Electric fan

[floyd]

Hi all, I'm about to replace my knackered viscous coupling and fan and wondered if I'd be better of spending the money on a 16" electric fan mounted in front of the radiator instead. I've read the SOC tech file on cooling and it seemed to suggest that this might be the best way to go. So has anyone gone this route and do we think it's the right thing to do?

Thanks,

Floyd.

[brian0443]

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Good morning Floyd.

There has been a lot written on this topic. An electric fan may well give you all the assisted cooling you need if your Stag is in good order and not prone to overheating. That would be your choice. Don't lose sight of the fact that the standard fan running properly moves a lot more air than even the biggest of the electric ones. My Stag came to me with both. Even in yesterdays weather, 23c here, the Kenlowe did not kick in whilst driving and the guage only wavered slightly towards high in heavy traffic. Its great to know that I have a backup system.

Brian

[EFI Stag]

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I replaced my engine driven fan with a 16 inch kenlowe on my last triumph engined stag had no problems.

There was a previos thread in May about kenlowes

hope this helps Martin

[whereufromnosecity]

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Hi Floyd

I fitted an electric fan and a header tank last month and had no problems since, they are very simple to fit and wire up, if you buy 1 which attaches to the radiator through the core i would recommend making some brackets to mount the fan.

Stuart

[robertt1948]

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Hi Floyd,

I fitted a Kenlow to my car but I think you should replace your viscous fan coupling first. I've never checked it but I would guess the engine fan shifts more air than any electric fan. Pity the engine fan is solow down on the rad. Bottom part of it misses the radiator and the rest of the fan is sucking through to coolest part of the core.

I never had much luck with sealing the capilliaryinto the top hose and I don't like gobbing things up with silcon sealant. So I held the temperture sensor bulb against the top hose, wrapped a piece of pre-formed foam insulation around both and secured with tie wraps. It's not necessary to control from the true temperature of the water because the controller isn't scaled anyway. You just need an arbitrary set point.

I fed my fan directly from the battery through a fuse mounted next the battery terminal. The fan will cool the engine when you've parked up and switched off.

I have turned the controller virtually to the minimum setting. Two reasons. One because of the position of my sensor outside of the hose and two because I like the fan to come on at only just above normal running temp. I think most people set them to come on when the engine gets very hot. I think your better not waitng that long.

Consequently, my engine runs at its coolest in standing traffic even on boiling hot days, like this weekend.That's because I never let it get hot before switching it on. Why wait until you're about to overheat before it comes on? The only time my engine gets warms is at constant high speed or when negotiating long gradual inclines on a motorway.

Hope my ramblings may be of some help.

Best regards

Robert

[SwissSteve]

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I have a couple of questions on the Kenlowe fan.

I was expecting my fan to come on during this hot weather but it did not regardless of if I set it to C or H. How do you test these fans to see if all is ok?

I was also thinking of fitting a bypass switch on the thermastat so I can control the fan from inside the car. Shound I fit a relay or is a 20A toggle switch ok for this purpose?

[Paul Goldsmith]

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Floyd,

When I had my viscous replaced last year the improvement in cooling was simply stunning, no other word for it (despite our couplingnot making any noise andbeing only slightly slack in the static test, indeed a previous garage had ruled out any need to replace it on this basis previously).

I now of the opinionthat working well the Stag cooling system is adequate but only just, with minimal tolerance for any deficiences.

We'vestabilised our cooling on the standard setup, having also reverse flushed our block & radiator, plus installinga tested thermostat of the correct spec which for us means a bypass foot and jiggle pin, with the latter installed at the highest point.

As an alternative to fittingan electric fan I'm about to fita repro tropical spec radiator cowl (from Glenn Merrill) whichshouldprovide additional performance at stationary and low speeds, this was identified as very effective in the mid '90s SOC cooling comparison tests. There's been a recent superb topic on this forum which hasused a modified secondhand Mercedes cowl to similar effect, you might reviewthis as a much cheaper option to either a Kenlowe or repro cowl.

I'll then be adding a high level Mercedes tank for the piece of mind of a constant head of water above the water pump.

BTW : Front fitted electric fans are usually fitted as a supplement toa viscous fan, so you'll need to replace yourdodgyviscous too. As a knackered one willbreak and cause severe damage to your radiator I don't believe that even the biggest electric fan will be sufficient on its own,even ifyou remove the viscous and rear mount the electric one.

As there are various temperature senders withdifferent effects on the Stag temp gauge reading I strongly recommend borrowing an infra-red thermometer to get an accurate reading of your temperature at it's own 'normal' needle position. Which if recall correctly should be in range 90 to 95 degrees (please correct me if this is wrong !), ifyour 'normal' seemsOK then make a good mental note of the needle position and only become alarmed at significant upwards deviations.


To summarise,asupplementary electric fan or cowl is down to personal preference as both have their advocates - my advice is to try to stabilise your cooling on the standard setup (otherwise you could be masking a problem) beforeconsidering the upgrade options. Howeverthe Mercedes cowl option is likely to becheap and easy to fit even as a trial, which might be a consideration having forked out for a new viscous first.

[tedlit]

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Paul M Goldsmith wrote:

As there are various temperature senders withdifferent effects on the Stag temp gauge reading I strongly recommend borrowing an infra-red thermometer to get an accurate reading of your temperature at it's own 'normal' needle position. Which if recall correctly should be in range 90 to 95 degrees (please correct me if this is wrong !), ifyour 'normal' seemsOK then make a good mental note of the needle position and only become alarmed at significant upwards deviations.

I was poking around my engine yesterday, and was contemplating the same question.. "what's a normal temperature if the cooling system's happy?"

I have an 88 degree thermostat fitted, and my head temps range from 89c ( front) to 96c (right at the back, where the heater hose exits). I don't know if that's *right* or not, but that's what mine is!

[SwissSteve]

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My Fan issue was a flown fuse! :?

[robertt1948]

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Hi,

Depends if the 20 A rating is AC or DC.If it is AC then the DC rating might only be 6A.

Have a look on the switch body for its full spec.

Robert

[robertt1948]

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Hi Floyd,

I agree with Paul. I've posted before that my new coupling is so stiff that I can only just flick the fan only one blade at a time. The improved draught of air from a new coupling is dramatic.

I believe that the mechanical fan can absorb at least 2 hp ( hence the reason for some people removing it). That is about 1500 watts. Divide by 12 volts gives 125 amps. I'm sure a kenlow doesn't take 125 amps so how can it possibly compare to the mechanical fan?

When you fit your new fan locate it at the top right of the radiator ( looking from the front of the car) to cool the hottestpart of the core.

Regards

Robert

[KOY 23]

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I bought a 12" Pacet profan, which I was assured by the supplier would be up to cooling a Stag without the help of the mechanical fan. I did not want too big a fan to restrict the airflow. It is mounted top right of rad. as suggested by Robert. I still use the mech fan, the electric is on a 97degree switch and will cut in after long idling after a fast run on a hot day and soon cut out again. Just what I wanted.
I also have the Merc header tank. Now I do not worry about overheating in traffic jams, or low water.

I have heard bad reports about using fan mounts that push through the core. The mounts can wear through the tubes.

John

[Stagdad]

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I Have a 16" kenlowe on a 97 stat as well as a good viscous fan and a header tank.The kenlowe never comes on which at least tells me my coolant is staying under 97 Deg .I also can switch it on via the Heated rear screen switch as i haven't got a hard top so use it for the kenlowe instead.

Steve

[SwissSteve]

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Curious how you wired into the fan. Did you use a relay or just wire across the Kelowe thermostat contacts?

[Stagdad]

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SwissSteve wrote:

Curious how you wired into the fan. Did you use a relay or just wire across the Kelowe thermostat contacts?

Steve

If it's me your asking ,i have a 30amp relay with 2 feeds to the low current side 1 from the thermostat and 1 from the heated rear screen switch.

Cheers Steve