Koyo Radiator Install 240z

[tehmbrick]

Picked up a Koyo aluminum radiator for my S30. Got down to installation and ran into a problem - the fan makes contact with the passenger side of the radiator (the cooling tank portion of the rad - see attached picture). After unleashing a few f-bombs, got down to trying to figure this out. Upon closer inspection it looks like the PO had installed a 8 fin fan from a 260z and it looks like the clearance between the fan and radiator are impacted by this (I hope - it appears the 260z fan extends forward further than the stock 240z fan). I've gone ahead and ordered a new fan in hopes that this solves my problem however, unless I'm missing something it looks like Koyo has made a poor design choice here .. why would they not design to have the fan fully behind the cooling fins vs. a portion over the side cooling tank.

 

Are there any S30 owners who have installed the Koyo and run into something similar? I'd like to rule out any other possibilities I'm missing. If the correct stock fan gives me some additional clearance it still looks like I'll have minimal room between the fan and radiator (<1/2").

 

Pictures attached. New fan arrives Tuesday so hopefully this works and I'll have time during the week to install.

 

PS. How do you get a profile pic up on this site? (does it really have to be a public picture from a website?

 

-TD

[tehmbrick]

Another note. Exactly 5.1 pound weight difference. Not 100% sure if the old radiator is stock .. thought the weight difference would be more.

[LeonV]

Looks like you may have a 280ZX fan on there. It has a different offset for the mounting face than the S30 fans in order to clear the extra pulley rows (WP/ALT, PS, AC). An S30 fan may just solve your problem. It can be 240Z-280Z, they're all the same in terms of offset.

 

Yes, your old radiator is OEM. The Koyo looks to have a larger core.

[Patcon]

Is it me or the fan on backwards? In the last picture the fan would rotate so the blade cuts into the air and pulls it in, right? So the curvature is normally on the inside like a boat propeller. Maybe the fan has more offset if you turn it over? Just guessing though...

[73str86]

Is it me or the fan on backwards? In the last picture the fan would rotate so the blade cuts into the air and pulls it in, right? So the curvature is normally on the inside like a boat propeller. Maybe the fan has more offset if you turn it over? Just guessing though...

 

After looking at my own car, and another spare fan, the fan is definitely backwards. And there is definitely an offset when you mount it. When mounted correctly to the clutch, the mounting surface is at the front of the fan. Flipping it will give you about a half an inch of extra room.

 

Did you have cooling problems beforehand? That fan is definitely not pushing as much air as possible to your engine.

 

Here is the spare fan for the offset reference, and photos of my clearance between a Champion 4 Row radiator, with an original fan, and new Nissan motor mounts on a '73 240z. It has more room at the top of the radiator. It is very close for my liking, with about 1/4" at the bottom. With 1300 miles I have not had a problem. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

EDIT: I just remembered my transmission is removed from the car. I have a scissor jack and a 2x4 bracing the engine from underneath so as not to snap the motor mounts. It may have shifted slightly when the transmission was dropped.

Edited April 26, 2015 by 73str86

[73str86]

Also look at the ~ 1 inch indents around the engine side of my two fans posted. 

 

Your ~ 1 inch recesses are on the radiator side.

Edited April 26, 2015 by 73str86

[Patcon]

^^^^^ Yes what he said...

[LeonV]

Good catch!

[tehmbrick]

Thanks gents. Based on your responses and a little more Google research I'm 100% confident I have the wrong fan (and that it's mounted backwards). It doesn't have any offset and as a result doesn't create the clearance necessary for the rad. New fan should be here Tuesday .. will post picture when complete and hopefully solved.

 

.. still a little suspicious about the radiator design but it may not really matter if I have the clearance. Unless the correct fan has shorter blades the coverage will still be beyond the radiator fins, which seems inefficient.

 

-TD 

[tehmbrick]

Offset on the fan was the issue. Installed correct OEM fan and I'm all good now.

 

Thanks for the help.

 

-TD

 

 

[Patcon]

Excellent. I would be curious in how you perceive the difference in cooling between old and new radiator

[Zed Head]

The fan clutch looks like the worrisome piece now.  Do you have the "stoppers" on your motor mounts?  Might save some damage in a hard stop or bumper bender.