Cooling Project

RonnieRover

New Member
You know when you start a job thinking its an easy one and will only involve skinning one knuckle ? Well.......When I got my P6V8, it had an old Kenlowe fan installed on a bracket in front of the rad. It wasn't in the best of condition and appeared to be drawing a silly amount of current so I decided to ditch it. It was only when I finally managed to unfreeze the bolts holding the bracket on that that was going to be the easy part. I ended up draining and removing the radiator and have now decided that I might as well do a couple of other jobs while I'm at it.....so.....here's what I'm thinking :

- Either recondition or upgrade the radiator......any suggestions welcomed here. Aluminium ? 3 core ? Best supplier ?
- New Kenlowe electric fan - single 12" slimline blower to go on the grill side of the radiator....again, any suggestions welcomed here.
- Thermostatic control for fan - I was thinking about the inline version that goes in to the middle of the top hose
- Remove the engine fan
- Re-fill with Evans waterless coolant.....or suggestions on best coolant ?

Any views on the above would be appreciated.....

One other question - I drained the rad with the heater valve open and ran the engine for 30 seconds or so. I see in the Haynes manual that there are drain taps on either side of the block but cannot see them and don't know how to reach them .....any help here ? Does it need to be drained from the block ?
 
At least if you fill it with waterless coolant you will double the value of the car. Seriously though, what is the point ? In about 115 years of water cooled motoring , water, ethylene glycol and propylene glycol , and now the newer antifreezes have proved perfectly adequate , in the case of dozens of millions of vehicles . What you need is proper and complete flushing of all waterways and a radiator which is of correct specification which flows properly. You can probably achieve this, including a re-core if need be, for about the same outlay as the waterless coolant and its add-ons ( scavenger etc ) alone.

I suppose you could also try snake oil instead of 20/50 in the sump !
 
christopher storey said:
I suppose you could also try snake oil instead of 20/50 in the sump !

Don't suppose you know where I could get my hands on some of that, do you? It's probably cheaper than 20/50

I would probably share your view on the Evans coolant, I'm just curious to see if anyone has tried it in the P6 and what the result was.
 
I can't answer all the questions but I can tell you that the car I have just put back on the road doesn't have a fixed fan - just a second-hand Kenlowe with a new controller unit from Rimmer Bros.


WP_20140601_010.jpg by EthelRedThePetrolHead, on Flickr

The man who built the car for me convinced me it was a good idea to have just an electric fan - "it might save a mile or two per gallon in terms of fuel economy" was the sales pitch.

Obviously I never got to drive this car with a fixed fan but I can say that the fuel consumption of around 20-22mpg is very typical for a standard series 2 Rover 3500 - you need an uprated gearbox to make any serious improvements to the automatic V8s but I veer off topic.

The electric fan is set to come on at 85 degrees and it rarely activates, even in slow traffic and hot weather just like it has been in the Uk in the last couple of weeks. The thermostat probe is embedded in the radiator, near the top. The fan also has a manual override switch. The ammeter deflection is barely noticeable when the fan is switched on.

I tend to stick with good local suppliers - Tameside Radiators have served my cars well in recent years and I was greeted like a friend when I arrived with yet another P6 radiator for recore at the end of March.


Tameside Radiators by EthelRedThePetrolHead, on Flickr

They can't/won't recore it to an uprated spec - I ask the same question every time I go and I forget the exact reason they give - I can only adsorb the jargon of so many industries :D

The waterless coolant sounds like a complete rip-off.
 
Thanks Ethelred

ethelred said:
I can't answer all the questions but I can tell you that the car I have just put back on the road doesn't have a fixed fan - just a second-hand Kenlowe with a new controller unit from Rimmer Bros.

This seems to be the best route to take ok. I had an MGB GT V8 prior to the P6 and I tried a few different combinations of fan - the kenlowe was the best. I was curious to see had there been any other options / manufacturers come to the fore in recent years.

ethelred said:
The electric fan is set to come on at 85 degrees and it rarely activates, even in slow traffic and hot weather just like it has been in the Uk in the last couple of weeks.

This is good to hear - I was wondering what difference the engine fan actually made to the cooling. My p6 takes an age to get up to temp(and it's not running rich) , and I'm hoping that removing the engine fan will correct that.

ethelred said:
I tend to stick with good local suppliers - Tameside Radiators have served my cars well in recent years and I was greeted like a friend when I arrived with yet another P6 radiator for recore at the end of March.

We aren't so fortunate here with a selection of local suppliers unfortunately, so may have to send over the water. (Unless any of my Irish friends have any intel to the contrary ?)
 
If you're getting the radiator recored at a local radiator shop, you can get them to add a thermostat switch thread to save having the pipe in your top hose.

Three core radiator will improve cooling i believe.

I've got a 3rd party front fitting range rover fan ready to fit to mine but haven't got round to it yet.

For coolant i'd stick to the standard blue stuff as it's worked fine for at least 40 years. The waterless coolant i havent heard of being used on a p6 so i dont feel we have enough data as to whether it's good or bad. If you havent got an expansion tank though i wouldnt bother, as it's a bit too expensive to be constantly topping up...
 
The best way by far to add a thermoswitch is to have a M22 x 1.5 nut soldered about 2-3" below the top of the rad, below the inlet to the radiator. This is far, far neater and less prone to leaking than hacking hoses and more accurate than external probes. Don't put it right at the top as there can be an air gap.

This allows youu to use a VW (and other) thermoswitch which gives you a choice of temperature points - in fact these are 2 stage switchs so you can use a low/high speed control or a choice of switching points.

Another issue is the fan should come on 4-5 degrees above the thermostat opening point. Use a winter stat (88 degrees) as the finer control should keep it at the optimal temperature more accurately.

Your main challenge is space fitting the fan (see numerous threads). Ideally the most effecient setup is a sucker fan inside.
 
Thanks rockdemon and Peter......

Going to go with standard coolant. The glycol should be fine. Also - Good point on the expansion tank . I don't really have anywhere to put one as the previous minder put the fuel pump and associated bits where most people seem to put the tank.

Going to try and get the rad recorded and upgraded - will also try and get the sensor point installed - great idea.

Will go for the kenlowe - largest one I can get away with

Anybody any idea on the draining taps on the block - how do I get at them?
 
PeterZRH said:
This allows you to use a VW (and other) thermoswitch which gives you a choice of temperature points - in fact these are 2 stage switch so you can use a low/high speed control or a choice of switching points.

does the VW unit come with an adjustable control box? got any photos?

Graeme
 
Nope, but there is a good choice of stats and temperatures (I've seen around 6 variations and this is a good reason to choose something from a large manufacturer with a big range of well-supported vehicles rather than a setup from an accessory shop). Ones for the T25 vans are generally cooler and ones from the Mk 1 and 2 golf are hotter. Of course these are not guaranteed to be 100% accurate.

For example, this would probably be good with the summer stat (82 degrees):
http://www.justkampers.com/251-959-481- ... -1993.html

And this one good with an 88 degree stat:
http://www.vwheritage.com/vw_spares_The ... 543547.htm

The upper temp is the "on" temp and the lower the off temp to stop the fan flapping on/off. There is an overlap, so effectively you'll have coolant at a lower temp in the rad ready for the thermostat to let through on the next cycle.

Also as the temperature is more tightly controlled you'd ideally run the car at a warmer but consistent temperature (but still a fair bit lower than the last of the factory engines which were ran too high for emissions reasons and this affected reliability). There should be no more dangerous spiking upwards in traffic, so you really want to maintain 90-95 degrees and not the low 80s. The V8 certainly runs noticeably better in my view and it's impossible to run it in this optimal window without electric cooling. Keep it below 105 degrees in the extreme and you won't have any warping problems.

As for a speed controller, use a simple resistor pack (0.28ohm I think) from something like a Ford focus.
 
PSA group thermoswitches are the same thread too (M22x1.5) so you have the choice of every Citreon and Peugeot from the 1980s and 1990s.

Oh, and just checked Ford and GM too - so basically everything that moves.

So take your pick, no need for the other f-ugly solutions I've seen and spares are plentiful and cheap. Cost me 50chf (£30 but you can lower that for anywhere else on the planet outside Switzerland) to have the brass nut soldered in.
 
Interesting thread this. Since Bruiser's post-accident return to the road, I'm running a standard rad' as the three-row got too bent out of shape (even though it still worked & was leak-free). With the hot weather, M25/North Circular queues have been kept under control pretty well by the electric fan in the mid-upper reaches of the temp gauge. I've been wondering whether it was worth getting another three-row made up but I probably will & I'll have a nut inserted to take a switch for the fan too.
Where would the optimum four-pot temperature ranges be?
 
Mid-upper green range seems ideal to me. Easy to measure accurately if you have or can borrow and IR thermometer (read off the stat housing). Mine was £10 from Aldi and is really accurate. The only way to test cooling capacity is find a really hot day and park the car with the engine running and see if the fans cope. If you are moving at all you have a massive amount of cooling - it really is traffic that stresses cooling, no matter how sporty you think you drive.

Optimum temperatures ranges for most engines of that era are all around 90-95 degrees. Modern engines run up to 110 degrees or so without problem. Later V8s try and run at this temperature but that was one of the reasons they were unreliable.

You have to remember that conventional cooling works almost opposite to what is actually useful. When moving you don't need any fan (but get it anyway as the engine revs) at all as airflow takes care of the heat. In traffic when you need cooling most you get none of it as you idle.

So in effect on the move if you use a summer stat (82 or even 78), then engine is almost always too cold if the rad is doing its job, this is bad for efficiency and emissions BUT it allows enough overhead to try and avoid overheating. In traffic you are up to 110-115 degrees which is why cooling systems are pressurized. So basically the worst of all worlds and extreme fluctuation.

Basically using electric cooling you become like a modern car - goes to the center of the gauge and doesn't move so the engine operates at the best temperature for more of the time. To do this you need to run the winter stat to keep the temperature up BUT have enough cooling capacity to respond to any increases over and above quickly as you have less overhead in hand. This is one reason why you'll see quite substantial radiators on quite modest cars today. It's about efficiency (running hot but not too hot) and the flip-side better emissions (and to allow for the load factor for aircon, PAS, large alternator etc.)

This is where your uprated radiator and cooling fan of sufficient capacity come in. However as a P6 is much less efficient than a modern car which will run leaner and hotter and burn the fuel more completely you'll generally need less cooling (as your expensive energy disappears unburnt through the exhaust!) than a modern car of similar capacity.

Advantages?

Well warm up is said to be one but this shouldn't really be the case because of the thermostat. What might help warm-up a bit is less secondary cooling i.e. airflow around the engine (remember the grille covers for winter). You should get better mpg through not having the fan on the engine AND running always at the right temp. A tighter operating band should reduce engine wear a bit. Emissions should be better. Engine will be quieter and idle smoother. The heater will work better.

Implications?

Well might want to consider the oil grade you use and use what's recommended for hotter climates. It might increase fuel vapourization as less air around engine.

But generally a win.
 
As far as I am aware, the only benefit of waterless coolant is that it expands very little and so does not pressurise the cooling system.

This might be a bonus on a racing car when you might be working on a hot engine, but probably not needed on a road-going vehicle.

I use an x-fan on my landrover, and that provided an easy solution to the problem of electric fan switching without having to modify the rad. I haven't fitted one to my P6 yet as I still need to measure the ID of the hoses...

http://foundry4x4.co.uk/index.php?route=product/category&path=65_1760

I am using a fan from a Discovery, which I manually switch. My fuel consumption has been pretty good.
 
Someone has been asking about the waterless coolant for the P4's on another site. Apparently, an engine-full is £170. :shock: Good luck with that, especially if you suffer a split hose on the move.

The emperor's new clothes springs to mind. :roll:
 
Sounds like a good one to have if you are into " Pub Trumps" with your mates.

I can picture the brinkmanship between......

" I've got Nitrogen on my tyres" ......

AND

" I use waterless coolant in my car" ......
 
I've heard of waterless coolant and those that use it in australia using classic cars doing a charity drives through the outback etc, where temperatures can get up to high 40's so it makes sense in that respect, and looking on the website the 'science' is pretty convincing, and as the cooling system operates at a lower pressure then split hoses would be virtually eliminated (if changed regularly) not that I'm plugging it, but not dismissing the concept/product either, I may consider it when my (expensive) engine rebuild is at the 'filling with coolant stage'. It would be interesting to hear from any forum members who have used this product and get some feedback. As mentioned above cost is a big factor seeing as they reccommend getting rid of any residual water using a prep fluid (39GBP for 5litres of prep fluid)
Scott

http://www.google.com.au/url?url=http:/ ... TPGbBjlcpw

http://www.evanscoolants.com/evans_wate ... lants.html
 
Update on my original post :

- Have gone with a Kenlowe 13" High speed fan. Managed to fit this without any mods - required removal of the radiator. It's a tight fit but does actually fit and operate ok. Draws a lot of current and had to update fuses etc. On the advice of the guys in Kenlowe I just connected up the high speed circuit.
- Drained and flushed the coolant system and renewed the coolant with 50/50 coolant and water - didn't bother with the Evans waterless in the end
- Removed the engine fan and have experienced what is probably a placebo of more bhp !

Glad to say that all is working well - have to say that the cooling system in these cars is pretty good. The addition of the fan will hopefully take away that traffic stress.

Thanks for all the posts and help.....
 
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