Fan installed backward

[zd28er]

Hello, first post here.

I've had a zd28 mower, used, for about 4 years. Has always tended to run a little hot. Today I noticed that the fan appears to be cupped the wrong way. I think someone installed it backward when they rebuilt the engine. Has anyone else experienced this? I assume I'll need to remove the radiator to get to it.

 

[JasonW]

No experience with this mower but which direction does the fan rotate? If it is backwards you should be able to get to it by removing the fan shroud.

 

[chim]

What makes you believe it's backwards?

 

[zd28er]

Standing behind the mower looking forward, the fan rotates counter-clockwise. Seems the concavity is wrong. It should thinly bite into the air and then curve the air back towards the engine.

 

[Old Machinist]

If it rotates counterclockwise it is indeed mounted reversed.

 

[nbryan]

If the radiator fan pictured is supposed to pull air through the rad towards the engine then ya, the cupping of the fan blades should be facing the direction that air is being moved, not away from.

If flipped your fan will become way more efficient and move way more air.

I assume the fan as pictured from behind rotates counter-clockwise when engine running?

I would also look up the online parts catalogue as those diagrams are orientation-true.

Here's my B2650HSD fan for a reference:

 

[JasonW]

Yes looking closer at the blades it appears to be backwards.

 

[BBFarmer]

That is a sho nuff backwards mounted fan....... if i've ever seen one.

 

[zd28er]

Thank you all. Glad to know I'm not crazy.

 

[mendonsy]

The problem is ..... reversing the fan itself will not change the direction of the air flow. You would need to reverse the rotation or get a fan with the blades reversed.

 

[zd28er]

The problem is ..... reversing the fan itself will not change the direction of the air flow. You would need to reverse the rotation or get a fan with the blades reversed.

 

[zd28er]

I'm okay with the direction of the airflow...front to back, sucking air through the radiator. The problem is that, as/is, it is pushing the air mostly sideways and not pulling as much through as it could if reversed.

 

[zd28er]

Got it turned around, not a bad job but glad my hands aren't any larger . More air flowing over the engine now.

 

[NorthwoodsLife]

Nite and day... blades spinning the same direction... It's all about pitch.

 

[GeoHorn]

Be aware that SOME mowers are actually designed to BLOW air thru the radiator ..rather than Suck it… in order to reduce radiator-clogging from grass cuttings and such.

(Historically, some ag tractors do / did the same thing and the reverse-flow was purposeful.)

 

[WI_Hedgehog]

Sucking air makes the air less dense and cooler so transfers more heat from the radiator. Little did I know this before having to design a one-off cooler for an industrial project, but that's the way it works...or actually "doesn't work"...you know how compressing air in your air compressor heats it up--like it's hot--because work is being done on it? Drawing a vacuum does the opposite and cools it. Strange but true.

 

[lugbolt]

yes that's backwards

i bet the operator's station ran a little warm

 

[6869704x4]

Nite and day... blades spinning the same direction... It's all about pitch.

Those poor engines