Craig Davis EWP150 Electric Water Pump & Controller & COOLING

[Hybrid_From_Hell]

Cooling .....

The 5.2 still causes problems cooling, after some more research found that this engine actually did have one, whicgh must have been sold off / lost on route through the owners / bodgers till I got it,

To try to sort it has

Thermostatic Restrictor plates instead of Thermostat (Helps / aids flow vs a thermostat)

Alisport Ali Radiator Plus twin Spal High power fans - 10-15 degrees off but still not enough

Trioed water wetter - made zero difference

Changed fans to come on earlier - better

Vents in side

and a few other things - all in all too hot

So, Now its the chance of the EWP150 pump and controller to sort this engine outr, I am assurred by many it will make a vast difference ...so heres the tweek thread of what it is, how it fits, and eventually is it any damned good ??

What is it and how does it work ?

Basically a controller has a "Target temperature" come what may ...mine will be 80 degrees, the controller has a sensor and the sensor speeds up or slows the flow of water through the rads (and can control fans too) so that the target temp is maintained. You have a pump which not only is vastly more powerfull in terms of flow, but the speed of the pump and thus the flow is NOT connected with engine rpm, which standard water pumps are .

Kit arrived, aliuminium Pump body - will shift up to 150 litres a Minute !, wiring loom plugs in fact a solid bit of kit with sensor, and controller

Sensor has a nasty plastic hose joiner, we decided to modify a V8 Housing and drill tap and add the sensor to it there, the instructions do say this is best but more work, but easy done, due to the tightness we linished off a differing angle, still gave 12mm thick casing to tap into, which is 11mm drill and 1/8 BSPT.

The water pump was finally off (again) and the impelloe carefull removed - this ewp150 unit must have the waterpump impellor eemoved, the smaller units they do are more "assisters" but the 150 needs to have total control to work and flow max. rad and fans and bits out bottom hose of existing gives an idea of loacation :

Also modified the breather hole - I am sure pressure washing and off road dirt gets in the air hole on water pumps and cause failures so we have vented it with brass barb fitting and some pipe :

Where to mount the pump ??...it can go away up sidewats etc, and high or low, but goes into the bottom hose to Radiatotr base ...we offreered around all sorts of hoses, it was very very tight anyway in that area, what we have now is ecven better !

We ended up using some of the origianl hoses and joiners cuts around and rejuiggled, and a THJOR 4.0 Rad Hose and bingo all fits in neatly :

Still tight as anything down there but better !. The sensor wire connected and joins the rest of the loom which is going to go along the underneath of the challenge wings and into the cab to connect to the controller

Bit of wiring to do, and mountings to be made to hold pump in place :

More later

[Dave W]

When is it giving you problems ? High speed, low speed ?

Been thinking of fitting something similar to mine, currently cools fine at higher speeds but has a tendency to get progressively hotter at low speed. Opening the bonnet cools mine down so I'm looking at airflow but an electric water pump for better coolant flow is something I've been considering.

[Hybrid_From_Hell]

Problems are when power is on and heat is gernerated, or traffic, but heavy foot low off road speeds and high torque = HEAT

and getting back on top and temps down is the constant problem

On the road crusising no probs.....

[landkeeper]

has your rad any sort of cowl ?

[Team Idris]

Normally I'd advise this kit as a; "come on, what's really wrong with it" but I think it will do well on an engine that suffers low circulation at low speed and cavitation at high speed + high fuel use in a small package.

My favourite install saw the bottom hose connect to the hole where the water pump bearing-cartridge used to be. But it was a rear rad, so a 90 rubber elbow pointing to the LH side was very neat.

I do wonder how it would be if the standard pump had an electric motor? But I imagine the real-deal has a very efficient impeller?

Looking forward to hearing the "it works well and fixed the overheating"

[Hybrid_From_Hell]

Yup full tight cowling plus 2 x pulling SPAL HD Fans

[zim]

Mr Nige,

I know i'm being pedantic, but :

Davies Craig :

vs Craig David :

[Les Brock]

Think it'll take 7-Days to get it workng ?

[Cheesy]

No spare output for the megasquirt to drive it?

[zardos]

May be your problem is not getting the heat out of the engine but keeping it out, the first thing that the removed heat does, is to to re-heat the engine (a problem of having the radiator in front of the engine :-) )

I had a 3.9 v8 with radiator up front which was barely handling the conditions (extreme low gears, thus very little forward movement and air flow), I then moved to a rear radiator setup and it now hardly troubles one of the 2 fans.

I know that you might not be easily able to accommodate a full size rear radiator, but have you thought of adding an additional smaller one (one trick I used with the old setup was to turn the heater on full hot because this acts like a small radiator :-) )
Rear radiators also have the benefit of adding extra coolant and pipework (extra surface area)

[elbekko]

Or a fan to pull hot air out of the engine bay? You mention you already have vents in the sides, put some large computer case fans on them, they're 12V already.

[Team Idris]

Could keeping the heat in by moving it too the rad be the problem? I guess so, but I've had my rads running in 60 degree centigrade ambient and blowing onto the 500hp cat engine at 90+. All was happy, but it is true that if your rad increases it's exit heat, the engine surface cools less. If the rad is in the back, the engine is then running in cool air and it is probably over a meter square of surface area. Unless like me you block the front up

What I do see regularly, is problems where there isn't enough flow to carry heat away. (this can be water side or air side). If you increase the engine power but have the same pump flow, the only way to shift the heat is to have a rad that pushes out a lower temperature from the bottom hose. (Or push up the water temp). Or, you can send the water round and around faster.

It's easier to make the big CAT do desert work because it does 500-600 litre/min jacket water flow. The newest Cummins do nearer 200 lit/min. The rad has to be bigger on the Cummins to work in the same ambient temperature. So I think the available RV8 pumps don't have the flow to make a high power engine cool right?

[zardos]

Interesting diagram

Increasing flow rate does increase the heat flow rate, but it is diminishing returns and at some point it will get worse due to aeration.

Given that you have tubular wings, would it not be easy to put additional radiators mounted in the wing tops with fan blow air from underneath.
Or from the pictures it looks like you have an oil cooler behind the rad, may be move that the be mounted in the wing with fan blow air from underneath?

[zardos]

Another interesting read http://www.arrowheadradiator.com/14_rules_for_improving_engine_cooling_system_capability_in_high-performance_automobiles.htm

I so reading this I would also remove the restrictor plate you have instead of the thermostat (in my rear rad setup I have no thermostat because I've also removed the flow path when the thermostat would be closed)

[Team Idris]

Above seems spot on. Make the system have as little resistance as possible and connect the pump outlet to the highest resistance part (could be engine-block or rad?). Although I suspect they want the pump fitted to the cooler side of the rad, so it stays cooler. But it makes sense to avoid sucking through the most restrictive part of the system.

[Dave W]

Never really thought about the effect of faster coolant flow in those terms. So it doesn't improve heat dissipation as such but averages out the heat across the engine better, reducing peak high temperatures and increasing low temperatures.

I'm still convinced my problems are down to air flow rather than coolant flow but if increasing coolant flow helps reduce the peak temperatures then that will also, presumably, mean that the temperature increases during high load use will be less extreme. I've measured mine looking at radiator performance using an IR thermometer and the difference between the top and bottom hose aluminium casting is as much as 20C with the bonnet open.

I've added a vent to the back of the bulge on my bonnet that has helped a small amount - going to fit 3 computer fans under the vent as heat extractors next.

[Hybrid_From_Hell]

You must run a plate as a minimum, or you will get cavitation I am relaibliy informed !

N

[HoSS]

You say you have an alisport (Alu?) radiator? I was reliably informed by a specialist rad builder that copper core rads outperform aluminium ones significantly.

[Team Idris]

Copper or ally makes no difference. You don't hit trouble until you use stainless, and even then the heat transfer process is still driven by the geometry of the fins on the inside and on the outside of the tube (if there are any inside). The main reason ally is considered better is because they are fully brazed together, whereas only the first 5mm of some copper rads were soldered. Heat had to travel between tube and fin by touching only. A lot of mini rads are like this. Also, the ally rads tended to have better louvered fin. Both metals are good conductors of heat and electricity.

Air blast heat exchangers are mostly controlled by the air-side. It's about how hot air on the surface of the fin is stripped off and replaced by cool air by the louvers. Or by turbulent air with flat plain fin. Or just by having a huge amount of surface area because the flat fins are 1mm apart (my van rad).

[Team Idris]

What makes it all difficult is that a really big thin rad is the ideal. Reality doesn't let you do that, so I was drawing one up last week that's 138mm deep with a 94mm oil cooler behind it. It's always some compromise about space and the amount of power of the fan that's available and pump power. Another customer only has 10amp at 24 volt. He's maybe in the worst spot, as he will have to change his machine to need less cooling. There's a lot of science in it, but with so many variables it soon slips into an artform

[zim]

You must run a plate as a minimum, or you will get cavitation I am relaibliy informed !

N

I don't run a thermostat or plate. Not had any issues and it cools perfectly with a rear mounted rad.

G

[Boothy]

I run nothing, no restrictor, no baffle, no thermostat, no controller and no problems.

On my old 3.9 I removed the spindle and the bearing etc of the pump, alloy welded a small plate on the side outlet neck and the built and ground the old spindle housing up and ended up with a perfectly round front hose outlet, which I just fitted a 90' elbow to and "hey ho" it was the perfect way (and increadibly neat) method of connecting to the pump.

It all worked faultlessly with my alloy rear rad set up.

Stop flaffing around and get on with it man.....

[zardos]

You must run a plate as a minimum, or you will get cavitation I am relaibliy informed !

N

All the extra pipe work of a rear radiator probably has the same effect as a restrictor (extra resistance)

More likely needed to balance out the pressure so that some water goes via the heater circuit if you have one (I don't)

[B reg 90]

One thing I think that gets missed is the volume ratio between the air space in the header tank and the water volume in the cooling system.

Too much volume in header tank - expansion of water in system does not compress the air sufficiently, hence lower pressures in the system as temps rise. Low system pressure means lower water pump suction pressure. This equals a higher likely hood of cavitation. Once cavitation starts the water flow rate drops, water flowing out of the block gets hotter, suction vapor pressure at pump drops, more cavitation, less heat removal etc.

Too little volume in header tank - expansion of water in header tank raises pressure of air to greater then cap set pressure. Air/steam vents. System stays at roughly cap pressure until engine stops and cools. Because some air/steam has been vented and cap does not let it back in, the cooling system when cooled back is then lower than atmospheric pressure (vaccum) as it has a lower mass in the same volume. When engine is next run the expansion of the water only raises the system pressure by roughly the same amount, but it has started from a vacuum, end pressure can be low enough that the pump suction pressure is to low and the pump cavitates, low flow, water leaving block is hotter, pump cavitates, etc. This is one of the reasons there is a label on radiator caps that state ' only remove when cold'.

l plan on fitting a pressure gauge to my cooling system when I eventually get my M57 engine running so I can see what is happening.

[B reg 90]

You must run a plate as a minimum, or you will get cavitation I am relaibliy informed !

N

Yes you do, but there is another issue with removing the thermostat. You lower the resistance to flow of water in the system. The pump flows more water. The water is in the block for a shorter time, hence warms up less. However as the temperature difference between the metal and water is greater (higher thermal gradient) the heat flow out of the block is higher when compared to a lower flow of water. That sounds fantastic, your removing more heat (BTU's, Joules, Watts or what ever your unit of choice is). However you now have a high flow of 'colder' water going to the radiator. The temperature difference between the water and the passing air is lower. Hence the heat transfer rate out of the radiator to the air is lower. If your radiator is the same size as it was before you removed the thermostat, then the heat transfer capacity of the radiator has dropped. Water temperatures going back to the block are higher, water temps coming out of the block increase, higher water temps back to the block cause lower vapour pressures at the pump suction, cavitation can occur, flow drops, less heat removal, etc. Coupled with the fact that with high flow rates the water pump needs a considerably higher inlet pressure to prevent cavitation (set by radiator cap pressure and header tank sir space to water volume ratio), every thing is fighting against you.

In short if you remove the thermostat you may need a bigger surface area on the radiator to dump the heat if the radiator is the limiting factor. Even then due to the lower cooling system resistance, the pump will flow more. It will hence need a higher suction pressure to prevent cavitation. If cavitation occurs the engine will over heat and the situation will get out of control.