G35 Fan Direction?

[drgtr]

Hi Guys I installed the G35 fan and used the same direction of the original blade.

Now everyone has been telling me I have installed it backwards.
The G35 blades are opposite to factory?
Plus you have an "F" marker for front.

I totally ignored this because was trying to use common sense and follow the direction of the factory blade.

Sounds like I definately installed wrong which im fine with and will change but if the fan spins a certain way.

From an airflow point how does the blade being in the opposite direction create better airflow?

Dumb and curious I guess.

[Hodge]

Fucken hell... Now you're going to make me go and check mine. I definitely went with the "F" to the front route.

My temps went up 1-2C after fan fitting. But I put it down to the viscious hub, having more drag due to a larger fan, and not coping. I bought some toyo oil to put in, but never ended up doing so.

[drgtr]

Lol my car is cool around 72 degrees suburb cruising. Highway around 80 on a hot day. So even backwards fan it works..

This has me really confused

[MB]

Apologies gents, truly have no idea of these G35 fans under discussion.
An old proven trick for say blokes running elecy fans to check their polarity direction I believe is a sheet of A4 paper. Lowered between the donk and fan/s will prove a backward kite and or confetti machine :-(


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[NissanGQ4.2]

From an airflow point how does the blade being in the opposite direction create better airflow?

Dumb and curious I guess.

Nothing dumb about it,

I'm lead 2 believe pull fans are more efficient, even more so with a cowling, push fans are less efficient but will still work

[Hodge]

No ifs and buts here... Just checked and rechecked using the excruciatingly complex paper trick and my F is to the front , and it pulls air through the radiator and onto the motor...

However !! What would happen if you swap the fan around...
Fins will still face same way and push air same way , but would the shape of those fins be more beneficial or would it make it worse ?

It is a prick of a c*** of a job to take the fan off on mine and swap it to se results.

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[jff45]

The G35 fan leads with the elbow and not with the tip of the blade like a stock TD42/TB45 fan

[drgtr]

Some good answers here. Thanks guys appreciate them.
I just couldn't wrap my head around it.

[drgtr]

No ifs and buts here... Just checked and rechecked using the excruciatingly complex paper trick and my F is to the front , and it pulls air through the radiator and onto the motor...

However !! What would happen if you swap the fan around...
Fins will still face same way and push air same way , but would the shape of those fins be more beneficial or would it make it worse ?

It is a prick of a c*** of a job to take the fan off on mine and swap it to se results.

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Funny thing is when running backwards it stayed cool too

71 degrees cruising suburbs and around 83 degrees highway 110kmh


Changed it this morning.
F at the front

80 degrees highway 110kmh
72-73 degrees suburb cruising

though only difference today is 38 degrees c in Sydney where I am

[drgtr]

Nothing dumb about it,

I'm lead 2 believe pull fans are more efficient, even more so with a cowling, push fans are less efficient but will still work

Interesting . I might read up more. I have always thought blowing onto the radiator to push heat away like a fan on our body at home on a warm day

[drgtr]

Also is it worth installating a second condensor fan on the drivers side or would that just mess up air flow and make it worse?

[the evil twin]

2nd fan 'inline' will not usually improve many situations and can make it worse.

The principle in play is thermo-dynamics.
The objective is to draw thermal energy from the Rad and into the air mass and dump the air.
The air mass energy dissipation is directly related to the fan efficiency and rated in 'cubic feet a minute'.
The more cubes you move the more change in temp you get (delta T)
If you have one fan that has a higher CFM than another "inline" then the 2nd doesn't do much except impeded flow.
Exception is where one is a fixed CFM (elec) and the other is variable and both can free wheel.

Pushing or pulling is not relevant if the fan is ducted.
What goes in the front of the fan comes out the back so if the fan is ducted onto the Rad , front or back mount is irrelevant.

DOR of the fan
Some fans are universal IE the blade is symetrical and shifts the same CFM no matter the DOR
Many fans are not and the fan blade is asymetrical (aspect ratio changes towards trailing edge) and designed to be more efficient (much more usually) in one DOR.
If you want to reverse the operation of an asymetric fan you have to swap the position of the assy from behind to in front, swap the fan blades on the shaft, and swap the polarity of the motor.

The above is some of the reasons why the A/C condensor fans are offset and have their own 'duct' in relation the engine driven/Rad fan combo on a factory vehicle.
It is also some (not all) of the reasons why if you fit eleccy fans you rrsehole the engine driven fan

[drgtr]

2nd fan 'inline' will not usually improve many situations and can make it worse.

The principle in play is thermo-dynamics.
The objective is to draw thermal energy from the Rad and into the air mass and dump the air.
The air mass energy dissipation is directly related to the fan efficiency and rated in 'cubic feet a minute'.
The more cubes you move the more change in temp you get (delta T)
If you have one fan that has a higher CFM than another "inline" then the 2nd doesn't do much except impeded flow.
Exception is where one is a fixed CFM (elec) and the other is variable and both can free wheel.

Pushing or pulling is not relevant if the fan is ducted.
What goes in the front of the fan comes out the back so if the fan is ducted onto the Rad , front or back mount is irrelevant.

DOR of the fan
Some fans are universal IE the blade is symetrical and shifts the same CFM no matter the DOR
Many fans are not and the fan blade is asymetrical (aspect ratio changes towards trailing edge) and designed to be more efficient (much more usually) in one DOR.
If you want to reverse the operation of an asymetric fan you have to swap the fan, and the polarity of the motor (elec)

The above is some of the reasons why the A/C condensor fans are offset and have their own 'duct' in relation the engine driven/Rad fan combo on a factory vehicle.
It is also some (not all) of the reasons why if you fit eleccy fans you rrsehole the engine driven fan


Thankyou.

So in regards to push or pull. Its okay either way with the G35 fan? Originally I had it same blade direction as factory fan and it worked fine.
Now I have it the other way and it seems to work fine too.

[the evil twin]

Is it one of these? https://www.ebay.com/itm/Infiniti-G35-2003-2005-Engine-Fan-Blade-Cooler-VQ35DE-V6-3-5L-OEM-21060-AG202-/253002009317?fits=Model%3AG35
If so it is an asymetric fan and will be much more efficient with the correct DOR.
If you go by 'rude' measurement like engine temp, wet finger, sound etc it may well appear to 'work' either way.

If you measure the actual CFM with an anemometer I'll bet 1/2 a can of flat Suffolk it is shifting heaps more cubes one way compared to t'other.

If you are bolting it to the factory fan clutch the the DoR must be correct with the 'F' to the front or you are wasting efficiency

[drgtr]

Is it one of these? https://www.ebay.com/itm/Infiniti-G35-2003-2005-Engine-Fan-Blade-Cooler-VQ35DE-V6-3-5L-OEM-21060-AG202-/253002009317?fits=Model%3AG35
If so it is an asymetric fan and will be much more efficient with the correct DOR.
If you go by 'rude' measurement like engine temp, wet finger, sound etc it may well appear to 'work' either way.

If you measure the actual CFM with an anemometer I'll bet 1/2 a can of flat Suffolk it is shifting heaps more cubes one way compared to t'other.

If you are bolting it to the factory fan clutch the the DoR must be correct with the 'F' to the front or you are wasting efficiency


You Legend. Yes thats the one and yes thats the answer that I need to hear.

Thanks mate. You know your stuff!

[GUFLEX]

Digging up an old thread, But wondering does anyone know if a G35 fan will fit onto a ZD30DI viscous hub?

[mudski]

Digging up an old thread, But wondering does anyone know if a G35 fan will fit onto a ZD30DI viscous hub?

No and why would you want too? They don't overheat.

[GUFLEX]

No and why would you want too? They don't overheat.


Was just curious for the most part, as if i ever have to replace the fan in the future might as well upgrade (Have seen a few fans break apart from being perished/old)

[mudski]

Was just curious for the most part, as if i ever have to replace the fan in the future might as well upgrade (Have seen a few fans break apart from being perished/old)

Ahh ok. Even if it did fit you wouldn't see any benefit other than probably running too cold.

[BillsGU]

I don't think I have ever seen a fan blow back through the radiator to the front of the vehicle. One reason could be is that when you are driving along air is forced through the grill and then through the radiator. If you had a fan blowing in the other direction you would have opposing air flows.

[MB]

Of course Bill Mate[emoji106][emoji106]
The aim of our fan/cooling game is to ultimately pull backwards forward movement air through our hot water carry baskets up front. (Without GIANT 4 pack spotties hindering:-)
In regards electrical thermo fans they can and do hold their own somewhat limited cfm pushing/pulling weight at lower speeds albeit do hinder flow at faster highway speeds.
There is truth I believe specification read in electrical fans (if designed for polarity reversion) being more efficient in pulling than pushing due to their own cowlings creating a slightly greater efficient/amps vortexy situation :-)

EDIT: Electrical thermo fans in front of ones radiator (like your stock A/C fan) are ‘pushers’ Aftermarket competition type situations reverse polarity and drag through ones radiator I believe?
http://www.nissanpatrol.com.au/forums/images/imported/2020/07/186.jpg


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