28 replies to this topic

[Keith1948]

I want to fit an electric fan to my Mk1 Cooper S classic inside the near side wheel arch is it possible  and which one would be best. 

[IronmanG]

Talk to David at wired by wilson. Good quality and value for money.

[stuart bowes]

just gonna hijack this thread because I was actually going to post something on this topic anyway

 

can someone explain to me why the electric fan gets put under the wheel arch...

 

the way I see it, right, you're driving along and the cool air comes in the front, the engine gets hot obviously but because of the supply of cool air, a sort of aggregate 'warm' air ends up getting pushed through the rad, effectively cooling the engine to some extent (it works, but it's not really the ideal setup,  presumably why they moved the radiator to the front and made it bigger later on)

 

 

so, then you stop, and the heat builds up because you lose the cool air in from the front, heat builds up under the bonnet and now you're pushing hot air through the rad.  not good

 

 

having the electric fan under the wheel arch helps I'm sure, but only because it's moving that stationary hot air faster than usual to get more heat out 

 

Am I just totally stupid, or would it not be better to put an electric fan on the front, like this

 

 

effectively simulating the input of cold air as if driving along.  the heat will still build up to a degree obviously but you're creating an area of cold air near the radiator, the standard fan then pushes that through the rad, and you're cooling things down

 

or.. both on the front AND under the arch, it's not like they're heavy or anything..

 

willing to take on board any opinions to the contrary..

Edited by stuart bowes, 09 April 2024 - 04:46 PM.

[nicklouse]

Stuart you are missing the bit about the extra fan being ducted. So it pulls air through the rad. Also the wing area is actually hard to get air to flow through it putting one on the front will help but not as much as the mech fan will only really blow the same volume of air. The excess air blown at the engine will escape by the easiest routes. Not necessarily through the rad.

[stuart bowes]

well that's a fair point I did have in mind some some of directional ducting to improve on that, but space is obviously is at a bit of a premium

 

the ducting on the under-arch fan may improve the air flow, granted, but it's still pulling hot air, that's what I was thinking of trying to improve on

 

I did even think two fans, to fully replicate the driving conditions 

 

 

but would that not make any additional improvement, and would it restrict airflow in normal conditions

 

what I don't really want is any sort of bonnet venting because that would look a bit naff I think.  although what they did with Binky louvering the scuttle panel was a nice idea

Edited by stuart bowes, 09 April 2024 - 05:10 PM.

[Quinlan minor]

The following applies to side-mounted radiator equipped Minis.

The principal purpose of a wing-mounted fan is to draw air across the radiator, increasing the transfer of heat from the coolant to the ambient air.

 

The majority of air from a front-mounted fan would exit via the bottom of the engine bay, or back out through the grille, when stationary.

A much easier path for it to take than passing through the radiator into the wing.

Surprisingly, those car designers, knew what they were doing.

[stuart bowes]

but then, by that logic, that's what happens when you're driving along as well, no ?  admittedly the difference being the air flowing under the car adding a sort of upside down chimney effect to aid cooling

 

not sure i'm completely convinced by the 'knew what they were doing' argument, I think the driving force behind the layout was that the engine was transverse, so the fan ended up where it was, therefore the rad had to go where it went

 

and let's not forget they were trying to save money as well..

 

so actually it may be more a case that they would have preferred it a different way, but it 'worked' (in those earlier days of less traffic on the roads) and they were constrained by other factors 

Edited by stuart bowes, 09 April 2024 - 05:47 PM.

[Quinlan minor]

The engine mounted fan pushes air out of the engine bay through the radiator. The ducting is important in achieving this, ask anyone who's tried running without ducting.

However, the engine mounted fan has to strike a balance over the rev range. It's especially inefficient at tickover, in stationary traffic, hence the advantage of a supplementary wing-mounted electric fan.

[stuart bowes]

No I understand that, the point I'm making is, when you're sitting still, you're pulling hot air through the rad. yes I'm sure to some degree that is an improvement over the slow moving belt driven original at tickover

 

whereas on like 99% of other cars the fans are there to pull fresh air in through the rad from the outside (front mounted rads though, obviously)

 

I'm saying it would be better if there was a supply of fresh cold air instead (or, as well)

 

now obviously you can't blow air in from the side because it would counteract the effort of the original fan, so do it from the front 

 

if you're arguing that the effect would be a minimal improvement then fair enough I don't have the means to test or calculate otherwise lol 

Edited by stuart bowes, 09 April 2024 - 06:03 PM.

[Quinlan minor]

I'm saying it would be better if there was a supply of fresh cold air instead (or, as well)

If you pull air out of the engine bay, it will fill with fresh air through the grille, as long as either fan is running.

Nature abhors a vacuum.

[bangermadness08]

what i have noticed is the prices of addon electric fans. for a 10inch fan bought from ebay cost about £20. Mini spares nealry £80. as i can see both are the same, and the electric fan would only come on when needed. 

 

i got wired by wilson to fully install mine swapped the old spi to after market one and notice a difference to running temps etc.

[stuart bowes]

 

I'm saying it would be better if there was a supply of fresh cold air instead (or, as well)

If you pull air out of the engine bay, it will fill with fresh air through the grille, as long as either fan is running.

Nature abhors a vacuum.

 

 

that is true, in the same way that my computer would draw air in from the holes in the back and top, when the fans suck air out through the radiator at the front

 

but it still made sense to add fans to the back and top, to push more air in .. again is that more or less effective than it would be without them, I suppose I could turn them off and monitor the core temperatures, but in that example at least the fans are so cheap it really just seemed daft not to

[Quinlan minor]

 

 

I'm saying it would be better if there was a supply of fresh cold air instead (or, as well)

If you pull air out of the engine bay, it will fill with fresh air through the grille, as long as either fan is running.

Nature abhors a vacuum.

 

 

that is true, in the same way that my computer would draw air in from the holes in the back and top, when the fans suck air out through the radiator at the front

 

but it still made sense to add fans to the back and top, to push more air in .. again is that more or less effective than it would be without them, I suppose I could turn them off and monitor the core temperatures, but in that example at least the fans are so cheap it really just seemed daft not to

 

Unless you've got a watercooled processor you're comparing apples to oranges.

Air-cooled engines are a whole different ballgame.

[stuart bowes]

I do have liquid cooling, the GPU was causing in-case temperature issues, to be honest the main difference really isn't the type of cooling so much as the fact that the radiator can be located remotely which means heat rising from the GPU isn't being absorbed by the heat exchanger

 

regardless..  the process of hot out, cool in, is still comparable, what we're comparing now then is letting the 'vacuum' such as it is draw in fresh air, vs. pushing it in more forcefully 

Edited by stuart bowes, 09 April 2024 - 08:25 PM.

[Midas Mk1]

Inner wing fan mounted on outside on inner wing wins hands down, means no clearance issues fitting the rad, and no access concerns if you fitted a front fan (that wouldn’t be any where near as efficient.

No need for an expensive ‘kit’, wired correctly with relay, a low cost fan with switch mounted inside is great on a hot day in traffic. Make sure it’s a decent ‘pull’ fan, with good cfm.
Plastic mechanical standard fan is most efficient in standstill traffic and slow moving traffic over an export spec fan, i’ve tried the small, large pulleys, settled on a happy medium of MED middle sized pulley, seams to be the one.

Speaking from experience not hypothetically, daily driven for over 10 years.

Edited by Midas Mk1, 09 April 2024 - 08:32 PM.