Engine cooling fan

[Steve123]

Question on the engine cooling fan. I have recently rebuilt my engine, got it put in last night. Putting everything back on it and wanted to change out the fan. The original had a fan with the fan clutch. I have read up on fan clutches and their purpose, wanted some recommendations to get a new fan clutch or run without one?

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Original fan clutch needs to be replaced. Thank you

 

[Craig 85]

Back in the early 90's I had to replace the clutch fan on my truck, but due to the fact I was young and dumb & was too cheap to buy a new clutch fan, I installed a flex fan. Big mistake. It made a lot of noise and took away power.

I would just replace the clutch with a good quality one.

Here's a link on Rockauto that explains the different types of fan clutches.
http://www.rockauto.com/genImages/93/haydenSD-HD-SVRD.pdf

 

[Dutch Rutter]

I would also replace the clutch fan with another. Summit sells quite a few different ones and they are not too expensive. Plus you free up some performance and MPG at least that is what they say. Normally, I've found I can "feel" more power and therefore drive it a bit harder which cancels out the MPG savings.

On a side note, I have read that when changing out a clutch fan you also want to replace the water pump and visa versa. Something about bearings causing vibrations which will wear on the newer part be it the pump or the fan clutch.

 

[Steve123]

Thank you for the advice. I am going to reinstall the fan clutch.

 

[Blue Ox]

I realize I'm late to this, but if you wanted proof:

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[Snoots]

Replace the clutch and get a 7-blade fan.

 

[Dutch Rutter]

I realize I'm late to this, but if you wanted proof:

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Pretty much the same idea behind under drive pulleys, removing your belt from the AC compressor and completely going to electric fans. It doesn't create power but it puts less load on the motor which in turn frees up available power.

 

[chengny]

Nobody asked, but here is a good illustrated description of how a fan clutch operates. It was a mystery to me for a long time:

A view of the internals:

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Engine (coolant and air from radiator) cold - the clutch is disengaged:

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As the engine warms up (and the temperature of the air from the radiator begins to rise) the clutch modulates the degree of engagement:

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With the engine at normal operating temperature - the clutch remains fully engaged:

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During periods of low load - when coolant (and air from the radiator) temperature drops, the clutch disengages:

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[Snoots]

Now it's only a mystery to those who don't subscribe to GMSquareBody.

 

[ScottyB]

I don't know about the bearing wear patterns, but for the cost of a water pump why wouldn't you replace it while you were there?

 

[trukman1]

When I did my last build I looked at the price of electric fans and decided to replace the fan clutch. If your not racing you have to ask is it worth the extra bucks. I vote for a new fan clutch and be done with it. Of course, on a new build I started with a new water pump so can't speak to that issue. Just $.02 cents worth.

 

[Dutch Rutter]

I don't know about the bearing wear patterns, but for the cost of a water pump why wouldn't you replace it while you were there?

This is my thought process with it. But its the same thing why oil pumps don't get replaced when someone replaces their oil pan gasket.

When I did my last build I looked at the price of electric fans and decided to replace the fan clutch. If your not racing you have to ask is it worth the extra bucks. I vote for a new fan clutch and be done with it. Of course, on a new build I started with a new water pump so can't speak to that issue. Just $.02 cents worth.

This what I read which talks about it. second paragraph http://www.haydenauto.com/fan clutch tutorial-part 1/content.aspx