Thoughts on proposed Electric water pump installation.
Turbo Mini Forums

ok - I can't find my flashcard reader, so can't post up a dummy picture - SO, you have to use your imagination...

Firstly - I'm running the sidemount radiator.

I KNOW that some have run the small renault/VW/Peugeot electric water (booster) pump with front mounted rads and not had any issues (JF + others). Also, the Miglia guys use them with big front-mount rads.
BUT I also know that some have tried with side-mount rads and been not as fortunate. Jimster tried and still had cooling problems. Nic had cooling problems the week before Avon with his new electric water pump setup.
(maybe you guys can add / confirm more info?)

Anyways...
Here is what I'm thinking of trying this week; See what you think. Firstly - I'm going to leave the stock water-pump in place. I like mechanical pumps - they're VERY reliable, and is difficult to forget to switch them on!

I'm considering removing the frontmost core plug at the flywheel-end (rear) of the engine, and replacing with a new core-plug suitable modified with a 19mm pipe sticking out of it (I've chosen this plug as it's high-ish - but not too high - in the block water jacket, and is easy to get to).
I will connect this to the inlet of one of these small booster pumps.

The outlet of the pump will be connected into a new pipe soldered into the top of the radiator. The idea being that I don't want this new water movement to have any effect whatsoever on the flow out of the thermostat housing from the standard pump. Basically, this will flow into the 'air gap' above the water-line in the top of the radiator.

So - My thinking is that this setup will remove the coolant out of the far-end of the block, dumping it back into the radiator for cooling. As the stock pump is being retained, and is only an impellor design, it should easilly be able to 'flow' the increased fluid - as all it's doing anyway is 'moving' the fluid around, rather than pumping it.

I still have my 'heater tap takeoff' on the head connected to the top-rad hose incidentally.

What do you guys think? Any other suggestions? I'm wondering if it'd be better connecting the heater-take off into the pipe between the core-plug and electric pump aswell? Maybe that's something else I can try...




I should point out that I'm really not interested in fitting a front-mount rad, and have already sized up a meziere remote pump (these flow 8times what the best of these small pumps can) but where can i fit one? They're BIG!!!


Cheers all!

Am I being thick? I always thought that the water flowed to the bottom of the rad and came out of the top?

I'm happy to be wrong, but worth mentioning if I'm right.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

the water flows into the top of the rad, and it taken from the bottom of the rad back into the engine. (so the coldest water is taken from the rad)

Dave, I'd be a bit worried about the head not beeing cooled enough as most of the water will simply flow straight through the block and the hottest water will still be stuck in the head.

To ensure water still flows to the correct parts, maybe you could put the electric water pump in the top hose between the thermostat housing and the head,

Team Racing

I would have thought using the heater take off hose connected to a "booster" pump to increase flow from the hottest part of the head may work. Also be very easy to try out. How bad are your cooling problems at present dave?

-MINI CLUBMAN 1380 TURBO-

Dave - I think pulling water from the head at that end would be more benefical than the block- re Jims comments - maybe some work at the heater take off junction? wether this would mean cyls 2+3 running hotter I don't know at the moment

If Carling made Mini engines
it would probably be like this one!

Dave, is there any chance you can post a pic of how your entire water system is plumbed. i say this as you have a water cooled turbo etc increasing pipes and making this topic more complicated.

i have fed the turbo from the heater tap, then into the heater, then back to the bottom hose. i was thinking of fitting a booster pump by the heater tap but i have some concerns how the water flows with the thermostat open and closed.

with the stat shut the water should flow normaly. but with the stat open the water returning to the bottom hose could try to flow the wrong way especialy at low revs when the mech pump is less efficient causing heating problems in traffic

the only proper solution would be to fit the pump in the bottom hose right by the mech pump, but then there would be no point in the mech pump and would the electric pump restrict the mech pump so requiring the electric pump to always be on.

given the turbo engine's low compression cooling should not be a problem. would you not be better fitting a good side rad and an electric fan, then seal the rad to the inner wing and seal the fan couling to the rad?

I'm going down this route too,

I also agree with jims point,

I am enlarging the heater take off so i can run a 5/8" hose to a pump, through the heater and then through the turbo, The idea is that there'll always a nice flow of water through there, Also I'll have the pump connected to a hi boost switch,a manual switch, and also a timer or fan switch to carry on pumping water through the head and turbo after shutdown.

I guess it is possible to go to the point where cyls 2-3 run hotter, I was planing to stick a thermocouple on the heater take of pipe and the top rad hose and see if theres a temp difference between them.

mini13
this is what i was considering with the heater tap, pump, turbo, heater(optional) then bottom hose.

my concern is when the stat is open and the pump running will the flow to the bottom hose try to push the water through the pump AND back up the rad the wrong way since it will also be sucking at the tap end reducing the natural flow through the stat. with the low mechanical pump speed at tick over this could be possible, creating an overheating problem and not curing it.

i would think a low performance electric pump would work, but if using a high performance pump it would have to replace the mechanical pump or be fitted between the old pump and the bottom hose.

Dave
if your using the metro thermostat sandwich plate then things are different. pics and diagram required

Guys, I've discussed my cooling problems once or twice before (!) I recall!

But a picture paints a thousand words....




So
All this started from 2004 when I swapped blocks.
The last engine ran perfect on temperature - never got over half-way between cold and normal. the block was changed - EVERYTHING ELSE WAS THE SAME! Same water pump, rad, head, hoses, etc. Everythign. Cooling problems begin.

I have the stock mechanical fan and shroud on one spacer, and a VERY efficient flat-fan mounted approx 3mm from the rad on the inner wing.

I changed the top-hose to get hot water out of the head and back into the rad. A little better, but not there. I'm using 14mm ID hose to get the water out of the head.

Over 2005/06 rebuild, the block was acid-dipped.

For 2006, I'm no longer running a water-cooled turbo.

For mid 2006 I switched to a 71 degree stat. It's helped things, but still not right - and I know that i can easilly cook it if i drive it hard.




Back to the comments!
Whilst I fully agree that getting the water out of the head might be the better option, it's clear that the head isn't causing the problem. Maybe there is some casting-flash or something inside some blocks that causes cooling problems for the unlucky few?

Either way - If i take it out of the head alone, this will prove little use for when i shut the engine down surely, as by the time the pipe has gone up, then down, it's out of the water-level, meaning the pump will be moving , well, noting?

Maybe connecting the two together is the best way - at least it'll pull water out of everywhere at the far end of the engine...

Dave

problem could be that dodgy looking heater take off pipe.

have you tried putting the hoses back on the right way round?

if you think that the water is sucked through the rad, then at the top hose the water will be pulled from the easyest place. the stat is a natural restrictor and since you have no heater the tap is the easy place to suck from. could the water be sitting in the stat end overheating.

how does your car ever worm up when you always have flow through the rad? the heater tap should go to the bottom hose to prevent water going through the rad before the stat opens?

just my thoughts

Russell

Hmmm, a lot of good points here!

One thing I was thinking about was pulling water from the bottom hose and pumping it into the heater take off, I came up with that one after reading something about water pressure differentials, theres a school of thought where the pump needs to presurize the head by about 10 psi (i think) this is supposedly enough to raise the boiling point to eliminate vapor lock type things.

with this setup you shuldn't get the water stall, ??

the original water pump pushes the water out the heater tap on the head and the thermostat, and sucks it from the bottom hose. what you are proposing is reversing the flow or fighting the original pump

All miglias run the heater take-off into the top hose. I've just copied what they've done - which made (in reality) little difference.
That installation makes sense to me - as the hotter water comes out of the top of the engine (at both ends now) and into the top of the radiator, where it circulates down the core, and into the engine again via the bottom hose.

I don't feel the heater-take-off I have is 'dodgy' Russ? it's 16mm tube (around 14/14.5 ID) and regular 5/8" hose... Only thing it does do is dip-down then up again. But as it's being pumped out of the heater-tap I can't see that it'd cause any problems?

As fluid wants to come OUT of the heater-take-off in the head, connecting this hotter fluid into the cooler bottom hose is surely not the best option as it's putting warmer fluid into the engine - basically circulating it within the block itself?


Fact is - I've got a bad block. As much as I'd like to know why, I'm stuck with this block for the time being and want to make the best of what I have.
That's why I asked for thoughts on the water-pump setup.

I think I'll FIRST try tee-ing the heater take-off into the pipe between the proposed core-plug and booster pump, before throwing it back into the top of the rad. I should be able to borrow an infa-red thermometer from work which'll help point to where is getting hotter aswell...

I can then try restrictors in the pipes from the head or the core-plug aswell - see what difference that makes (it'll help point out where the problem is at least)...

Any other thoughts?

Edited by turbodave16v on 24th Jul, 2006.

Dave
only messing with the dodgy bit and i know you know alot about turbo minis, and yours looks MUCH better than mine.

my thought is that the turbo engine with low compression should not have any real problems with overheating

next thought was if you put it all back to standard, including temp fitting a heater then the problem should go

your current system will increase engine wear as it will stay cold longer as you are efectivly not running a stat as the heater hose goes through the rad.

are you getting a dead spot by cylinder 1 as the water takes the easy route from the heater tap ( normally the heater element will restrict flow) then as a dead spot the water is over heating and the gauge is from that end so could be showing higher than it should

or as you say, you have a crap block! personaly i've never seen a crap block so assume there to be something else. also changing the block is a costly way of finding a blocked hose or something!

Dave, I run a booser pump from the bottom of the side mount rad (alloy Radtec) into a waterpump blank with 15mm hose. Between the booster pump and w/pump blank is a 5/8" hose going to heater takeoff in the head, I have no heater.
I have no problems with this at all. I do use water wetter.
Paul

I seriously doubt it!

Its only really fighting the existing pump if the stat is closed as the pumps are essentially connected in parallel,

Which one are you talking about? Mine? Pauls? Russ's suggestion?

dave,
why not heater take of ,then in a small rad (I used last year a scooter rad with is fan, very efficient), and then if needed in the electric pump to the top of the rad?

That is last on the list Fab! I've got a small motorbike rad and fan (somewhere) in my parts collection. I don't really want to cut a hole in the other inner-wing, but if it gets me through 2006 then i will. :)

Ididn't put in in theinner wing but just under the alternator. it was from a 125 and was very small, but it helped to keep 20° of, running at 70°..I recognise that it was a good casting block that didn't have cooling issues

Pics? :)

On the issues of the back end of the block and head suffering lack of flow, looking at the BMW K head gasket, the water passages are blocked clossest to the outlet of the head and progressively get larger towards the back of the engine, promoting more flow through that part of the engine. Might be worth a try next time some one is having a block skimmed, plug and resize the holes with brass plugs?

Might try this on my next build to be honest.

As for coming off the block core with the electric pump, I think the same as Jimster. I dont think there will be a great deal of flow throuhg the head. It would apear to me, that this set up would short circuit the head.

yeah - I'm in agreement with that - but also want to be able to circulate water on shutdown. that's why I'm considering playing with resrictors - to drag 'sufficient' out of the block on shutdown so as to circulate - and 'enough' out of the head when running....

I guess I just need to get in there and do it!

Hi,
Dave ... I can see how the pump it into the heater take off from the bottom hose would work as it would feed cooler water into the head and it would all flow out of the stat (when its open.)
I can also see what you mean about cooling down after shut off, it would not pull any coolant round either.
However for my money it would be either a scooter rad or heater matrix with the booster pump for shutdown. Reason being the first thing I do if it's running a bit hot it turn the heater fan on, I haven't closed the tap in years, don't think it will!
I believe the heater's a very important part of the cooling system, with the added bonus that if may warm your feet slightly in the cold!
Also the ERA turbos did have an auxilary rad just above the subframe on the O/S this was fed from a sandwich plate under the stat, the return disappears under the rad to.....? HTH
Cheers,
Gavin :)

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