After upgrading my XJR inter cooler electric pump to a Bosch 010 I noticed that the path of the water flow is opposite of what it should be.

From the factory, the water is pumped from the pump into the radiator, then up to the charge coolers, then back to the pump. It seems to me, that in this arrangement it is much more likely to get an air bubble stuck in the impeller and fry the pump.

If one were to reverse the flow as seen in the photos below, then the pump, in theory, should be already gravity fed pre primed with fluid and much less likely to get an air bubble stuck in it.

At any rate, the swapping of the inlet for the outlet was pretty simple. All I did was cut the inlet and outlet hoses and switch where they went. A now goes to B, and B now goes to A. A simple 5/8 brass fitting was used as a joiner and then a couple of hose clamps per hose. Super simple really. The photos show the progression of steps.

The photo of me holding the pump shows the hoses after they have been cut and ready to re-install in the stock location.

So now (after reversing the direction of flow) the pump gets fed from the passenger side outlet on the radiator and pushes fluid up into the charge coolers. It is my opinion this will significantly reduce the chances of getting an air bubble in the pump which could cause it to burn out and thereby cause other problems by then not moving cooled fluid to the charge coolers.

 

Have you noticed any change in cooling?

 

I have not yet started the car as I am still waiting for my blower to return from being rebuilt. The High Speed Lab is slow....but possibly very good quality.

I do not expect the car to run any cooler because of the reversing of flow as the water still will go to both charge coolers. The purpose of reversing the flow was to significantly reduce the possibility of the pump ever getting an air bubble in it.

I did notice my last xjr (the blue one) ran cooler with the 10" pusher fan when running the 1/4 mile, but I had also deleted the lean tune, which would have added some significant amount of heat.

I expect this xjr to run much cooler under WOT because I have significantly increased it's ability to remove heat in real time by adding:

12" pusher fan in front of the inter cooler radiator so I can still bring the IATS down when at a stop or driving slow
upgraded to Bosch 010 inter cooler pump with something like +15% more flow?
Water/meth injection running a conservative 375 ml/minute to start
Inter Cooler spray fine water mist on to inter cooler radiator
I'll be running mostly water and less coolant (90/10) as water is a better heat conductor than coolant. It never freezes in my garage in California.

I expect the above 5 mods to remove a significant amount of heat as it is being made. I will be running a lower pulley on a ported 5th gen Eaton M112.

By running the water/meth before the blower, that alone should add 1-2 lbs of boost by giving the rotors something to move and helping it seal a little better.

The 12" pusher fan moves a decent amount of air.

Fine water mist sprays on the inter cooler radiator have been shown to cool the IATs in the -20 degrees F+ range. This could be quietly done before running the car hard for the best benefit and/or during a WOT run to significantly help keep the IATs down continuously. The high pressure fine mist spray does not drip water as it all evaporates. If you had even one drip at the starting line at the 1/4 mile track, they will throw you off the track for creating unsafe conditions.

 

I have seen a schematic of the system showing the direction of flow, and it shows the flow going from the rad (actually the intercooler heat exchanger, not the engine radiator) to the pump.
Here's the one I found on the forum somewhere; DISCLAIMER: I don't know the source of the drawing or which models it is for.
[IMG][/IMG]

 

The "In" Water comes up through the bottom of the pump, and the "Out" is sideways out of the impeller. There is even a small arrow to indicate direction of flow.

On my car the in was from the charge coolers and the out was to the radiator.

I have since switched these two.

The above pic shows how "it should be" and how mine is now plumbed, after reversing the flow, not how mine was. Both of my XJRs were plumbed "backwards." Maybe this is a schematic of the flow after someone figured out their design mistake and corrected it? OR maybe they have been plumbed backwards by mistake at the factory, I don't know.

My main business, since the age of 16 has been aquariums, I personally have over 8000 gallons of personal aquariums at my house, so it was immediately obvious to me which way the water was flowing and that it was the reverse of your schematic above.

 

I just went and looked at mine, seen here:
[IMG][/IMG]
I then tested it, and yes the water goes from the intercoolers, to the bottom of the pump, and out to the heat exchanger. Has air in these systems been a problem? This is my first XJR and I am curious.
The other thing I notice is that diagram does not have the connection between the intercooler water and the radiator water.

 

It has been a problem a few times, people reporting burnt out pumps from air bubbles, so, given it is so easy to "fix", I suggest doing it.

And yes, no direct link between radiator coolant, which is a good thing. They only share the expansion tank or whatever that "thingy" is called.
This allows the inter cooler circuit to run independently, on a temperature basis, from the engine coolant, so you could benefit from adding a inter cooler water mist to get the IATs down another 20 degrees F if you wanted to quite cheaply.

Pretty cool, eh? <---See I can speak Canadian too My wife grew up in Toronto

 

Mine does have a connection, where the lines are on the LH side of the engine. It's a small pipe, but I figure it's there to allow for expansion, since the intercoolers don't have a tank of their own.
[IMG][/IMG]

 

Exackalies

 

I don't see the sense in it because the head of water is higher on the intercooler side of the pump. And in the stock setup, that is the inlet side. So, the higher head is priming the pump.

It is further complicated by the siamese connection on the radiator lower hose. You want the engine to be able to suck up as much water as it needs, but by reversing the intercooler pump, you put suction at the joint.

I'd rather starve the pump than the engine.

Maybe the burnt out pumps suffered cavitation when the coolant was low on both sides.