How to mount radiator fans?

[cat007]

What's the best way to mount a pair of electric fans to the back of the radiator?

Do zip ties work?

[Bling]

Flat bar bent / drilled to suit would be a better long term solution.

[cat007]

Flat bar bent / drilled to suit would be a better long term solution.

Can you explain what you mean?

[crispy'86]

I'm picking what Mr Bzg means is getting some flat bar and drilling holes to suit bolting the bar to the radiator mounting points or where the shrod would normally have sat. Or an alternative suitable strong mounting point along the front

[ee904age]

You can get proper two-piece clips that go through the radiator between the fins.

[Adoom]

You can get proper two-piece clips that go through the radiator between the fins.

If the fins are vertical, the clips can end up tearing their way through the thinner bits between the fins.
I have a mate with these clips and quite a few times he has complained that they broke.

I recommend making some metal brackets from some suitable sturdy mounting point.

[sergei]

I would personally stay away from anything that physically touches the fins/tubes.
Just buy some ~25mmx~2.5mm alloy bar from your local hardware store and bend/drill up proper brackets, that bolt onto original fan mounts.

[MrOizo]

Like this



Problem with fixing the fans directly to the fins will be localosed cooling. With a shroud it will spread the low pressure area to the full area of the radiator.. Well thats my thinking anyways.

[DVSMOTORSPORT]

Yeh those cable tie things just suck, the fan can also move slightly and wear out the rad core if you dont use the foam isolators (or if they wear out).

Theres 2 ways I would do it. First way is to make up a small shroud that covers the whole rad that the fan can bolt to, only needs to be 2-3mm ali sheet, will work best if you can shape it so its not blocking part of the radiator e.g. how an origional shroud is shaped from a vehicle that origionally has a plastic fan. EDIT, as above has posted

Second is using 2 peices of steel strap, 25x3mm ish in size, that will bolt to the radiators side plates. The pics shown were the ones I made for my old commy, so would be slightly different to yours but same principle.

The 2 straps



Bent to the shape of the radiator with a bolt hole



Counter sunk bolt, counter sunk into the strap, welded and then ground back.

[Vertigo]

glad someone asked this, fabrication like this is an unknown to me

[tim_blair]

cable ties!

[Mr Revhead]

Long bolts and tap washers!

[Dell'Orto]

Weld/glue





Brackets are definitely the way to go though, those cable tie type mounts are horrible.

[Bling]

Flat bar bent / drilled to suit would be a better long term solution.

Can you explain what you mean?

Pretty much already been covered by pics etc. But just mean bend up some brackets to hold it secure like pictured. Cheap an easy. Engineering / sheetmetal places should have suitable stuff in scrap bins for cheap/free. Use factory or other existing bolt holes and make up brackets to suit.

[Rick]

Thats how I mounted my single fan, but looking back a shroud like MrOizo's is a very good idea.

[cat007]

MrOizo - how big is the gap between your shroud and the radiator?
I have some 2.5mm sheet ali that I could make something from.

Are you not worried that the parts of the shroud where the fan's aren't is effectively blocking the flow through the radiator?

[Dell'Orto]

No, they make the fans pull air through the entire core. Factory shrouds cover most of the radiator

[Snaps]

Are you not worried that the parts of the shroud where the fan's aren't is effectively blocking the flow through the radiator?

Look at all the factory cars that use fan shrouds and tell me which way you think is most likely better?

I'm in two minds about your comment actually - At first I'd think you're right when the car is at speed (blocking flow), and wrong if idling/stopped (as fan shroud would cause the WHOLE radiator to be used to cool, not just where the fan is). But at the same time, if you're at high speed with no shroud, the pressure caused by the fan would be spreading out towards the sides of the radiator, meaning a higher pressure behind the radiator sides (but not behind the fan), which would hinder flow through the sides?

Without some sort of fluid simulator I'd be hard pressed to prove this scientifically though The factory shrouds used should be proof enough anyway.

[RomanV]

Question for cat007, what type of car is this, and what radiator are you using?

Generally aftermarket radiators are designed for a certain type of car, and so have provisions for fitting the factory shroud and fan(s).

This is the best possible thing you can do.

If the car that the radiator is designed for came with a viscous fan, I would reccomend going to pickapart and finding a radiator fan and shroud with the same dimensions, and work on fixing that to the back of the radiator.

Fitting a bigger radiator, but then a crappy fan with no shroud could very well result in no net change to cooling ability, apart from more of a thermal flywheel effect if there is more coolant.

[loudstealthGT-Four]

This is the shroud I made out of 1.5mm. It has 10mm between the radiator and the back of the shroud.




I wouldn't go to thick with the aluminium as it will be difficult to bend, i managed to make mine out of one piece which was abit harder, but turned out quite tidy

EDITED: with bigger pics