Anyone running a electric water pump, if so where did you mount it ? I don't have any cooling issues but I want to install one leaving the stock belt driven pump alone. My only reason is having the auxiliary electric pump is to run for a timed period after hot shut down/heat soak ie: like elect fans.
The problem is where to mount it in a xj-s with a 12cyl. space is VERY tight
I've tried fitting Stewart pump in the bottom rad hose without any luck .

 

What will that accomplish other than draining your battery?

 

Electric water pump is not something I would worry about the stock pump and cooling system is up to the job, even my new 6.7L will run stock radiator.

If you are determined look at this link.

XJ-SC Modifications

 

The logical place to mount it without any issues would be where the original pump sits. Why? Because that area has all the requured pipes and hoses going to it...If not, you'd cause issues with water supply (water will take the path of least restriction and if that is A oder B bank, then the other will overheat resulting in more damage than the original pump could ever cause...

 

Google "engine heat soak", that should answer a few questions. Next I believe my 140 amp alternator and year old Interstate Battery can handle the job if the pump is correctly wired, It's not like the pump & fans will run that long after shut down.
As said, overheating while running is not the subject here. Controlling heat soak is.
Recirculating the coolant AFTER shut down is the only way to do it.

 

I'm very familiar with heat soak after shutdown on both piston and gas turbine engines. It causes no real harm- especially on fuel injected engines. Running a pump and fans for a non-battery killing period of time will have minimal effect on the temperature of the engine

Not worth worrying about.

 

44Lawrence,
I honestly believe that all you need to do is just pop the bonnet on a hot day, the real damage done after a hot stop is to the rubber components under the hood. I have measured the temperatures. Bonnet closed the airtemp just above the V went from 60C at the stop to 85C in a minute or so, and stayed there virtually unchanged for an hour and was still above 70 after two.
Bonnet open, temp just above the V dropped to 50 in 5 minutes and 40 in half an hour.
Greg

 

I had an EWP on my supercharged LS3 Camaro. Beautiful set-up. It was a replacement for the stock unit from Meziere. Would cool down the engine to thermostat settings in the space of a song. It was set up for drag racing, but is generally not great for sustained road-racing.

The battery drain was not an issue, but that was on a 2011 model car. For old Jags, I'd definitely look at a battery upgrade, perhaps alternator as well.

Since you're proposing an auxiliary EWP, I see no problems except for the one you mention: the location. Wish I could help.

Padre

 

<opinion>
A good, well placed fan running after shutdown can knock under hood temps down quickly. But those temps will rise again with a huge hot block in there. Fan cycling can keep knocking them down when they rise.

An aux water pump can drop the block temp quickly and remove the source of the heat.

eFans are sufficient but both could actually be more battery efficient depending on the pump specs. Belt and bracers.

 

So why do many manufacturers choose to fit
a) electric radiator fan that will function with engine/ ignition switched off, based on temperature measured.
b) electric water pump (I believe fitted to modern Jaguar, amongst others)

 

Again, what harm is being caused to classic XJS engine bays?

 

I've been opening the hood & putting a box fan in front of the rad or on top of the hot engine forever after use, of course when possible. For the record, I'm running aluminum rad, 180 stats, elec fans, Lutz 1, Euro wrapped exhaust, two Auto Meter gauge's (one in each water rail) + the barrel gauge. Operating temp in Florida heat & traffic is around 220F @ the highest or bottom/middle of the N on the barrel gauge. With all that said, no I'm not concerned about my operating temp. Heat soak may not be an issue but it is reality in hot weather, check your laser gun. Mine reads up after hot shut down. In comparison I saw cars with elect pumps work, their temp goes down.
In any case my question was dealing with the best "location to install a auxiliary electric water pump in a v12 xj-s", not the pro's & con's of running one.

 

In the case of the V12, the loom cooks and so do the ignition components.
Greg

 

So cooling the internals of the engine with efans and an epump would not really address that vs. just opening the bonnet? Running fans and pumps would just blow more heat on the engine externals possibly making things worse.

Simple solutions are usually the best.

 

Padre:


The LT1 in my Jaguar has one of those. A work around here that has served me well.


In swapping out the Optilite, removal of the cam driven water pump was required. Near disaster, I busted the drive !!! Fix, pull the intake, tricky removal of the drive.


So, got a Meziere. All is well, and better than before. No seal to leak on to the Optilite. A major cause of their fails.


Short tem life vs long term. So far all is well.


Carl

 

Electrical water pumps can be turned on and off to tweak fuel economy... BMW use it frequently on their active dynamics system. It saves the engine having to use power (and therefore fuel) to always pump it through. Why does a cold engine need water circulated all the time? Wouldn't it help if the water flow was reduced until it was warm?

 

When you park your car in downtown (if necessary), you just don't want to leave it with open bonnet, do you?

 

I don't worry about heat soakback in the first place so I have no reason to raise the bonnet or fool with efans and epumps.

 

Yep. As if the factory cooling system wasn't enough. These cars and engines were tested to a high degree before putting them into production.

 

I live in Florida... and drive my 5.3 liter v12 Daily... it was 80F here on Christmas and I ran with my convertible top DOWN all weekend...

I had the same worries when I bought mine 2 years ago...
GUESS WHAT... keep you stock system in good shape and you are good to go! my biggest thing is warm up time... and it is shorter when everything is working right and filled correctly...

and believe it or not if you let the coolant level drop a little the elect fan does not come on as it should... when filled properly it comes on before the N in the middle...
hood vents... not necessary... there are stealth hood vents that no one notices.. While your electric fan is running and the engine ... walk up to the front wheel and place your hand over the gap between the engine cover and the fender... you will be surprised the amount of Hot air that is being forced out... Stealth hood vent...


really I would like it not to cool off so fast... I would like the oil to stay to temp
I go to lunch... then I get off work 4 hours later and take the long way home to have more fun get the temps up and be able to get the Revs up ( when the oil Pressure comes down) and the gas mileage to a nice 10 mpg


ENJOY the car!