CageyH Posted April 26, 2019 Share Posted April 26, 2019 There are basically two circuits, as I have a PRRT. The heater bypass loop running anti clockwise and the main loop running clockwise when viewed from above with the radiator to the right hand side. There is always the header tank circuit as well, but as the flow is negligible, I am ignoring this. As I have the bypass loop always open (no thermostat in the original housing) there is always flow here. By putting the pump in the thermostat J hose, this should not create any issues as the return feed into the thermostat housing will still be open. Any reasons why I should not fit the pump in place of the J hose? Link to comment Share on other sites More sharing options...
rj Posted April 26, 2019 Author Share Posted April 26, 2019 I would be worried about the back pressure the bypass hose would cause at the head. Potentially this couuld reduce the flow in the whole engine.I would source a Ttee and move the bypass to the entry side of the external pump Link to comment Share on other sites More sharing options...
CageyH Posted April 26, 2019 Share Posted April 26, 2019 Or just fit the pump in the upper radiator hose? That will not disturb the coolant flow around the thermostat housing in any way. I am not sure that you will get back pressure in the tee at the thermostat, as I am sure that the mechanical pump will move more water when the engine is at 6k to 8k rpm, but I don’t want to risk it. Link to comment Share on other sites More sharing options...
CageyH Posted April 26, 2019 Share Posted April 26, 2019 If it is good enough for Lotus on the VHPD engine, surely it will work for me?http://mgf.ultimatemg.com/group2/coolant/ewp.htm Link to comment Share on other sites More sharing options...
CageyH Posted April 27, 2019 Share Posted April 27, 2019 To avoid any backflow/back pressure issues, the EWP80 is going to have to go in the top radiator hose. Anywhere else and I need to alter the plumbing, either the feed into the thermostat, or the take off for the header tank. Link to comment Share on other sites More sharing options...
rj Posted April 27, 2019 Author Share Posted April 27, 2019 That's how I see it.You could fit it on the exit of the water rail, but, and there always is one: I would rather "push" the water through the engine than "pull" it.The higher the pressure the higher the boiling point. If you have the inlet to the pump at the exit of the engine you'll reduce the pressure in the engine. Link to comment Share on other sites More sharing options...
CageyH Posted April 27, 2019 Share Posted April 27, 2019 What is a reliable way of blocking off the thermostat housing “T”? Link to comment Share on other sites More sharing options...
CageyH Posted April 27, 2019 Share Posted April 27, 2019 Looks like you can get blanking caps for this purpose, so I will go that route. Link to comment Share on other sites More sharing options...
rj Posted April 27, 2019 Author Share Posted April 27, 2019 There's a chance that I'll drop the engine in the car later today. Not sure I'll manage to fit the water pump, but if I can, I shall take a picture of the installation. Link to comment Share on other sites More sharing options...
CageyH Posted April 27, 2019 Share Posted April 27, 2019 That would be good, thanks. As long g as there is flow through the engine, unless there is pump cavitation then the pressure should remain the same if "pulled" or "pushed" through the engine as it is a closed loop. The only issue I see in the top radiator hose is that the pump is not self priming, so the coolant level has to remain at a suitable level for it to function correctly. Link to comment Share on other sites More sharing options...
rj Posted April 27, 2019 Author Share Posted April 27, 2019 From front. Image taken just under the aribox.Taken from under the car (under the pedal box)And one from under the steering rack Link to comment Share on other sites More sharing options...
CageyH Posted April 27, 2019 Share Posted April 27, 2019 Thanks. Looks tight, but isn't everything? Link to comment Share on other sites More sharing options...
rj Posted April 27, 2019 Author Share Posted April 27, 2019 Yes, tight, but doable.Not as tight as the air filter and oil inlet here https://www.lotus7.club/forum/techtalk/who-said-it-was-going-be-easyLike you say: Everything is tight in a Seven even more so in an S3 Link to comment Share on other sites More sharing options...
CageyH Posted May 3, 2019 Share Posted May 3, 2019 No matter how many times I look at this, the top hose seems the easiest location to use, and also the cheapest. Unless I am wrong, the pump will make little difference being after the mechanical pump, rather than before it. The only down side is that I will not be able to use it to bleed the system. Link to comment Share on other sites More sharing options...
CageyH Posted May 4, 2019 Share Posted May 4, 2019 How about in the lower radiator pipe, just after the PRRT? I am thinking of replacing the pipe held with a cable tie (Lower submarine pipe?) in the photo below with the EWP. Do you think it will fit? Link to comment Share on other sites More sharing options...
CageyH Posted May 10, 2019 Share Posted May 10, 2019 The pump has arrived. Lots of head scratching will occur over the weekend. Link to comment Share on other sites More sharing options...
rj Posted May 10, 2019 Author Share Posted May 10, 2019 Well,I had to alter the way the hose from the PRRT to the pump is routed as the submarine would have intereacted with the dry sump pump and the Brise tank. All in place now, just need to do up the hoses on the tank. I ended up using a 90 deg bend on the exit of the PRRT, then the S-shaped originally connected to the radiator bottom end, now via a connector to the 90 deg on the thermostat and the other end to the submarine. From this via a 90 deg bend to the inlet of the pump that I have turned to face downwards.The expansion tank will be placed on an angle bracket more or less just above the battery.The photos I took aren't very good. Link to comment Share on other sites More sharing options...
CageyH Posted May 11, 2019 Share Posted May 11, 2019 I had a spare hour this morning, so I have removed the airbox and trumpets. I have drained the system and removed the hoses from the thermostat housing, and plugged the thermostat take off with a silicone blanking cap.I have decided that the pump will form the U shaped hose, so I will hopefully just be using sections of straight 32mm hose. My new thermostat feed pipe will be placed before the pump so as not to affect the coolant flow through this hose. Link to comment Share on other sites More sharing options...
CageyH Posted May 11, 2019 Share Posted May 11, 2019 Well, the pump is in place. It certainly was not the easiest of jobs to do. The next thing I need to do is relocate my expansion tank. I am thinking of putting it on the shock support tower, using a couple of stainless rivets, through the stainless brackets shown in the mock up below.Is this a good idea? Link to comment Share on other sites More sharing options...
auyt Posted May 12, 2019 Share Posted May 12, 2019 You have done well getting it in there, however Is inlet hose below the bottom of the radiator? If not you need to bleed the pump inlet hose, a bleeder will resolve that, otherwise the pump will cavitate. Link to comment Share on other sites More sharing options...
CageyH Posted May 12, 2019 Share Posted May 12, 2019 The fill point is above the pump, so bleeding it should be easy enough. Having no standard thermostat makes it easier as well, as the PRRT makes it easier as well. Link to comment Share on other sites More sharing options...
CageyH Posted May 12, 2019 Share Posted May 12, 2019 More progress made.The car now has a new cambelt, alternator belt, dry sump belt and water pump. The expansion tank has been mounted and plumbed in. I just need to pick my G13 coolant up, fill the system and wire up the EWP. I am tempted to add a bypass switch so I can manually turn on the pump as well as letting the temp sender do it for me. Link to comment Share on other sites More sharing options...
rj Posted May 12, 2019 Author Share Posted May 12, 2019 I've filled mine with coolant today.I simply squeezed the upper hose a few times then water level in the expansion tank fell.No huge problem and I have all kinds of air traps Link to comment Share on other sites More sharing options...
CageyH Posted May 13, 2019 Share Posted May 13, 2019 Mine was filled with G13 coolant today. Pretty much the same process as Regin. I ran the system to check for leaks and to make sure that the fan started. All seems to be ok.I hate the first start up after replacing the cambelt, but everything is as it should be.Next job is to wire in the EWP, which could have been used to help bleed the system if I had thought about it earlier. Link to comment Share on other sites More sharing options...
CageyH Posted May 13, 2019 Share Posted May 13, 2019 A daft question about the wiring. I assume that as I am using the VW temperature switch that the following wires connect to the following places:Red - battery positiveGreen - Live ignitionBlack - (normally earthed) goes to the thermal switch, so it earths when the coolant gets hot, and turns on the pump? Link to comment Share on other sites More sharing options...
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