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That is an OK stop-gap solution but requires modification to the thermostat to remove the bypass section and manually block up the bypass channel. Otherwise coolant flow will pass straight across the front of the engine and not through it. While going to that effort, it is better to incorporate a proper bypass thermostat, as this (when used in combination with the controller) gives you faster-than-factory warmup times and rock-solid temperatures.
I'm not too fussed about the fan control because pretty much every aftermarket ECU offers that. Otherwise, you can get programmable thermatic switches which will do the job. Davies Craig actually makes a cheap standalone one. I used this for years without issue. It switches off the fan 5'C below the set-point, which you can set wherever you want it.
I have a spare pump housing at home, I'll take a look when I get home tonight. I can't quite visualize the coolant flow without looking at that. I'm not sure what negative impact there would be based on a small amount of coolant to bypass the front of the engine as you mention above. That would only be until the thermostat opens and wouldn't that help warm the motor up quicker? Once the thermostat is open it shouldn't be any different than I am right now without a thermostat correct?
Anyway I'll check the pump housing tonight and see where all the paths flow.
So after checking the coolant passages I can see an EWP would push coolant back up the stock by-pass passage and effectively have coolant by-passing the engine.
As suggested by Davies Craig I took a stock 82C thermostat and drilled 3 small holes, (4mm), I also screwed a blanking plug into the by-pass passage behind the thermostat. May be not a permanent solution but does tighten and good for testing without welding the passage closed.
First test showed that air locks are forming at the throttle body again now the thermostat is back in, without the thermostat the car self bled the air but with the thermostat I had to bleed air from the throttle body.
Got the car out today (bonus was Pistonheads meeting at Alcon so got to see how they machine calipers etc), weather was much cooler than previous test, probably at least 10C cooler ambient temperature.
Had the ambient been higher I may have noticed an improvement but as it was I still couldn't get up to temperature, low 70's was the normal, I could increase this a little by raising the pump controller set point to 90C.
I have a temperature gauge in the pipe from the rear iron to the throttle body, this has always been fairly consistent with the ECU temp with the mechanical pump and was also consistent with EWP without the thermostat however now with the thermostat back in the car would heat up at idle and temps would be consistent but as soon as the car started moving the throttle body temperature dropped, wax pellet hardened and temperature dropped all the way down below 40C. Obviously left me with a high idle even though the ECU was in the low 70's.
Once the car is stood still for a few minutes the throttle body temperature recovers.
I'm really not sure why this would be happening just because a thermostat is back in place, may be something else is happening but I'm not seeing what it could be.
Any suggestions welcome.
I'd like to have more control over the pump duty cycle but that means a separate controller as Davies Craig only have the fixed solution, I also think the 150 might be too much pump for a 13B, may be the 115 would be a better match for the flow required to cool a 13B, at least for a predominantly street driven car.
I can't think of an explanation for the throttle body behaviour, although it may have something to do with the thermostat being used without a bypass and this has altered the coolant flow path.
My suggested solution to the overcooling is to use a normal unmodified OEM thermostat and tap a fitting into the bypass channel, then run a hose from there to the heater return. For this to work, the bypass needs to be blocked from the bottom (mechanical water pump side). See picture below (which is something I made up in MS Paint 10 years ago or so).
.
This will restore the factory coolant flow path and allow coolant to recirculate throughout the block when running temps are below 82'C. If you set the EWP target temp to 85'C, then means the pump will most probably keep temps around 82-85'C, with the electric fans only coming on 90'C, which will probably be rare due to the capacity of the EWP150. This is the way I have been running it on an EWP80 since around 2005 and it is perfect. On my new turbo engine, I will be using the same setup with an EWP150.
It bleeds up fine cold, but takes a little longer for the air to burp up with the thermostat blocking it. It helps to prevent air getting in the system in the first place by ensuring you fill the coolant slowly with the heater tap fully open.
Rather than modding the water pump housing, you could also run one of the remote bypass thermostat described earlier in this thread, which is a neater and simpler approach.
I can't think of an explanation for the throttle body behaviour, although it may have something to do with the thermostat being used without a bypass and this has altered the coolant flow path.
My suggested solution to the overcooling is to use a normal unmodified OEM thermostat and tap a fitting into the bypass channel, then run a hose from there to the heater return. For this to work, the bypass needs to be blocked from the bottom (mechanical water pump side). See picture below (which is something I made up in MS Paint 10 years ago or so).
.
This will restore the factory coolant flow path and allow coolant to recirculate throughout the block when running temps are below 82'C. If you set the EWP target temp to 85'C, then means the pump will most probably keep temps around 82-85'C, with the electric fans only coming on 90'C, which will probably be rare due to the capacity of the EWP150. This is the way I have been running it on an EWP80 since around 2005 and it is perfect. On my new turbo engine, I will be using the same setup with an EWP150.
It bleeds up fine cold, but takes a little longer for the air to burp up with the thermostat blocking it. It helps to prevent air getting in the system in the first place by ensuring you fill the coolant slowly with the heater tap fully open.
Rather than modding the water pump housing, you could also run one of the remote bypass thermostat described earlier in this thread, which is a neater and simpler approach.
Thanks.
I'm actually in the US at the moment so will look at this again when I'm back in the UK.
I assume filling the bypass passage with some form of epoxy would be okay?
Yes if its ok for use in rotor housings, it should be equally fine here. Personally i got it welded shut for no other reason than it was more convenient at the time.
Yes if its ok for use in rotor housings, it should be equally fine here. Personally i got it welded shut for no other reason than it was more convenient at the time.
I'm struggling to identify what is the correct type of epoxy to use, I thought something like below sounds right but it appears to only have a temperature rating of 121C:
I'm struggling to identify what is the correct type of epoxy to use, I thought something like below sounds right but it appears to only have a temperature rating of 121C:
Not sure whether this specific product will adhere to alloy but it is also rated to 120'C - so I'm not sure it's cause for alarm. There is an alloy version of it with the same rating. I'm sure there will be info on the board here about it as I'm sure people have used this or something to fill intake manifold ports etc.
Not sure whether this specific product will adhere to alloy but it is also rated to 120'C - so I'm not sure it's cause for alarm. There is an alloy version of it with the same rating. I'm sure there will be info on the board here about it as I'm sure people have used this or something to fill intake manifold ports etc.
Thanks, I have some metal putty that adheres to aluminium, I thought a pourable liquid might be better to ensure the full void is filled but maybe I can pack it with putty.
By way of update, I just found a whole bunch of photos from when I originally figured out the necessary water pump housing modifications. I posted these online back in the day but they were lost when Imageshack went bust. I have posted these back up online now! See here: Electric water pump ??? - AusRotary
Just thought I'd post a word of caution for anyone looking to go the Landrover thermostat route. I have purchased two units from different sources, one part# PEL500110 and one part# PEL500110G, from online research it would appear both should be 82 degree and the "G" version would have a softer spring.
I tested both in a bucket of hot water along with a standard RX7 thermostat, stock 82 degree thermostat was wide open but neither Landrover thermostats opened, my gut tells me these might be 95 degree thermostats.
It also appears that the bypass does not operate like the RX7, the bypass plate is closed and seems to require water pressure to actually push it open. As the thermostat open the spring pressure on the bypass plate would increase and so I assume hold it closed.
I have not progressed to installation yet until I am confident I have an 82 degree unit but I'm not sure this solution will work as desired because the EWP isn't going to apply much pressure to open the bypass when at 6V and only pulsing for 10 seconds during warm up.
Just thought I'd post a word of caution for anyone looking to go the Landrover thermostat route. I have purchased two units from different sources, one part# PEL500110 and one part# PEL500110G, from online research it would appear both should be 82 degree and the "G" version would have a softer spring.
I tested both in a bucket of hot water along with a standard RX7 thermostat, stock 82 degree thermostat was wide open but neither Landrover thermostats opened, my gut tells me these might be 95 degree thermostats.
It also appears that the bypass does not operate like the RX7, the bypass plate is closed and seems to require water pressure to actually push it open. As the thermostat open the spring pressure on the bypass plate would increase and so I assume hold it closed.
I have not progressed to installation yet until I am confident I have an 82 degree unit but I'm not sure this solution will work as desired because the EWP isn't going to apply much pressure to open the bypass when at 6V and only pulsing for 10 seconds during warm up.
A little more research is required.
Thanks for sharing. Thats very unfortunate and a pain when manufacturers don't publish accurate specs.
The observation about the bypass is very weird. I'm not sure that would necessarily work in factory guise either, as a belt drive water pump at idle is not going to be producing much pressure either. The flow rate is proportionally to the crankshaft speed, so I wouldn't be surprised if the EWP at 6V actually produces more flow than the factory pump.
Another update on the remote Landrover thermostat.
I have just returned from Rimmer Bros (www.rimmerbros.com) I found they stocked the thermostats and were only 5 miles from my house. Anyway they had the original Landrover brand grey thermostat with soft spring and the OE (creamy/white) replacement (same as previous unit I purchased from another supplier). I explained to them that during testing in hot water the one thermostat didn't open, they knew about this and explained they had also done some tests to find after speaking with Landrover that some of these thermostats also require pressure before they open. I have no idea what is different in these stats that require pressure but it explains the test result I had.
Anyway once I had the grey Landrover thermostat and could compare it was clear this is the only unit to use from this design of housings. The creamy/white unit is listed as an OE replacement with same specification but the bypass spring in the grey Landrover unit was much softer. I now think this could actually be a solution and will proceed using the grey housing, of course being a Landrover part it's double the price but I think it may work whereas I had no confidence in the others.
Might be a couple of weeks before it's together and tested as I'll actually be in Chicago next week on business.
Hi Richard how have you got on with this now? I’m in the U.K. and have the same issue with over cooling. I have just made an adjustable plate across the rad to limit sir flow to try and stabilise the water temps
I did some road testing probably back in November now when it was colder weather and the system worked well, it now maintains a normal running temperature and I still have the benefit of the electric pump for continued running when the engine is shut off.
Hi Richard
that sounds like you have finally cracked the issue then. Would you mind if I PM’d you a few pics of my set up and offer some advice please?
thanks Mark
Richard, that's amazing! Thank you so much for the video and the description you provided.
What was the part number on that T-stat housing by Landrover?
I'm going to give this a try.
Cheers!
Sorry Bruce, I've just seen your post. I'm in the USA at the moment, I'll see if I can dig out the part number this week if not I will definitely get it when I return to the UK.
This part is grey in color and comes boxed as a Landrover item, I do not recommend anyone purchases an OEM equivalent as the springs felt much stiffer on ones I tested side by side.
I'll see if I still have the Landrover box when I get home, if I do I will post a picture, that will be in a weeks time however.
07-20-18, 02:22 AM
