Eleven bladed fan

D

DOC

New Member
Hi all
Does any body know where to source an eleven bladed fan as mentioned in this months mag by Andy Gordon as one of his modifications.
Or does anybody know how I can contact Andy to ask him.
As it seems that this may solve my problem of very slight temperature rises when in slow traffic.
I don't feel that my problem justifies a full blown Kenlow.
Any advise would be gratefully received.
DOC
 
Hello DOC,
if you contact our editor she may well pass on your contact details to Andy so that he may contact you.
A "very slight" temperature rise is inevitable in slow traffic so I wouldn't consider that to be a problem.
If you ever get stuck in traffic and have to pull in to the roadside after 10 minutes or so then I would think you may have a cooling problem and a radiator re-furb and the fitting of a Kenlowe is highly recommended.
Another advantage of a Kenlowe (or similar) is the option of removing the standard fan altogether to add another couple of hp output from engine.
Hope this helps.
Regards, John.
 
John is right to promote the worth of eliminating the engine driven fan with a Kenlowe (or similar). In the 60's car manufacturer's struggled with a difficult problem - The most arduous conditions for the cooling system are when standing at idle (or very low engine speed) in traffic (round of "Here! Here!" from p6 owners). A radiator fan sized to be adequate in these conditions will then continue to absorb more and more power as engine speed rises, even though "help" with the air flow through the rad is probably unnecessary above about 30 to 40 mph. (my science memory reckons the power consumption goes up logarithmically with engine speed - anybody got a textbook handy?) Net effect is that at high engine speed the fan can be leaching away up to around 20bhp. In the 70's this was tackled to some extent by fitting fans with a centre incorporating a hydralic clutch designed to slip at a certain torque and so save the fan from doing too much unnecessary work. (I think very late V8's got these? certainly SD1's had them from launch) This is purely engine speed sensitive though and doesn't take account of when no additional air flow at all is required through the radiator. Hence the move on again to electric fans triggered by the coolant temperature. No modern car at all is fitted with an engine driven fan any more!

Of course, you might not want any more power from your V8 (I'm afraid I'm with Jeremy Clarkson here - no amount of power could possibly be too much - it's how you use it that counts!), but I bet you'd appreciate spending less money on petrol! And of course, if you're doing unnecessary work with the fan, the engine is unnecessarily using extra fuel! Ergo fit electric fan - use less fuel. (and less waste heat for the radiator to get rid of and less wear and tear etc etc - a virtuous circle - Colin Chapman would be grinning from ear to ear)

Only hazard to watch out for is that you potentially need a bigger alternator because you've increased the potential maximum current draw of the car. (note the battery is quite happy still - all it has to do is start the engine and that duty is unchanged - unless something else is wrong somewhere else in the system!)

I've only got experience with one car where I've eliminated the engine driven fan in favour of electric. That was a 3 litre MGC and it completely transformed engine response! The car was much more pleasant to drive; they had a justified reputation for being rather half hearted and strangulated at high revs compared to the Healey 3000 and this completely fixed the problem. I was too young to notice the effect on fuel consumption - I was getting under 10 to the gallon thanks to a size 14 right foot!

Many people supplement the engine driven fan with a Kenlowe - this gives the worst of all worlds - the engine driven fan is still there leaching power and now you've added the potential difficulty with electrical capacity for no gain!

All the above presumes that the size of the radiator was adequate to start with! The normal test of this is whether it can withstand a cross Europe high speed run in the summer! British cars were notoriously under - radiatored by this standard and P6's were no exception. Since with motorways and climate change we effectively have those conditions in England today without needing to pay for a ferry crossing; it follows that P6's, even in 1st class mechanical condition, are a bit marginal in modern driving. Normal solution is to have the radiator recored with an extra "row" (ie 3 row) or "continental" core. This is a very marginal extra expense once you're commited to a new radiator anyway. Talk to your supplier to make sure the cores are arranged to give the best possible airflow through the rad - they sometimes build them with the cores staggered and masking each others air passges.

The reason radiators were undersized was of course to save cost and in particular weight in the days when radiators were made of copper. Alan Ramsbottom at Chassis Parts has built Aluminium radiators for the racer and other customers which also has the benefit of eliminating dissimilar metals in the coolant system.

Hope that all helps.

Chris
 
I agree with all the above, but would just add that if you have an auto, have the new rad made without the trans cooler and fit a seperate one with a thermostat, thus avoiding the extra heat going into the rad, and any chance of coolant getting into the transmission.
 
DOC,
I knew that I could rely on Chris to supply a comprehensive answer here after hearing of his P6 cooling problems in a hotter climate!
Chris, I had read in a practical classics type magazine many years ago of the mechanical cooling fan absorbing 2 - 9 bhp although that was almost certainly a a 4 cylinder engine of less than 2 litres capacity so 20 bhp on a 3.5 litre or larger sound feasible!
Regards, John.
 
hi doc,
to answer your original question, andy gordons car was mine originally, a fully re-built NADA copy in RHD form. being a NADA copy it had every thing on that they had on them in the states and the 11 blade fan he is on about was standard fitment, it is a form of plastic and runs off of a viscous unit on a slightly different water pump to a standard V8 also a lot smaller pulley. to go down this route is expensive, you will need the 11 blade fan, viscous unit, water pump, pulley and new belt. i did do this on the car and it is excellent, stood in traffic and the gauge never shifted, i have sold two more to other people and they have reported the same. it was designed for the american market with there hot climate and does an excellent job.

ian
 
Hi Ian, all the parts you mention are listed in the parts book. Do I remember that they were also fitted to the end of line VIP cars?
 
Just to throw my experiences into the equation!

Erik's radiator sprung a slight leak this summer, so I took my spare to my local radiator specialist, for a rebuild. It cost 90 quid, including VAT. Since fitting, the car has run a lot cooler, and doesn't creep up so fast when stuck in traffic.
A little trick if you do get stuck in traffic, is to put the heater on full blast. Not pleasent, but it does get rid of some heat!
 
I had a 3-row radiator fitted to our P5B when we restored her, a Kenlowe on a switch (the thermostat never worked) & removed the standard fan though I never noticed any difference in engine response. Under normal conditions the kenlowe was never needed but in traffic the temperature still headed for the red after a while, all the waterways were cleared when the engine was rebuilt. Last time I used her I replaced the standard fan but I'll experiment again when I get her back on the highway.
 
Hi again ian, I thought they were, at the time they were released to the dealers, (each dealer had one I recall) it was the hottest summer on record, 1976(?) and I was working in a Rover dealers and changed both the head gaskets on the firms VIP. After the job was done, taking the car for a road test thru the traffic with the a/c on full blast the temp held firm, no problem at all. I remember thinking "why does everyone look so hot?" It was only when we got back and stepped out of the car, it was like stepping into an oven! I shouldn't there's many VIP's left now out of that 144
 
hi john,
yes you are right, i don't know where i got double the number from.

ian

and NO there are not many VIP's left, they were rotten before they left the factory as most of them were stood around before british leyland decided what to do with them.
 
Not only that, I think they were painted on the SD1 line and the quality control was terrible (non existant?).A lot of the ordinary late P6's had similar paintwork problems developing great big rusty blisters all over, and ally corrosion coming thru on the bonnets and boots.
 
Just a quick question regarding Kenlowe,i have seen them often but never fitted one to date although i am contemplating it now.The trouble is that the fan surround looks as if it's almost cable tied to the radiator for universal fitting of which i would not do on principle,so fitment is a issue for me as is the location of a thermal transmitter ( from memory a wire of some description inserted in say the top hose,then linked up to the adjustable stat for control...i think) would a better and neater solution would be to replace the stat housing on the inlet manifold in place of a later range rover housing which incorperates a proper thermal transmitter (sender) screwed into the top...not sure at what stage the new transmitter would switch accross and also how to retro fit the wiring to do it this way....has anyone done it this way? seems more logical to me
 
rich j
regarding fitment - the Kenlowe kit I purchased for my Three Thousand Five had two brackets that bolted through existing holes in the top flange of the front valence.
I didn't use the thermostat / switch, preferring a manual on/off switch.
Hope this helps.
Regards, John.
 
John, a manual on/off switch is ok if your keeping the standard engine fan, but if not you're liable to let the thing overheat before you notice and switch it on !

I used a Citroen BX fan on my 2.2TC, fitted in front of the rad, and removed the engine fan, loads of room between the engine and rad !
 
Hi all...done my homework regarding the Kenlowe....the 12b Kenlowe is the suggested unit for all P6B..this a blower type fan which sits between radiator and grille.There are no clearence issues and new style clamps are substantial and look like a quality product for hanging the fan unit,also no requirement for upgrade for alternator for this fan.Unfortunatley the wire thermal transmitter remains the same but kit supplied ensures of a good quality seal within the top rad hose.Guess i will figure out a more attractive fan switch arrangement..
 
You just need a temperature sender unit with a similar resistance profile to the kenlowe sensor, use a multimeter and a bowl of warm water to test.
 
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