Morris Minor Owners Club

Les, I use the standard sidevalve cooling fans attached to the dynamo, which are smaller than the later overhead valve fans, and have no cooling problems. I do have the benefit of the slightly larger sidevalve radiator.
I can give you some advise on set up and running Shorrock, Judson or Arnott superchargers, plus I can offer compressor service/rebuild services (when I can find time!).

regards Keith

For use when idling in traffic - they move enough air to keep the idling engine cool - but no-where near enough to cool a hard working engine - especially if s/charged. Stand beside a Mini - and get the driver to rev the engine - the absolute GALE of hot air that flies out from under the wing will explain what's going on.

Well, a car at standstill with a supercharger will naturally create plenty of hot air. When on the move the air forced into the Minors enginebay will go some way to reducing this, the fan will do the rest if it has been selected correctly.We have many trackday cars out on the road and track which are easily cooled by electric fans. As I say the best way to reduce underbonnet temp is to allow the air to escape, through louvres or the like. Kenlowe worked with us on the choice of fans to cope with both road and race conditions, and I'd be the last person to question their knowledge and experience.

Thanks Keith, Will keep your post to hand, would be glad of your opinion on compression ratio, and if balancing the bottom end would be good idea etc.

Jonathon - I'm sure your electric fans won't be running when the cars are moving at speed. My research is from 40+ years of working with cars - University of Life. The original Q was about sufficient cooling - I suggested using double fan blades would be sufficient - I stand by this. Worst case would be slogging up some mountain pass - engine working hard, not very much ram air through the rad - need to keep a good volume of air through the rad with a fan. Normal leccy fans are not designed for that service. I do agree it's necessary to let the hot air out - but the Minor is not too bad in that respect with two nice big air vents at each side of the engine bay.

I'm sure your electric fans won't be running when the cars are moving at speed.

Not if the temperature level is below that of the fan thermostat, I always though that mechanical fans absorb power and are noisy compared to an electric fan which are designed to allow faster warm up and higher operating temperatures and therefore are more efficient, also their size is not the key but the volume of air they can move and they come in push or pull versions to suit the relevant application also their speed is not goverened by engine RPM so the efficiency must be better and they can even be fitted with manual controls if wished.

Absolutely - for a normal car excellent idea. This Q was for a supercharged car - possible cooling problems. I suggested a very simple and inexpensive (as are all my suggestions!) way to improve the cooling if found wanting. It's turned into a smashing big long thread though!

but quite interesting though

Well the proof that there is no problem has been given by Keith. As Kevin states, the fans only come on when the fan swith, adjustable stat or ECU sensor tell it to. When they or it are activated then they will be more than effective, our two 9" fans provide over 1200 cfm. No doubt the BM route might be enough, and is certainly the cheap option. I'd rather vent the bonnet and rely on good electric fans.

jonathon wrote:our two 9" fans provide over 1200 cfm.

Hmmmm... That means one fan provides just over 600cfm - And many engines are fine with one fan.

And I have a box full of 12v computer fans, some of them are specced to around 70cfm.

So I could save money and tie 10 or so to a radiator

Hey, now there's an idea, why didn't I think of that. Put then all in line attatch to the inlet manifold and hey presto BM styleei supercharger

I've wondered about fitting computer fans in line to the demister (a little off topic I know) to give it a boost!

jonathon, Hi Jonathon.
Could you please let me have details of the rad that you mentioned to bmcecosse. Are they suitable for my standard Ital 1300 engine.
I really fancy the idea of fitting a more modern type rad with a higher presssure cap and a feed/expansion tank.
Cheers Slugger.
My e-mail address is doug.batber@zen.co.uk

Modern cars use very thin aluminium 'radiators' - in fact they 'radiate' almost nothing - and would be better described as heat exchangers.
I think J's point was that they fit twin electric fans to whatever rad they are using. Not a cheap option - if buying the parts new! Many good rads complete with leccy fans in your local scrap yaerd! But for most Minors the standard radiator is more than adequate - it's almost twice the size of the rad fitted to a Mini with the same engine! Years ago when traffic wasn't so heavy I never had any fan on my Minor - but these days with traffic jams everywhere I would say some form of assisted air flow is necessary - I do like the 10 x computer fans idea!! Might make the car a bit nose heavy.

I think J's point was that they fit twin electric fans to whatever rad they are using.

Not really, we use a single 10" fan with standard, K series, Zetec or Fiat,etc along with our alloy radiators. Modified motors often require two 9" fans and alloy rad. Standard or modded A series Minors are okay with the standard set up, however an electric fan instead of the standard one will liberate a small amount of power. Not cheap I grant you , but sound practice.

Sorry for the thread resurrection.

Just reading through this one as I have been asked to research rads by the old man.

Seems he ("Slugger"- why, Dad?!) asked the question some years back. See 3 posts above.

Any thoughts on his question about new radiator? I doubt he ever got an email, as he got his address completely wrong, bless him!

Thanks,

David.

We have a single 9" Spal 'pusher' fan in front of the radiator and a thermo switch in the header tank. The rated flow is 740cfm, and certainly enough to cope with anything required by our 1380 in any temperatures or conditions experienced so far - temps up to 40°C. It just cycles on/off in traffic. The standard Minor radiator was re-cored about 5 years ago with a modern close finned element and the header tank neck replaced with the more current 'short' type where there is a greater choice of cap pressures. It is fitted with a 10lb cap, just for a bit of extra security. The experiences below were with the original standard Minor rad.

With the original modified 948 we had no fan, and the first 'low cost' version for the 1380 was an OEM fan from a 'modern' in a breakers yard, again arranged in front of the radiator, with the same thermo switch and off to France a few weeks after the restoration was completed. All fine, temperatures up to 35/40°C and worked perfectly, until the fan failed! The switch was fine, just the fan motor. So on went 2 standard Minor blades at 90° and yes the cooling was fine, but the NOISE!! Horrendous, even with a 5-spd box and cruising at 3,500/4,000 rpm it was awful. So as soon as we got back I researched electric fans and found the Spal, which at just 2" thick goes in front of the rad beautifully. That was nearly 17 years ago.

A note of caution about positioning the thermo switch. We once lost water through a leaking heater tap and of course the temperature went up as the level went down, but by then the thermo switch was no longer in any liquid and saw no problem, so no fan cut-in - hot air does not work the same way as hot liquid. The same would apply to the top hose switch location. I am already using the head tapping for the temperature gauge bulb, so where else could the thermo switch be installed?

Postby jonathon » Sat Oct 20, 2007 8:28 pm
I think J's point was that they fit twin electric fans to whatever rad they are using.

Not really, we use a single 10" fan with standard, K series, Zetec or Fiat,etc along with our alloy radiators. Modified motors often require two 9" fans and alloy rad. Standard or modded A series Minors are okay with the standard set up, however an electric fan instead of the standard one will liberate a small amount of power. Not cheap I grant you , but sound practice.

Postby jonathon » Sat Oct 20, 2007 8:28 pm
I think J's point was that they fit twin electric fans to whatever rad they are using.

Not really, we use a single 10" fan with standard, K series, Zetec or Fiat,etc along with our alloy radiators. Modified motors often require two 9" fans and alloy rad. Standard or modded A series Minors are okay with the standard set up, however an electric fan instead of the standard one will liberate a small amount of power. Not cheap I grant you , but sound practice.


Hi Jonathon
The liberated power only occurs when the elect. fan is switched off. When switched on, assuming it moves the same amount of air as the mechanical one it will consume about 15% more power from the engine via the generator or alternator. This is because the efficiency of the generator/alternator and fan motor is only about 85%.
Cheers Bob

"When switched on" is very rarely, almost never when the car is moving.