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Discussion Starter #1
I've pulled out the radiator this evening to change the water pump, and it occurs to me that there is plenty of room to fit an electric fan in front of the radiator and do away with the crude plastic mechanical fan. I'm guessing a lot of you will have done this? Is Revotec the way to go? I haven't found any of the Alfa specialists that supply a specific kit. is it a worthwhile mod? On previous classics I've had with SU carbs I've experienced fuel vapourisation caused by under-bonnet heat which was a nuisance. Might removing the plastic fan cause vapourisation on an Alfa? Do they suffer from that? I'm on DHLA's.
 

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There's an argument for putting the electric fan in front of the radiator - looks neater, more room in the engine bay. Or putting it on the back of the raditaor - more natural air flow into the radiator, easier maintenance. Either is OK, you just need to make sure you get your suck or blow the right way round!

I put mine on the back of the rad, a 12" curved blade job powered by a Revotec controller in the top hose. Works well. I removed the original cowling, but you could probably retain it with the electric fan inside it.
 

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Why you want a electric fan. The car never ever runs hot with an original fan.
It's works PERFECT because it's SIMPLE.
Far more can go wrong with a electric fan ( why you think a S4 spider has 2 fans?)
You put more load on the already weak electric system of the car, thermo couples do fail often,
relais get burned in etc.
And when you put it in front of the radiator it's facing the weather (rain and dust) and also restricting the airflow.
 

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Fitted an adjustable pusher fan four years ago - works a treat
Just to counter some of the arguments
Mechanical fans can and do disintegrate taking your bonnet and rad with it...
You need the fan belt to be tight enough to make sure the fan doesn't slip putting more strain on the water pump bearings, electric fan no strain
Load on the electrics is minimal especially as it doesn't run all the time
No vaporisation despite running through some really hot days - I run DHLA's as well
Much cleaner looking engine bay
Easy to retrofit original fan (I keep the original fan in the boot just in case)
Much quicker warm up
Much quieter
Theoretically less power drain - although that's debatable
All moderns are fitted with electrics now, must be something in it

At the end of the day its up to you but I can recommend an electric fan based on personal experience - as you are in my locality I can show you my conversion (spider)
 

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My electric fan installation. I got the thermo switch from Alfaholics and mounted it in the bottom hose, which is the correct place, its the temp of the radiator that should determine the fan coming on and not the temp of the water coming out of the top of the engine. The fan was switched through a relay.
 

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I really can' t decide whether the controller should be in the top or bottom hose! :wobble: In reality I suspect it makes little difference. If it's a Revotec one, it's adjustable so you can have a play around with when you want it to come on. You don't want it "fighting" the thermostat.

Some instructions here:
https://www.revotec.com/acatalog/070032.pdf
 

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Discussion Starter #8
So, we've been distracted and posted some relevant info under 'what have you done today...' which you may not find so the wisdom is:- probably bottom hose for sender, using a 95 on 85 off unit, available on Amazon at a good price (about £25), but I'm also going to encorporate a manual override switch.
 

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So, we've been distracted and posted some relevant info under 'what have you done today...' which you may not find so the wisdom is:- probably bottom hose for sender, using a 95 on 85 off unit, available on Amazon at a good price (about £25), but I'm also going to encorporate a manual override switch.
I'll go with that, so the switch bypasses the thermo switch?
 

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I wired up a tell tale lamp so I could tell when the fan came on. If I went fast enough when the fan wasn't running, I could get the lamp to glow. :bigmouth:

Small things amuse small minds...
 

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Just my 2p worth,
Have had fan mounted in front of the rad for over 10 years on my Berlina.
Initially on a manual switch but since the body resto in 2014 when the rad was out I had a hole cut in the lower rad tank and a 22mm brass nut from a scrap rad soldered over the hole to screw an Alfetta rad fan switch into it.
Looks OE, in an Alfetta style.

Just an example of said switch (they are available with different switching temperatures)

https://www.ebay.co.uk/itm/New-Genuine-FACET-Radiator-Cooling-Fan-Temperature-Switch-7-5008-Top-Quality/192437629047?_trkparms=aid=222007&algo=SIM.MBE&ao=1&asc=20140122125356&meid=e722c5af566e4dc18df417a2e6c2a542&pid=100005&rk=2&rkt=12&sd=401525087931&itm=192437629047&_trksid=p2047675.c100005.m1851
 

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Ricksalfas, I take your point, having been told off, here is everything from 'the other thread':cheeky:

1: No No No! Fit it to the bottom hose! Think about it, thermostat opens, hot water fills rad, starts flowing down to the bottom whilst being cooled by airflow, cooled water returns through the bottom hose to circulate through the engine again. As the temp of the water increases the rad gets hotter, then once the water temp reaches X deg at the bottom hose the switch says 'the rads not cooling enough, time to switch the fan on'.

If the switch is in the top hose, the hot water never gets to efficient temp as the fan cuts in when the top hose is X deg not the bottom.

Take a look at your daily drive, it will have the fan switch (built into the rad) in the bottom.

PS I just done a Google on this and every bit of information I found says at the top, this makes no sense at all. Need to do a bit more research.

PPS, found this on Alfabb:

https://www.alfabb.com/bb/forums/spi...ls-needed.html

Take a look at page two. seems the jury is out on that forum! I'm going to ask around, maybe give this a rethink. Bottom hose might be correct, but then it might be the top!

2: What I did understand (from the Alfabb thread) is that whether top or bottom, the trigger temperature setting of the switch is key, lower for the bottom than the top. I need to check to see what mine triggers at.

3:Thats a great find Martin. I'd be inclined, to go for a lower temp if the switch is going in the bottom hose, I might just get a new, lower temp, although I see the AA add says splice into the bottom hose, that would suggest the switch is correct. Am I right in thinking you have a inferred temp gauge??? If you do, run the engine up to full temp and take a reading of the top and bottom tank.

This is interesting at the bottom of the Stoney Racing ad although they suggest fitting to the top hose:

" What Switch Temperature Do I Need?

This varies from vehicle to vehicle and colder is not necessarily better as the ideal operating temperature range for an engine may be higher than our "coldest" switches would allow it to reach.

A good rule of thumb is that the on temperature of the switch should be around 12°C to 18°C higher than the vehicles rated thermostat opening temperature i.e. the temp the thermostat begins to open at.

So for example if your thermostat starts opening at 74°C you want an "on" temp of 86°C to 92°C so you would use the 90°C on switch. If your thermostat opens at 82°C you want an "on" temp of 94°C to 100°C so you would use the 95°C on switch. "

4: Martin, this might be of interest from AlfaBB

https://www.alfabb.com/bb/forums/spi...gine-temp.html

I know others posted but I did provide several links which may be useful in the future.
 

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I’ve a revotec adjustable switch. Put in the bottom hose. Adjusted it to kick in at 85c...... which barely happens on a 1300 in the uk.

I also double checked the revotec temp was what it says it was with an infrared laser temp gauge. It was spot on.
 

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as an example, the s4 spider fan switch is about half way up the rad, nevertheless closer to bottom hose outlet.
not a great help I know, but that is where the alfa engineers placed it.
Thats a cross flow rad, so different again.
 

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Kenlowe fans always used to supply their thermostatic control with a copper capillary tube which terminated in a "bulb", which was inserted into the top radiator inlet.
They also supplied a thin shaped rubber which had a groove in it to accept the capillary tube. Then you formed a u-bend on the bulb end inserted the bulb into the top inlet, pressed the copper tube into the shaped rubber, fitted the top hose over it, and tightened up your hose clip.
Used them on many of my cars, worked a treat. This was always fitted in the top hose. I think they provide a different solution nowadays, but for around 50 years, that was the way they did it.
 

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Discussion Starter #17
I'll go with that, so the switch bypasses the thermo switch?
Yes it by-passes it so you can turn the fan on/off whenever you like, or leave it in 'automatic' mode. I don't like relying just on the auto switch and prefer to have the ability to turn the fan on manually if I wish.
 

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Kenlowe fans always used to supply their thermostatic control with a copper capillary tube which terminated in a "bulb", which was inserted into the top radiator inlet.
They also supplied a thin shaped rubber which had a groove in it to accept the capillary tube. Then you formed a u-bend on the bulb end inserted the bulb into the top inlet, pressed the copper tube into the shaped rubber, fitted the top hose over it, and tightened up your hose clip.
Used them on many of my cars, worked a treat. This was always fitted in the top hose. I think they provide a different solution nowadays, but for around 50 years, that was the way they did it.
My cheap ebay kit has a capillary bulb but i could never get the top hose to seal properly so took it out and glued it to the rad, works fine but its a bit untidy so I've ordered the one off Amazon and will fit it soon
 

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My cheap ebay kit has a capillary bulb but i could never get the top hose to seal properly so took it out and glued it to the rad, works fine but its a bit untidy so I've ordered the one off Amazon and will fit it soon
That's what was good about the Kenlowe KIt, the piece of shaped rubber with a groove in it to accept the capillary tube meant you never got a leak, as the hose went on easy, and the hoseclip tightened everything down evenly.
 
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