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    Raise the header tank

    Does anyone know the best way to raise the stag header tank, or if there is a specific bracket that can be used to raise the bottle. I've been advised that the bottle should be raised to sit just above the water pump level.

    #2
    I'm saying nothing other than use the search box.
    I only do what the voices in my wife’s head tell me to do!

    Comment


      #3
      If you are talking about the original plastic bottle that sits down low at the side of the radiator then it is not a header tank but an expansion bottle. Raising it higher so the water level sits above the water pump will make no difference as the pipe that connects it to the radiator goes some way down into the radiator which could allow an air pocket in the top of the radiator if used as a header tank. Who ever advised you to raise the bottle doesn't understand how the original system (if this is what you have) works. They have probably heard that the water pump on the stag sits high up and any drop in coolant level potentially exposes the pump so it no longer circulates the coolant. - which is true.

      To mitigate against this risk some, and I emphasise some, people fit a header tank and plumb this into the cooling system, usually via - but not always - connections to the bottom hose (feed) and the top of the radiator (via the filler bung) (air bleed). (Note that is only one example - other options are available). The actual tank used varies from plastic tanks obtained at scrap yards (or eBay) from cars as varied as Ford Sierras, Mercedes and Volvos, to more period looking metal ones mainly from Land rover Defenders or they get an "off the shelf kit" from one of the Stag Accessory suppliers - two of which are Stagwebber and E J Ward. The off the shelf kit is a more expensive route but you do get a complete kit which should just bolt on. Using one from another vehicle will mean time spent sourcing hoses, connectors and making brackets fit - not hard and quite cheap to do but does require that you know and understand what you are doing, a kit as mentioned should come and "just bolt on" and require little skill..

      Personally I have the original system that works well for me, as do many other Stag owners.

      It is worth noting that a header tank while providing an extra reserve or head of water will not cure any deficiencies in the cooling system or cure overheating. If your system has a leak, it will still leak. If it overheats, it will still overheat. The one worthwhile advantage in my book is that the tank can be fitted with a low water level switch to sound an alarm or switch on a warning light if the coolant level starts to fall - giving an early warning of a problem. An other advantage is said to be that it keeps a positive head of water in the system and, if plumbed in correctly, self bleeds preventing any air locks.

      Roger

      So many cars, so little time!

      Comment


        #4
        Originally posted by Jeff View Post
        I'm saying nothing other than use the search box.
        or if you are short of time read the Complete Works of Shakespeare


        (Explanation for the sake of clarity of my comment ....... the subject of header tanks has been discussed many, many times on the forum so there are many, many threads on the topic. Some of which are useful and informative, some less so. It would take many hours to read through them all !)

        Roger
        So many cars, so little time!

        Comment


          #5
          Originally posted by marshman View Post

          or if you are short of time read the Complete Works of Shakespeare


          (Explanation for the sake of clarity of my comment ....... the subject of header tanks has been discussed many, many times on the forum so there are many, many threads on the topic. Some of which are useful and informative, some less so. It would take many hours to read through them all !)

          Roger

          I only do what the voices in my wife’s head tell me to do!

          Comment


            #6
            Originally posted by marshman View Post
            If you are talking about the original plastic bottle that sits down low at the side of the radiator then it is not a header tank but an expansion bottle. Raising it higher so the water level sits above the water pump will make no difference as the pipe that connects it to the radiator goes some way down into the radiator which could allow an air pocket in the top of the radiator if used as a header tank. Who ever advised you to raise the bottle doesn't understand how the original system (if this is what you have) works. They have probably heard that the water pump on the stag sits high up and any drop in coolant level potentially exposes the pump so it no longer circulates the coolant. - which is true.

            To mitigate against this risk some, and I emphasise some, people fit a header tank and plumb this into the cooling system, usually via - but not always - connections to the bottom hose (feed) and the top of the radiator (via the filler bung) (air bleed). (Note that is only one example - other options are available). The actual tank used varies from plastic tanks obtained at scrap yards (or eBay) from cars as varied as Ford Sierras, Mercedes and Volvos, to more period looking metal ones mainly from Land rover Defenders or they get an "off the shelf kit" from one of the Stag Accessory suppliers - two of which are Stagwebber and E J Ward. The off the shelf kit is a more expensive route but you do get a complete kit which should just bolt on. Using one from another vehicle will mean time spent sourcing hoses, connectors and making brackets fit - not hard and quite cheap to do but does require that you know and understand what you are doing, a kit as mentioned should come and "just bolt on" and require little skill..

            Personally I have the original system that works well for me, as do many other Stag owners.

            It is worth noting that a header tank while providing an extra reserve or head of water will not cure any deficiencies in the cooling system or cure overheating. If your system has a leak, it will still leak. If it overheats, it will still overheat. The one worthwhile advantage in my book is that the tank can be fitted with a low water level switch to sound an alarm or switch on a warning light if the coolant level starts to fall - giving an early warning of a problem. An other advantage is said to be that it keeps a positive head of water in the system and, if plumbed in correctly, self bleeds preventing any air locks.

            Roger
            Very well put.
            Dave
            1974 Mk2, ZF Auto, 3.45 Diff, Datsun Driveshafts. Stag owner/maintainer since 1989.

            Comment


              #7
              Originally posted by marshman View Post
              If you are talking about the original plastic bottle that sits down low at the side of the radiator then it is not a header tank but an expansion bottle. Raising it higher so the water level sits above the water pump will make no difference as the pipe that connects it to the radiator goes some way down into the radiator
              It doesn't on my car, the return pipe from the expansion bottle goes no more than12mm into the top tank. The old one that I pulled out was that length as well.

              The cooling system on my car is completely original and works perfectly well, even on hot days and on rally stages.
              Mabel is a white 1972 Mk1˝, TV8, ZF 4HP-22 auto,
              2016 RBRR finisher. 400 mile C2C 21/22 April 2018!

              Comment


                #8
                the only benefit from raising the original overflow bottle is that as the system cools and water is sucked back into the rad, if the expansion bottle has been raised the water has not got to be sucked up as far, so the possible benefit of a less likely air leaking back into the rad

                Comment


                  #9
                  Originally posted by mole42 View Post

                  It doesn't on my car, the return pipe from the expansion bottle goes no more than12mm into the top tank. The old one that I pulled out was that length as well.

                  The cooling system on my car is completely original and works perfectly well, even on hot days and on rally stages.
                  Thanks for the info Richard, to be honest I wasn't exactly sure how far the tube went in , just knew it wasn't right at the top. The main point was (could have made it a bit clearer) that it is not an ideal connection point for a proper header tank as you will not get the benefit of fully "automatic" bleeding of all the air in the system, you would always be left with a reasonable pocket of air at the top of the radiator and probably the top section of the top hose as well unless you topped up through the bung in the radiator.

                  Good to hear that you still have an original setup and that it works well - especially as yours is your daily driver and part time rally car!. It verifies my point that a header tank is not a fix for any faults in the cooling system - be it leaks, blockages or any thing else.



                  Roger
                  Last edited by marshman; 12th September 2019, 13:47.
                  So many cars, so little time!

                  Comment


                    #10
                    I haven't read all the replies but there is a technical bulletin, with diagram, that I shared here out of Leyland Austrailia that says to raise the expansion bottle and do a few other things. Maybe for a Mk2
                    Sujit

                    Comment


                      #11
                      Hi All, sorry to hijack this thread. I wonder if anyone can point me in the right direction.....

                      I have fitted a stainless steel header tank sometime ago now, it works fine, but I would like to fit a coolant level sensor. Has any retro fitted one to a header tank? It is one of those that is specifically made for a stag but with no fitting for a sensor.

                      Thanks in advance for any help.

                      Neil

                      Comment


                        #12
                        You need one of these.
                        They fit from the outside. As you tighten the nut the rubber seal is compressed and you don’t need access to the inside of the tank.
                        I’ve had one on my header tank for several years.
                        HALJIA PP Low Pressure Side Mount Horizontal Water Level Sensor Liquid Level Sensing Float Switch Witch Wire Cable for Tank Pool https://www.amazon.co.uk/dp/B06VW88G5P/ref=cm_sw_r_cp_api_i_J1jFDbFRJPS7Z

                        Comment


                          #13
                          Originally posted by Phil S View Post
                          the only benefit from raising the original overflow bottle is that as the system cools and water is sucked back into the rad, if the expansion bottle has been raised the water has not got to be sucked up as far, so the possible benefit of a less likely air leaking back into the rad
                          Yea, if it was more than 32 feet below the rad! I do not understand all this hub-bub about header tanks over a recovery bottle. Fortunately physics works the same for everyone. I have yet to drive my car more than from the hauler to my garage so I do not know if the total system design capacity is sufficient or I have any issues. I know from my previous 6 LBCs, only the Morgan was insufficient in capacity. All the rest were simple defects.

                          Comment


                            #14
                            Originally posted by marshman View Post

                            or if you are short of time read the Complete works of Shakespeare
                            Roger
                            Please not William Shakespeare did not own a Stag !!!

                            Comment


                              #15
                              Originally posted by RobinLegin View Post

                              Please not William Shakespeare did not own a Stag !!!
                              Or did he?
                              Mabel is a white 1972 Mk1˝, TV8, ZF 4HP-22 auto,
                              2016 RBRR finisher. 400 mile C2C 21/22 April 2018!

                              Comment

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