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MG MGF Technical - 2nd Radiator fan

Given the recent glut of threads about cooling and fans, must be the weather :-), I thought I might ask a related question.

On a recent track day I was very surprised how quickly the engine got very. hot. Oil gauge at 12 o'clock. In fact on a few laps with the instructor we ended up putting the heater & blower on full. ~ That was pleasant in 90 deg full sun!

Anyway I have been thinking, if the car is fitted with two fans to cope with the demand of the air-con, why not retro fit a second fan to cope with those very hot situations. Given the number of F/TF's being broken they should be cheap enough to pick up. I must be possible to say add a manual switch using the condenser fan wiring and fuse.

Before anybody comments I know that an oil cooler would be better but I am thinking cheap upgrade.

As you can tell this is at the idea stage, but has anybody been down this line of thought?
Steve Ratledge

I understand your thinking there Steve, and there is a couple of points to make:
1. The radiator fans usually only work when the car is stationary or in slow moving traffic. The amount of air moved by the fan(s) is neglible compared to the airflow through the rad whilst travelling at speed.
2. Your instructer was compelled to turn on the heater and blower on seeing the oil gauge: unfortunately, this would not have a huge impact on oil temperature, but will aid in dissipating heat from the coolant.

So there are two problems here: excess heat in the coolant, and excess heat in the oil.

I suspect that there wasn't a problem with the coolant temperature? If there were, then you might actually be better off ducting the air intake in the bumper to the rad, which will have the added advantage of improving aerodynamic efficiency as well.

Oil temperature is often a problem, and the solution to this is an oil cooler.

There are two types of oil cooler:
1. An air/oil heat exchanger
2. A coolant/oil heat exchanger

The former is the cheaper option, and can be found fitted on the MGF Cup car racers. But the long oil lines to a front mounted rad make this solution less than ideal.
The latter is the oil cooler found fitted to the TF160. It is not necessarily the most efficient variety of coolant/oil heat exchangers - a Laminova is more effective. Happily Laminovas are available for K-series engines - and a kit has been developed for the Elise, which ought to be suitable for the F as well.

So, apologies for the long-winded answer to your question! LOL The answer to your problem is an oil cooler and not a second radiator fan. :o)
Rob Bell

I would not worry about Oil Temperature unless you approach the Black bar at 150 +. The only exception would be if there is a marked change.

My Oil Temp would reach 150 on long hot runs on the continent. This is running Steptronic and Air Con.
An additional oil Cooler cannot be fitted due to the Steptronic and Air Con.

A change to Mobil 1 dropped the Temp at the top end by 10 to 12 Degrees. Mobil specify 200 as max permissible operating temp.

Geoff F.
G. Farthing

>> An additional oil Cooler cannot be fitted due to the Steptronic and Air Con. <<

Why do you say that Geoff?
Rob Bell

Happily Laminovas are available for K-series engines - and a kit has been developed for the Elise, which ought to be suitable for the F as well.

Where can you buy this cooler from please.
Jim Kenny

http://www.thinkauto.com/ (slow server) :(
Had a call with them 2 years ago when we believed an oil cooler would be required.

Or
http://www.elise-shop.com/en-us/dept_8.html
Dieter K.

Rob.
>>An additional oil Cooler cannot be fitted due to the Steptronic and Air Con.<< please read "Air cooled oil cooler".
The Air Con has the Condenser and 2nd Fan and the Steptronic also an Air/oil Cooler with associated pipework. This leaves no space for an air/oil cooler or pipes.
There is not enough margin in the Coolant system to also take excess heat from the oil. Does the TF160 have an increased capacity coolant radiator ??

Geoff F.
G. Farthing

Ah, I understand Geoff - I hadn't appreciated that you were referring specifically to a front mounted air/oil cooler.

Regarding coolant/oil coolers - the standard cooling system is well up to the marginal additional demand placed upon it by maintaining oil temperature.

The reason for the extra fan on air condtioned cars is because of the additional load that is placed on the engine whilst the car is nearly stationary. This is a condition where oil temperatures are unlikely to be significantly above coolant temperature.

Therefore the TF160 cooling system is exactly the same as all other TFs despite the installation of a coolant/oil cooler.

There is no reason why a coolant/oil cooler could be installed on a car equipped with the CVT auto transmission. :o)
Rob Bell

Typical track day ~ nip out do a few hot laps, slow lap to cool brakes etc. In to the pit, leave car running but stationary to slowly cool ~ reduce risk of cavitation HGF etc.

In this scenario I would have thought a 2nd fan was fitted to a standard car would aid the cool down period after a track by helping to dissipate the heat away from the engine block.

PS: what did you mean by "better off ducting the air intake in the bumper to the rad" ?
Steve Ratledge

Steve, in the senario you've just painted, then yes, I could see some benefit: whether that benefit is significant and outweighs the cost of installation I don't know?

>> what did you mean by "better off ducting the air intake in the bumper to the rad" ? <<

Have a look behind the grilles in the bumper. The air is free to move behind the whole bumper assembly: to the sides, and worse, down towards the road. An old trick to improve both aerodynamics and radiator efficiency (you see this on Triumph Spitfires and GT6s!) is to duct the air from the grille to the radiator so that it can't 'bleed' off somewhere else and cause front end lift or not pass through the radiator.

You could use either water proof compressed card material or alloy sheet - the former is probably more crash/crush friendly.
Rob Bell

>> An old trick to improve both aerodynamics and radiator efficiency (you see this on Triumph Spitfires and GT6s!) is to duct the air from the grille to the radiator so that it can't 'bleed' off somewhere else and cause front end lift or not pass through the radiator. <<

And the TF has one of these integral into the bumper design already, so there is a precedent.

SF
Scarlet Fever

This thread was discussed between 16/06/2004 and 18/06/2004

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