d2alfa Posted June 7, 2022 Report Share Posted June 7, 2022 Hi, Has anyone fitted an expansion tank as a means of increasing the amount of water circulating? Which is the most appropriate tank to fir please? Thanks d2 Quote Link to post Share on other sites
stuart Posted June 7, 2022 Report Share Posted June 7, 2022 31 minutes ago, d2alfa said: Hi, Has anyone fitted an expansion tank as a means of increasing the amount of water circulating? Which is the most appropriate tank to fir please? Thanks d2 Yes fitted a few, I use the MGB brass one, site it up high on the inner wheel arch and fit a flat cap to the rad and a pressure cap to the expansion tank. Stuart. Quote Link to post Share on other sites
Z320 Posted June 8, 2022 Report Share Posted June 8, 2022 (edited) Hi David, do you still have the cooling problems from one year ago? Did you fit a wax thermostat, as it is original to a TR4A (with the correct water pump housing)? If you have a cooling problem you better solve it instead fitting a pressurised expansion container. Or do you only want a "nice" modification (no benefit in my opinion)? Ciao, Marco Edited June 8, 2022 by Z320 Quote Link to post Share on other sites
ianc Posted June 8, 2022 Report Share Posted June 8, 2022 See my article in TR Action 112 (February 1994), repeated in Section B18 of the Technicalities CD, in which I described how I had incorporated an header/expansion tank to my TR4's cooling system in 1993. I obtained a Triumph Dolomite brass tank from a scrapyard, and moved caps as described by Stuart. In my article I described other things which you can do to improve the effectiveness of the TR4's cooling system. Ian Cornish Quote Link to post Share on other sites
Andy Moltu Posted June 8, 2022 Report Share Posted June 8, 2022 The expansion tank won’t increase the amount of water circulating significantly. The water in the tank isn’t in circulation. What it will do is add more reserve capacity in case of loss and simplify filling. Quote Link to post Share on other sites
d2alfa Posted June 8, 2022 Author Report Share Posted June 8, 2022 Thanks for the advice. Your installation looks a very neat job Stuart. The wax thermostat was faulty and I have reverted to a standard 72 version Marco. I will look at the Technicalities CD Ian. Thanks all d2 Quote Link to post Share on other sites
Z320 Posted June 8, 2022 Report Share Posted June 8, 2022 David, with „standard 72 (deg Cel.)“ you mean a bellows thermostat? What is your problem with the cooling, please? Ciao, Marco Quote Link to post Share on other sites
Andy Moltu Posted June 9, 2022 Report Share Posted June 9, 2022 The role of the bellows stat is to restrict flow to the bipass hose when the stat is opened so the flow goes to the radiator. If you fit a "modern" stat to an engine that built for a bellows stat too much flow can continue to go via the bipass instead of the radiator. You need to sleeve down the bipass if you use a later stat so that only a small amount of flow goes throught the bipass and returns to the engine uncooled. Quote Link to post Share on other sites
RobH Posted June 9, 2022 Report Share Posted June 9, 2022 (edited) 54 minutes ago, Andy Moltu said: You need to sleeve down the bipass if you use a later stat Not sure this is a 4 or a 4A but I understood that the 4A already had a smaller bypass suitable for a modern thermostat? Also the original thermostat was not just a bellows type - it also had an additional sleeve to close off the bypass. An ordinary bellows 'stat won't do that. Edited June 9, 2022 by RobH Quote Link to post Share on other sites
Andy Moltu Posted June 9, 2022 Report Share Posted June 9, 2022 Over the years one or two have aqquired the wrong plumbing bits! Quote Link to post Share on other sites
stuart Posted June 9, 2022 Report Share Posted June 9, 2022 2 hours ago, RobH said: Not sure this is a 4 or a 4A but I understood that the 4A already had a smaller bypass suitable for a modern thermostat? Also the original thermostat was not just a bellows type - it also had an additional sleeve to close off the bypass. An ordinary bellows 'stat won't do that. Correct as proved by our friend Marco. Stuart. Quote Link to post Share on other sites
d2alfa Posted June 10, 2022 Author Report Share Posted June 10, 2022 Having looked around I am going to follow Stuart's design. I cannot see your pipework Stuart but assume that the top connection of the new header tank goes to the existing catch tank, and the bottom connection goes to the radiator. d2 Quote Link to post Share on other sites
Z320 Posted June 10, 2022 Report Share Posted June 10, 2022 Some days I‘m very tired…. and more and more I think about it’s better to be out of this forum Quote Link to post Share on other sites
Hamish Posted June 10, 2022 Report Share Posted June 10, 2022 1 hour ago, Z320 said: Some days I‘m very tired…. and more and more I think about it’s better to be out of this forum Don’t give up on the forum. Sometimes we just like to tinker and add bits. So long as there is no harm to the car as a result. Quote Link to post Share on other sites
stuart Posted June 10, 2022 Report Share Posted June 10, 2022 8 hours ago, d2alfa said: Having looked around I am going to follow Stuart's design. I cannot see your pipework Stuart but assume that the top connection of the new header tank goes to the existing catch tank, and the bottom connection goes to the radiator. d2 The bottom of the two connections on the tank goes to the original overflow pipe out of the radiator where there is now a flat non pressure cap. The smaller top pipe just under the pressure cap on the header tank is an overflow pipe and just goes down and is clipped to the chassis. Its a very simple system and doesnt take long to fit. Stuart. Quote Link to post Share on other sites
stuart Posted June 10, 2022 Report Share Posted June 10, 2022 7 hours ago, Z320 said: Some days I‘m very tired…. and more and more I think about it’s better to be out of this forum Dont give up Marco I need some support here Stuart. Quote Link to post Share on other sites
Motorsport Mickey Posted June 10, 2022 Report Share Posted June 10, 2022 I know how you feel Marco and especially when some posters feel that “ doing the wrong thing…righter ! “ will sort out their problem. We only have to check against our search box and we find a high percentage of questions raised have been covered before… sometimes in threads that are 7 or 8 pages long with 10 or 12 posts per page. ! All this info available, and often the original question answered comprehensively and with photos to show how it’s done. But… that’s how mere humans are, and many a poster here ( I for one) have reason to thank you for your postings and excellent articles. Please bear with us. Mick Richards Quote Link to post Share on other sites
Andy Moltu Posted June 10, 2022 Report Share Posted June 10, 2022 Another thing to check if you do the header tank mod is that the pipe that comes out of the rad (that normally goes to the overflow bottle) is sealed where it enters the radiator neck. Some are pressed in and may leak when exposed to rad pressure. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted June 10, 2022 Report Share Posted June 10, 2022 1 hour ago, Motorsport Mickey said: I know how you feel Marco and especially when some posters feel that “ doing the wrong thing…righter ! “ will sort out their problem. We only have to check against our search box and we find a high percentage of questions raised have been covered before… sometimes in threads that are 7 or 8 pages long with 10 or 12 posts per page. ! All this info available, and often the original question answered comprehensively and with photos to show how it’s done. But… that’s how mere humans are, and many a poster here ( I for one) have reason to thank you for your postings and excellent articles. Please bear with us. Mick Richards Let us not forget Hengist Pod who invented the square wheel so his bicycle should not roll back on hills ( Carry On ……..,something) Quote Link to post Share on other sites
Andy Moltu Posted June 10, 2022 Report Share Posted June 10, 2022 Let’s not overlook that we may have read and contributed to threads that have been covered before, others may not be aware of that. What’s new to some is repetition to others but that’s not a problem. The search facility is limited and not all are au fait with site searches via google. A new thread might reveal new thoughts and answers. Your idea of what’s right may not be the same as mine but that’s opinion. Quote Link to post Share on other sites
Malbaby Posted June 10, 2022 Report Share Posted June 10, 2022 12 hours ago, Z320 said: Some days I‘m very tired…. and more and more I think about it’s better to be out of this forum Marco....I always look forward to your sensible comments Quote Link to post Share on other sites
Tr4aJim Posted June 10, 2022 Report Share Posted June 10, 2022 You also have to make allowances for “vernacular” in the Search feature. I remember when I first joined this forum I tried to do a search for “adjusting hoods”, and couldn’t figure out why I was getting results about convertible tops! Jim Quote Link to post Share on other sites
ianc Posted June 11, 2022 Report Share Posted June 11, 2022 Adding to Andy's note about the overflow pipe from the radiator: When converting the system to use a header/expansion tank, remember that this tube will then be subject to the pressure within the cooling system, so the old, floppy length of rubber or plastic should be replaced with a tube capable of withstanding such a pressure, and it should be secured at each end with a suitable clip. The old overflow tube can be transferred to the tank's neck (upper) connection, where it is not subject to any coolant pressure. as it is just an overflow Ian Cornish Quote Link to post Share on other sites
Lebro Posted June 11, 2022 Report Share Posted June 11, 2022 +1 An alternative is to use an expansion bottle as per TR4, again ensuring the coonecting pipe is well sealed at the rad end, & goes to the bottom of the expansion bottle at the other. The rad cap must have the sprung loaded pressure relief seal, and a good seal on the top in order to suck coolant back into the rad when it all cools down. I use this system, & am able to keep the rad full to the brim. Bob Bob Quote Link to post Share on other sites
d2alfa Posted June 11, 2022 Author Report Share Posted June 11, 2022 Thanks all for your comments and advice. Referring to Marco's note. The car is a 4a and the engine was rebuilt two years ago and the timing and carbs were set up by a TR specialist garage. Last summer the engine ran very hot and I replaced the thermostat with a bellows type on the understanding that this would aid flow of the coolant; in fact it made matters worse. For a time I ran without a thermostat and all was well. This would have meant a longer time to get the engine up to operating temperature in the winter. I fitted a 72degree thermostat and all was well until the summer came and the engine is running hot again requiring the electric fan to run all the time. The plugs show that the mixture is on the rich side of normal; my understanding is that a weak mixture would increase the running temperature. Quote Link to post Share on other sites
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