12V electric Water pumps - how are they fitted

[PeeBee]

Guys, How are the electric water pumps integrated into a typical engine cooling system? Are they plumbed in-line as a flow booster or are they a replacement? If a replacement, how do you run a mech fan and close up the hole in the block?

Are they useful in controlling engine temps if things are getting hot? Do they put further stress on the radiator?

I have seen them advertised and having a potential @mudski kettle on my hands with the power upgrade am trying to take a proactive approach. Anyone using one on a Patrol now?

[the evil twin]

Dunno how (in a hybrid elec and mech) an eleccy water pump would do diddly squat for your temps unless your mech pump was waay under spec.

If your chasing big power then you may exceed the factory mech pump flow capability to get enough deltaT across the Rad I spose (cooking from the inside out)

Increased flow can be a double edge sword tho... too much flow and the coolant doesn't stay in the Rad long enough to dump the heat (cooking from the outside in).

I would be more looking at increased oil cooling and more efficient radiator.

Unless the cooling circuit capacity is changed (hi flow thermos etc)I can't see how you will increase flow without an increase in pressure.

[PeeBee]

I lifted this passage from a website in the US who manufacture high performance water pump impellers. I have sent them a question regards a modified impeller for my new pump, that is yet to arrive.

In a closed loop system if you keep the fluid in the heat exchanger you are simultaneously keeping it in the block longer. Unfortunately, the block is the part that is generating the heat. Sending hot coolant from your source (engine) through the heat exchanger (radiator) to the sink (air) will transfer heat as long as there is a temperature difference between the source and sink. The engine is still generating heat the whole time so why keep the coolant there any longer than you have to.

Here is the link to their site, makes interesting reading, and presently I will be upgrading from 65gphr to 130gphr, however if i can shift more than that I will go this mod. for sure. One of the guys on a chev optimiser forum is waiting for his impeller to arrive also, so will see what that delivers. These guys make a range of impellers and no doubt one would fit a patrol, although there is a company in aussie I believe already doing it. I guess it speaks to the issue of higher flowrate and greater cooling, which was initially what I was thinking about with an electric booster pump.

https://www.flowkoolerwaterpumps.com...nd-overheating

[the evil twin]

Yeah, I get what they are saying... but... the deltaT of the engine to coolant and the rad to coolant aren't linear in isolation nor interdependant.

While you are on the side of the curves where the deltaT of the Rad is better than the engine any increase in coolant flow will reduce temp. Thats the job of the thermostat, see an increase in temp and it increases flow and is also obviously why cooling systems with blocked cores etc overheat (a combo of low flow and reduced transfer efficiency due to scale etc)

Get on the other side where the engine puts in more than the rad takes out and the opposite happens.
Higher flow will pull more heat away from the engine but it also means you now have to get more heat out of the coolant because it is a closed loop. Open loop it is a no brainer but closed loop can be an issue

So IMHO flow will be a benefit but it comes back to where is the best efficiency gain, oil cooling, increased rad capacity, increased coolant flow, increased air exchange, coolant mix etc

If flow was the one stop answer to cooling issues every TD42 in Oz would have a gazillion LPM pool pump under the bonnet.
I don't disagree that it will help, of course it will which is why hi-flow thermostats etc exist.
Just thinking additional pumps aren't the first place I would go unless I knew the existing pump capability was maxed out so a higher capacity impeller would be a consideration.

[mudnut]

As our learned friend ET has stated, too much coolant flowing through the radiator, will reduce the time it has to transfer heat. That is why, as a quick fix, you have to resort to drilling a hole or holes in a seized thermostat, instead of just taking it out. This is to restrict the flow rate.

[PeeBee]

Agree with your logic. I will see what they come back regards a more efficient impeller first

[PeeBee]

As our learned friend ET has stated, too much coolant flowing through the radiator, will reduce the time it has to transfer heat. That is why, as a quick fix, you have to resort to drilling a hole or holes in a seized thermostat, instead of just taking it out. This is to restrict the flow rate.

Muddy, have a read of the info from the link I posted, they pose some counter arguments to that hypothesis that seem reasonable and slap that fix out of the park.

[mudnut]

Well, I am a grandpa and have seen the restriction work, so whichever way it did it, I still got home without cooking the engine. Glad to learn it was the increase in pressure, not the reduction of flow through the radiator.

[BillsGU]

I went through this exercise some years ago (not with a Patrol though). I inserted a Davis Craig in line electric pump. This pump arrangement worked well because with the electric pump OFF, the original mechanical pump worked "through" the electric pump. With the pump ON (when the engine was working hard) it obviously greatly increased the water flow, but it only reduced the water temp by a small amount because there was not a lot of time for the heat transfer to take place in the radiator. To solve this I purchased a more efficient radiator and turned it into a Triple Pass radiator. The coolant stayed in the radiator much longer and all my overheating problems went away.

[PeeBee]

Well, I am a grandpa and have seen the restriction work, so whichever way it did it, I still got home without cooking the engine. Glad to learn it was the increase in pressure, not the reduction of flow through the radiator.

Its interesting this stuff I reckon.