Posted June 22, 2018 Report Share Posted June 22, 2018 One way of looking at it - its the thermostat that is intended to maintain the engine temperature. The cooling system should have excess cooling capacity such that the thermostat does not need to be wide open all the time but modulates the water flow as required to maintain normal temperature. Most of the time the forward air-stream is sufficient to ensure that the water being returned from the radiator is suitably cooled but when stopped in traffic, fan assistance is required to give the necessary cooling capacity. It would appear then that the correct place for the switch is in the return path to the engine..... Quote Link to post Share on other sites
stillp Posted June 22, 2018 Report Share Posted June 22, 2018 Rob, that assumes the water is circulating - what if the thermostat has failed closed? Â Then again, if the coolant level is low, the top hose might be empty so a thermostat there will be cold. Â Pete Quote Link to post Share on other sites
RobH Posted June 22, 2018 Report Share Posted June 22, 2018 (edited) Well you don't design the system to work under fault conditions I suppose. If there's no circulation or not enough water in the system the fan won't help will it ? In fact if the top hose is empty there's no point in putting the sensor there anyway. Edited June 22, 2018 by RobH Quote Link to post Share on other sites
Agrace Posted June 22, 2018 Report Share Posted June 22, 2018 Sorry, can't figure out how to attach photos. Quote Link to post Share on other sites
Agrace Posted June 22, 2018 Report Share Posted June 22, 2018 Aha. Quote Link to post Share on other sites
Agrace Posted June 22, 2018 Report Share Posted June 22, 2018 Another Quote Link to post Share on other sites
IanPatterson Posted June 23, 2018 Author Report Share Posted June 23, 2018 Andrew, thank you. So you have attached it towards the bottom of the hose. Presumably easier to fix but a bit more fiddly to adjust ? Ian Quote Link to post Share on other sites
peejay4A Posted June 23, 2018 Report Share Posted June 23, 2018 Same arranngement as mine. I used a small mirror to adjust it, maybe twice and it has been left alone since. Quote Link to post Share on other sites
Agrace Posted June 24, 2018 Report Share Posted June 24, 2018 Hi Ian Correct. However I angled the controller towards the radiator so that you can (just) see and access the adjustment. As it happens, no adjustment was neccessary. Quote Link to post Share on other sites
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