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Dave WM

Fan Clutch offset

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Never mind figure it out, I see there are two styles of fans, one for the 3 row crank pulley (zx power steering) vs the 2 row. I must have picked up a zx fan at a JY at some point, had it installed on my spare engine, and was using it for a comparison to my daily. The fan clutch is not an issue at all.

Edited by Dave WM
figured it out

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I recall using this to my advantage on my old car with Megajolt ignition. The larger offset ZX fan made room for the trigger wheel and sensor.

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I had to find the bigger offset fan for my Super Damper.....I found one with factory spacers.....gave me the clearance I needed. Curious if that came from a 280ZX with 3 row? Anyone seen these spacers?

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I am still a bit confused as a buddy sent me some pics with his setup and it seemed the Z fan (mount ring closer to the back or so it appeared) fit much better into the shroud.

I am going to pull the bottom shroud off, pull the fan, take the fan clutch off and do some measurement. My setup is stock, with a 3 row rad (after market copper brass), two groove crank pulley and the fan sits outside the back of the shroud about 1"

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that's 5.5 inches from the back of the core support at the top to the back of the shroud.

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with ZX  fan (I presume) mount ring offset towards rear of fan. I like this fit much better, still have about 1" clearance fan to rad

 

 

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hmm based on the slope of the shroud on the long sides, it looks like the air would feed in at the tip edge of the fan rather than in front of the fan. I may go back to the original. going to stop by a local auto parts place and confirm the dimensions of the AZ fan to a different make, just to see if  it was shallow.

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just seems odd Yarb that I needed to do this. check your distance from the front of the rad where it bolts to the core support back to the end of the shroud. Only thing I can think of is my rad maybe thinner than some others? The fan is actually completely inside now maybe 1/4 inch inboard of the shroud.

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Didn’t you recently change radiator? I thought about asking you if the radiator was thinner, but seems like you would have noticed that much difference between the two. 

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I had to find the bigger offset fan for my Super Damper.....I found one with factory spacers.....gave me the clearance I needed. Curious if that came from a 280ZX with 3 row? Anyone seen these spacers?


I’m really interested to hear about what you found as I’ve had to use spacers on my fan to clear the ATi’s stickie outie bolts (forgive me if I’m using complex technical terms here)!!

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Here is the fan I had to go with to clear the Super Damper....still barely cleared. Also, a picture of a set of fan spacers. I assume they are for the 280ZX’s to clear the three row dampers, but don’t have a clue if that’s correct. I guess you could easily make your own spacer out of a number of materials. Stickie outie is what I had too.....just glad it didn’t push the fan too close to the radiator....I didn’t want to go electric.Now that I look at it, I wonder if I could have symmetrically removed some of the inside corner of the fan blades to clear the stickie outie bolts?

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0CB67A50-567B-4032-AF91-0E79FD8B8782.jpeg

Edited by Diseazd
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well went to orileys and compared the fan they had, it was different in a lot of ways including thicker extending the fan about 3/8" further in. This one has cut out rather than holes on the mount that goes to the pully as well.

I opted back to the Z fan and this new clutch, seems to give a good compromise between the fan blades being shrouded and the angle of the shroud allowing air from the sides to enter in front of the fan. You could really see the issue looking under the car with the bottom shroud removed, get the fan too close and you could almost reverse the air flow on the sides of the rad.

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Here is the fan I had to go with to clear the Super Damper....still barely cleared. Also, a picture of a set of fan spacers. I assume they are for the 280ZX’s to clear the three row dampers, but don’t have a clue if that’s correct. I guess you could easily make your own spacer out of a number of materials. Stickie outie is what I had too.....just glad it didn’t push the fan too close to the radiator....I didn’t want to go electric.Now that I look at it, I wonder if I could have symmetrically removed some of the inside corner of the fan blades to clear the stickie outie bolts?
6C42B09F-F3DE-46FA-B180-880AB50A449F.thumb.jpeg.b244a0443cf58b377890a20383c3fd52.jpeg
0CB67A50-567B-4032-AF91-0E79FD8B8782.thumb.jpeg.f24cdcc8a535d35c9d127cfae5aec2b5.jpeg


Thanks for sharing! That is really interesting. I had to space mine out about 10mm. I plan to cut the end off an old water pump and use that to space out from behind - with a tiny bit of lathing of course.

Much like you I wanted to keep the mech fan. I will likely install a pusher fan at the front for backup on a hot day. Especially as the new (as of 3 years ago) rockauto fan clutch doesn’t seem to want to engage when the engine is hot. I can make it stiffen up with a quick flash of the blow torch but it won’t engage at high engine temps for some reason.

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@AK260 Have you thought about notching out a spot in each blade to clear those bolts. You could dremel out a notch in each blade to clear those stickie outie bolts. That would keep you from installing a spacer so thick that it would hit the radiator. Just a thought. I didn’t install those bolts in my damper. 

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[mention=32052]AK260[/mention] Have you thought about notching out a spot in each blade to clear those bolts. You could dremel out a notch in each blade to clear those stickie outie bolts. That would keep you from installing a spacer so thick that it would hit the radiator. Just a thought. I didn’t install those bolts in my damper. 


Well you know, I did indeed consider that possibility, however, I discounted it as I thought I would probably weaken the fan blades and / or not get it accurately enough and off balance it.

As it happens I still have some good safe clearance from the rad. But those bolts are indeed a pain! My engine builder kindly installed them as per instructions in the box. What bolts did you use?

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I just didn’t put them in. I assume they were for a degree wheel which I don’t use. Is that correct, or should they be installed? Stroker motor has been run hard for a year without them installed.

Edited by Diseazd

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I just didn’t put them in. I assume they were for a degree wheel which I don’t use. Is that correct, or should they be installed? Stroker motor has been run hard for a year without them installed.


Now what you say makes a LOT of sense!!! Especially so if you consider the picture below where the additional auxiliary pulley is bolted in using those same bolts. I am going to call to ATi at some point to confirm. I guess for good practice you still should put something in those holes to make sure they don’t accumulate water etc.

The only thing that comes to mind as I type is, I wonder if it would somehow off balance the damper if those bolts aren’t installed? I would absolutely love to get rid of them, they are a total nuisance!

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I spoke with Eiji....he said the factory recommends installing those bolts even without a crank fire wheel. I don’t know why, but above my pay grade to argue. FYI

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I spoke with Eiji....he said the factory recommends installing those bolts even without a crank fire wheel. I don’t know why, but above my pay grade to argue. FYI




That’s great to know, thank you for sharing. So we’re back on topic again then ;) and it’s going to be all about fan spacing!! LOL

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