Hypothetical generic question... If you have an engine (any engine) and have removed the standard mechanical waterpump in favour of an Electric Waterpump. Would it be feasible to be able to remove the mechanical thermostat and have the water circulation controlled by a thermister that regulates the Electronic Water Pump ? ie pump is idle until a set temperarature is reached then water begins to circulate as temps rise to normal ? I ask this because i would extremly simplfy my plumbing on the 1JZ and do away with the bulky thermostat housing.
I would leave it in , without it water will flow too fast to pick up heat properly. Dosen't matter whether its a electric or a mechanical pump moving the water . Trev
id take it out definately alot of race spec V8s with EWPS run without thermostats. you should set the ewp to have speed cycles. depending on engine speed and temp. it should always be on
Mechanical pump is purely reliant on engine speed, the Electronic pump can vary speed depending on the situation. so if it needs to go slower for the heat transfer process it can.
The thermostat is used to control the flow of coolant. If you are using an electronic water pump on a thermal switch then I would remove the thermostat as it is no longer required.
Yes stu it is possible to remove the thermostat completely when using a electric water pump, with the electronic controller modulating the pump, the pump will not run untill 75 degrees say, which can give decent warm up times The disadvantage of this setup is that while the motor is warming up there is no coolant flow at all , so this can lead to hot spots and localised boiling i guess in coolant galleries around exhaust valves etc as that coolant will not move untill your sensor in the top hose see's 75 degrees. They say the best way is to retain teh thermostat, and drill a small hole in it for extra flow
Why don't you gut the thermostat and leave it in there, let the thermistor do its job. is there any way to monitor the temps around the back of the motor? You will find alot of race cars using this setup (electric pump)will have restrictor plates in the cooling system , its trial and error with these hense the need to monitor a few temp points around the motor. Trev
I'm chucking my thermostat. The davies craig water pump controler jog runs the water pump to keep some circulation when the temperature is below operating and adjusts to suit. If the water pump is just running all the time leave it in, if you have one of those fancy controllers bin it IMO.
I have fitted the ewp and removed the pump impellor and thermostat. The pump will cycle just enough to stop hot spots occuring but the engine seems to take a little longer to warm up. This suits me as i dont use my zed to shoot up to the shops and back. The controler, once warmed up holds the temp rock stable. Best money i have spent for my zed!
The last time I looked into this (I ran the EWP GB ages ago and was going to run the controller GB) I was of the opinion that the controller doesn't jog the water flow till it reaches a certain temp. This was my issue with it and I raised this issue with DC and they couldn't comprehend the issue. Where are you mounting the EWP? at the stock water pump location via a block off plate? if not, then you'll compromise the flow paths and I wouldn't do it (I didn't do it - I built a WP block off plate... actually I still got it, will sell it when I can be bothered...)
Sounds as though he doesn't have a very good understanding of how cooling systems work in cars. With the thermostat closed the water in the engine is still circulated by the pump - the heater wouldn't work until the engine was up to near full temp otherwise. (in a standard set up mech pump & thermostat etc) Odd you would think he would know that.
You guys know that hot water rises and that mechanical water pumps were not features of old cars. the heat/ convection process works surprisingly well and as mechanical thermistats restrict water flow to almost nothing when cold will show that the convection system works before the thermistat opens! Anyway im hapy with my setup and it will pump to the engines requirements regerdless of engine speed and can even continue after shut down to avoid boiling in the engine (think race aplications or B/S hot traffic)
another thought If you do a search you will see that this has been discussed at length a few times. Now I am not doing a rant about using search, but it is a leading topic for those who want to research it further before I add my 2cents. It is just not an easy removal of the thermostat. The back of the thermostat needs to be block off to prevent the flow from just circulating around through the cold and hot pipework once the EWP is installed. The way I did it on the E-Vades is I take the housing off and weld it as shown below (normally a better well than this). But I am sure that you could attach a plate via other methods. I know there is a lot of arguments for and against this mod. Such as what happens if the pump stops, you blow a fuse, etc. But they can apply for the mechanical one too; ie. what happens if the pump seizes, the fan belt breaks, etc. It is just a question of what you surmise yourself as the best options. As for the 1JZ I am not overly familiar with that engine model so just make sure that you prevent the water flowing the wrong way through the old hot water recirc section of the thermostat, otherwise it will limit the maximum cooling ability and may cook the motor as the water won?t be circulating. This is not entirely possible for the zed as it has a separate outlet for the heads, but could result in about 1/3 just being recycled. I hope this makes sense.
I reused the pump but minus the impellor. If i was to do it again i would delete the pump altogether. With an underdriven crank pulley you can run a belt straight to the alternator without including the pump. When i measured up my possibilities i still had the factory crank pulley in place and thought the timing teeth on the timing belt cover would foul. This wont happen on the under drive pulley.
The EWP needs to be installed at the same location as the factory water pump in order to retain the factory coolant flow directions. I've been over this plenty in the past and there has been some heated arguments over it (zorro got upset with me cos his was implemented in the lower radiator hose and I was saying that's a compromise) I posted up pics of the service diagrams in the past showing why it's a problem, can't seem to find them now tho
