I have done some searching on the topic but have not come to a very clear conclusion.

My 1982 S2 FB is running an OEM style rad and an OEM oil cooler.

I am looking at swapping in the aluminum Koyo rad for the purpose of: increased cooling capacity, durability, an electric fan swap (maybe) and future 13B installation.

My rad is also developing a small leak where the bottom tank meets some of the tubes. Which is also what had me thinking about the Koyorad. I can't find any decent quality Series 2 FB radiators available. I've heard the e-bay aluminum ones work but I am still skeptical! On my car I always try to use OEM quality hardware.

I have recently picked up a GSL-SE oil cooler and plan to use this as the starting point.

-From pictures of an -SE, it appears the cooler mounts to brackets on the frame rails, directly behind the chassis crossbar and in front of the sway bar. So need to fabricate brackets for this.
-New lines required, I like the Aeroquip line hardware I am currently running so would make up new ones. (Aeroquip Startlite)
-As the rad outlets sits lower, presume I need new lower rad hose and heater core supply hose.
-Re-use original fan shroud?

 

Looks like Champion has first gen radiators in stock. The thing toi be careful about is the size of the top low coolant threads. The ebay ones are wrong. Not sure about the Champion ones.

I bought an aluminum one for a 1979 project and it's working so far and was a great fit except for the mentioned top low coolant size.

https://shop.championcooling.com/Per...a-RX-7-SKU-701

 

My son called his car ZipTie when he first got it... as that's what we found was holding his cooler to his radiator as the brackets were both broken.

If you are still looking at online aluminum radiators, this one fitted my first gen (with oil cooler under radiator) perfectly using the original radiator shroud. Two issues with the accessories though. The first issue as Kansas reports is the coolant low sensor thread in the radiator does not match the oem coolant sensor. I tried drilling out the female hole on the top of the radiator and tapping it for a reducing adapter but screwed it up and ended up cementing the adapter and sensor permanently in place with high temperature epoxy. Second issue is the radiator cap is also a different size and had to try three or four mail order versions until I found one that had the correct depth. (If you go this way, let me know and I'll see if I can dig up what cap I ended up using). New radiator has maybe 6 months of regular and spirited driving on it with no problems, with temp gauge reading 1/3 of the way up its scale.
https://www.radiatorexpress.com/prod...221255/1192249

FOr the cooler.... On my FB the original oil cooler mounted to the original radiator itself, not to the frame rails. (Sounds like the SE is different?) On mine the original radiator had two female threaded holes each side to which the cooler brackets attached with bolts. The RadiatorExpress radiator has the same female holes in the correct place which is REALLY helpfull. To give you an idea of how the brackets looked, Mazdatrix has them. Its pretty easy to take the basic idea and build your own brackets to span between whichever cooler and radiator you end up using, but having the female holes on the radiator and cooler really helps. But then again, if your starting point is a cooler with a different mount pattern all this is irrelevant.
https://mazdatrix.com/product/mount-...unt-rx7-79-82/
I used the 8066 cooler, and fabricated a bracket from aluminum L angle that spanned between the two threaded female holes in the top of the cooler, and the four female holes in the radiator.
https://www.summitracing.com/parts/csf-8066
The cooler fits and works very well. Running the oil lines is a little tight as you exit the cooler as they exit at 45 degrees rather than straight back, but sounds like you are comfortable fabricating your own lines that would not be a problem, just use a 45 degree connection immediately as you exit the cooler so the lines are then pointing straight back parallel to the engine, and watch the angle at which you finally tighten down the fittings so the lines dont rub against the frame.

Anyhow, take all this with a massive grain of salt. I have done this exactly once and am very much a noob.

 

oil cooler lines need to get longer, you could just buy some hose and remake the lines, or buy the GSL-SE set
you'd need radiator hoses for an 83-85. the heater hose is the same i think
the shroud will bolt on i think. the 83-85 shroud is different

 

I'll be going through this as well some time soon with a Koyo radiator and CSF 8066 oil cooler.
j9fd3s is spot on from the old threads I've been going through.
The radiator bolts in and the 83-85 hoses radiator hoses are needed. The heater pipe to radiator hose is longer on 83+.
The bolt holes for the fan shroud are different on the taller radiator.

I think I can have the cooler sit on the front chassis tube with this u-bolt and drilling holes in a square tube.
It's in CAD because at first I was going to get fancy and have a bracket machined until the shade tree bug bit me.
It's going to be mounted higher than the oil outlet on the engine but I'll mount the thermostat higher up on the radiator support to prevent the cooler's oil draining back.

 

If you want, I can cut stuff on my 4x8 CNC Plasma table. Just send me a dfx file and pay a little return shipping of the parts. It would need to be cut from flat metal.

 

with mine i have the cooler horizontal behind that circular bar, and then i made a scoop (out of a cereal box!), and it seems to work great.
i did this primarily to get the oil cooler out of harms way when i have an off track excursion with the thing

oh yeah and then there is the Lemans setup.

 

Great info! Good advice too on the rad hoses, so need to get all of them new. I got all new hoses for the '82 setup from Mazda so I will do the same for the tall rad hoses.

I know there are some options out there for Aluminum replacements (for 1982) but so far the Koyo for the -SE is all I can find that is of the highest quality.

The u-bolt bracket idea is great. I was thinking of drilling holes for M6 Rivnuts into the chassis but the u-bolt saves the chassis from any modifications.

 

Bumping this thread to confirm that the 83-85 hoses are all that's needed to install a tall radiator into an older car.
This morning I installed the Koyo into my 1982.
I had to snip the ears on the radiator a little so it would sit on the radiator support tabs and get the bolt holes lined up. It was either that or cut off the tabs, but I preferred them there to ease installation.
U-bolts and steel angles mounted the CSF oil cooler up front and I made new AN hoses.

 

That looks nice. Good work.