Radiator Mods

[Dale_V]

What advice is that? The fact that someone has run their car for over 3years without radiator fans with no problems? That is not advice it is a statement, no one has advised anyone to do anything they have just shared their experience. I really wish the education system in this country could be improved to help people grasp simple concepts

Dont try justifying poor, misleading and potentially engine damaging information by trying to insult people. You are not the only one with a degree sunshine, the only difference being is that your degree didnt enforce any simple common sense. So yes, maybe the education system should be improved....

[Lauren]

Dont try justifying poor, misleading and potentially engine damaging information by trying to insult people. You are not the only one with a degree sunshine, the only difference being is that your degree didnt enforce any simple common sense. So yes, maybe the education system should be improved....

Is that really necessary Dale? Let's not escalate the debate for the sake of it please.

[richyrask]

An interesting debate indeed. First of all I wont be attacking anyone who has made comments previously I merely want to give my point of view on the subject so as that anyone in the future can make an informed decision.

Before I begin I would like to say I have owned my Mk1 for some 17 years so I know a bit about it, I also have a degree so I think I have a reasonable level of inteligence, although I cant spell. I have also worked for some 20+ years in the manufacturing industry as an engineer.

In my experience in everday use the Mk1 needs a fan of some kind, there I've said it. My car is well maintained has a new radiator and the cooling system is imaculate. I have had quite a few of the pipes off recently for restoration of the outside and internally they are spotless. I have used Forelife throughout my ownership of the car (its not bank breaking but I know a good quality ethelene glycol antifreeze is probably just as good)

IMO the cooling system on the Mk1 is over engineered and at idle, it can take a good 20-30 minutes for the first stage of the fans to come in. I have also had the fans on full a couple of times stuck in heavy traffic, e.g stop start stuff no more than 10mph for a say 10 miles on the motorway.

So if you just track the car and its not idleing for too long, you have good air flow, hey remove the fans save a few Kg that wont make any significant differance to your speed.

Or if you use your car on the road dont mind potentially cooking the head then remove your fans. But I would advise that they are not removed, they do come on after a while and they come on to do a job which is to shift some air through the radiator. Over engineered? YES Not essential? NO Make up your own mind.

[PW@Woodsport]

Well said , a voice of common sense there and bang on the money.

Is a Mk1 cooling system over engineered? YES, it's fantastic at its job.
Are rad fans needed on a Mk1 to stop it overheating at idle? 100% YES.

Removing them is total madness in my opinion.

[Tiamat]

From reading this thread I can see the ultimate question is whether you leave your car idling for long periods of time. 3 hours is an extremely unusual time to leave a car idling unattended. I know what Garrick means though, with most general use you won't be leaving your car stationary for long periods of time, if you were, then you'd switch the engine off.

[PW@Woodsport]

But Malcolm, i've had them overheating at idle after 40-50 minutes (from stone cold) without the fans working, which is sitting in a traffic jam in the middle of summer territory... i suppose you could sit on the hard shoulder for half an hour letting it cool...

So the fans are totally needed, the basic question is why leave them off at all? Where's the gain or benefit? I'm sure i'm not the only one thinking this is madness!

Sorry but nobody will ever convince me this is a good thing to do.

[Peter Gidden]

I have to agree Paul.

I'd never send a car out onto the road without a cooling fan. In fact, thinking about it, i've never seen a thread even suggesting it

[Tiamat]

But Malcolm, i've had them overheating at idle after 40-50 minutes (from stone cold) without the fans working, which is sitting in a traffic jam in the middle of summer territory... i suppose you could sit on the hard shoulder for half an hour letting it cool...

So the fans are totally needed, the basic question is why leave them off at all? Where's the gain or benefit? I'm sure i'm not the only one thinking this is madness!

Sorry but nobody will ever convince me this is a good thing to do.

As I said it depends on the journey you do. If I was sat in traffic for that long, I'd have turned the engine off. I am not trying to convince anyone its a good thing to do, but if you do remove the fans, whether for weight saving or other reasons there is no reason why you cannot run safely, if you pay attention.

[PW@Woodsport]

But that's the whole point, why should you have to pay special attention? I just do not understand this at all. Malcolm will you be removing the rad fans on your car?

If this "mod" is for a track car, then fine, it saves a little weight (although i'd argue if it would make any noticeable difference to a lap time?) and the car will always be on the move and keeping cool, then great, go for it!

However, saying "UK cars do not need radiator fans" is a dangerous statement to make on a public forum. If we are not trying to take 0.01 seconds off the journey time on a public road then someone please explain to me why on earth you would ever consider taking the fans off on a road car?

I cannot understand how this could ever be a good thing to do? In fact like Peter i cannot ever remember reading anything like this on any car forum before.... it's just crazy.

[Rogue]

If this "mod" is for a track car, then fine, it saves a little weight (although i'd argue if it would make any noticeable difference to a lap time?) and the car will always be on the move and keeping cool, then great, go for it!

From a track point of view, we always leave one fan on a car. You *can* get away without using a fan on track since you should always be moving - and moving at a fair lick - so you're guaranteed more airflow than fans will ever provide. However, there was a wake-up call after an MR2 Championship race a couple of years ago when a driver left his fan-less car running in Parc Ferme. It overheated and dumped all of it's coolant, and as a result the car came in underweight and the driver was disqualified. It also warped the head and blew the gasket...

I personally would always run a fan on both road and track cars.

[Steve Horrocks]

If you were that bothered about saving weight on a track car, could you lose the pipework @ rad from front and mount a small deep rad at the side of engine bay? I know on mk1 you'd have to cut a vent hole in side (off side I'm talking here!) but wouldn't this be a massive weight saving over just losing a rad fan from up front?

[greglebon]

Interesting thread....!

I must firstly say to ClarkyX....I only removed my fans cos they were really rusty (twin fans, I must add: UK car, no aircon).
It suited me fine running with no fans, but as Steve said, short journeys predominantly, very few hot days in the last few years.
And, when Steve bought the car, I was under the inpression he was going to track it regularly and was commuting daily.

Based on this, it never crossed my mind to mention the fans were removed: I was aware other people were running fanless, and using the car under similar conditions...?

Benefit of hindsight, I may have misjudged things a little: I got away with it....lesson learned!

To Steve H: the side mounted fan would be good on track...but you would then defo need a fan of some sorts.

The main reason the Mk1 cooling system is SO efficient is the large volume of coolant in the system: putting the rad in the back removes the benefit of this, and makes the coolant system "average" rather than "over-engineered".......so you'll ned a fan!

Comment on something from page 1 or 2:

F1 cars have no fans....so when they are sitting on the grid, they can easily overheat...there are guys with battery-powered fans blowing air over the radiators when they are stationary (and when regs allow! )

I have just fitted a new alloy rad to my Mk3 V6 conversion: this rad is REALLY efficient (Paul will confirm this!).....

But, I will not be removing the OEM fan(s?) from my car this time: the shrouding is in A1 condition, so no reason to remove anything...

Leaving a car idling for 3 hours intentionally is a little unrealistic, surely?
...Especially with the price of petrol these days..!?

I would not recommend anyone removing the rad fans just for the sake of it....based on this debate, surely it just creates another thing to worry about......?

[Tiamat]

But that's the whole point, why should you have to pay special attention? I just do not understand this at all. Malcolm will you be removing the rad fans on your car?

If this "mod" is for a track car, then fine, it saves a little weight (although i'd argue if it would make any noticeable difference to a lap time?) and the car will always be on the move and keeping cool, then great, go for it!

However, saying "UK cars do not need radiator fans" is a dangerous statement to make on a public forum. If we are not trying to take 0.01 seconds off the journey time on a public road then someone please explain to me why on earth you would ever consider taking the fans off on a road car?

I cannot understand how this could ever be a good thing to do? In fact like Peter i cannot ever remember reading anything like this on any car forum before.... it's just crazy.

Paul, missing my point here. What I said was that no doubt you CAN run safely without the fans, not said that anyone should. Also said you would have to pay special attention. That is the point, you have to pay extra attention, that is the set off for it. You clearly don't want that problem so you keep the fans on, which I understand with and I agree. The comment I was making was that the car CAN be run safely without fans, but it doesn't necessarilly mean that you SHOULD run it without fans. It must be a personal decision.

I for one won't be taking my fans off, no. There is no advantage to me taking mine off. Mine is used on the road only, it cannot be tracked so therefore any weight saving would be completely negligable.

On the other hand if they broke, I would not stop using the car, just pay extra attention until they are replaced. As like you, I don't want to have to worry about whether the car is overheating or not and pay that extra attention, I'd rather turn up the tunes, enjoy the sunshine and smoke a cigarette while waiting.

[PW@Woodsport]

I see what you mean Malcolm, and take your point fully.

Why anyone would willingly remove the fans out of choice though beggars belief.... if you want to ditch weight then fit fibreglass doors or bucket seats, they are the heavy items, but please don't remove something that weighs very little and does such an important job.

[Steve Horrocks]

To Steve H: the side mounted fan would be good on track...but you would then defo need a fan of some sorts.

oh yes, totally, meant to add in my original post about keeping fan. Meant more the amount of water reduction would be a greater weight saving than just losing a fan on it's own.

[AdrianS]

My '86 mk1 has factory air (climate control no less!) and two rad fans. They appear to be individually switched : usually ony one of them ever comes on.
Given the 13 or so litres of coolant, it takes a long time to heat soak at idle (imagine boiling 13 litres of water...even without glycol in it) but after about 30 mins of idling in cool-ish (20 C) conditions, the fan will cut in briefly.

Last summer it got a real test, stuck in traffic on a 42 C day (temperature in the sun on black tarmac would have been over 45) with the a/c on.
The temp gauge got no more than a trifle over normal, but I could hear the 2nd fan cutting in quite regularly - I guess 2 minutes out of 10.

Is the cooling system over-engineered ? Maybe for the UK, but we need it here ! Thank you Toyota.

Would I ever run fanless ? No way - why take the risk. If weight is a problem, swap for a modern thermo fan : they are less than 1 kg in the size needed for an aw11.
[edit] As the original poster has done- nice job [/edit]

I know you guys don't have summer as such , but still...

ps I don't have a degree, and am not a mechanic, so I obviously have no right to an opinion , but I have to agree with Paul on this (although not about big brakes for light 4 cyl. cars !)

[jimi]

Wow stirred up a hornets nest with this one

Also, Jimi is a clever guy

don't know about that !
Just wanted to put my reasons for doing the mod down so peeps can see how I was thinking.
My existing fan shrouds were pretty rusty, it would have cost me a fair bit to replace them with new ones (if they are still available)
With the fans fitted you either have to remove the radiator from below or struggle to remove the fans in situ and pull the rad up. I reckoned it would be easier to replace the twin fans with a single slimline lightweight one, and make future radiator replacement easier.
Adding my previous experience with a Fiat X1-9 to my MK1 experience I reckoned that a single fan would be good enough in the UK.
I had read of people running with no fans, but didn't see that as a sensible option for a couple of reasons, one of which has already been mentioned. Long periods of idling or stop/start (traffic jam scenario) movement.
The other reason hasn't been mentioned but I think is probably more important.
All the scenario's quoted make a point of saying that the system will run cool in normal conditions, true but what about when something goes wrong ? eg a small leak causing some coolant loss, or an airlock, faulty thermostat, something your not aware of, you get the idea.
With 1 or 2 fans at least you have chance of the system maintaining normal temps, with out fans .......... little chance IMHO.
So I went with 1 fan and would recommend anyone thinking of removing both fans to think again, as already pointed out the modern slimline fans weigh next to nothing

[Clarky_X]

Greg, I hope you didn't think I was criticising you. I know you had your reasons and your driving conditions were completely different to mine which is why I pointed out the difference.

I hope this thread is now finished, I think everyone has had their say and overcome their differences. I can't stand slanging matches on forums, they make thread unnecessarily long and don't add any value. Just state the facts and leave it at that for future reference.

[greglebon]

No worries, mate: I was just "clarifying"...!

TBH, I was actually planning on fitting a Spal or something at some point...

...trouble is I never got round to it...!