metal to plastic fan swap -question

[madkaw]

I am trying to swap out the original metal fan for a plastic one on my 71. I have several different clutches from cars that had plastic fans. My problem is that i am not clearing the third row pulley for the AC. The plastic fan needs to have another 1/4" clearance to clear the pulley. Seems that the height on all the clutches are the same -are they supposed to be? Or is the clutch for the plastic fan noticably taller or is there a spacer involved?

Any help would be great.

[Arne]

I just installed a plastic fan and clutch on my car a couple weeks ago, Steve. I only have a two row crank pulley though, so I'm not sure how much clearance I have down there.

My understanding is that the clutches for plastic fans were all the same until the ZX came out. The 260 and 280Z fans were apparently a bit larger diameter than the 240Z fans. But the one I used is a 260Z fan, and it still even clears my original fan guard on the top radiator tank.

I don't have my car with me here at work today, but can look at it later this evening.

[madkaw]

Well it took a lunch break to figure this out:stupid: The pulley wasn't sitting flush on the water pump so i lost what little clearnace I had because it was rotating **** eyed. Thanks for the info Arne.

Is there an easy way to tell if the old clutch is still good? Does it need to have just a little or a moderate amount of resistance when you turn it. I have two,but one seems to have a bit more resistance.

[geezer]

This thread discussed how to test the clutch.

http://www.classiczcars.com/forums/showthread.php?t=25817&highlight=fan+clutch+test

[madkaw]

Geezer,

thanks for the referall to that thread but it wasn't quite what i hoped for. It doesn't help me decide which one to install since there is no test cold. I thought maybe while the clutch is cold ,I could test it to see if it would turn with more resistance or turn easier or something like that kind of test before I install.

I guess I put one in a drive and see how it does. Maybe I'll check the service manual, maybe it will have some wisdom.

[sblake01]

It's kind of though to describe. It shouldn't turn easy as in free spinning. There should be some resistance but not so much that it's difficult to turn. The colder the amabient temperature, the more resistance but it should turn without having to grit your teeth.