12a Rebuild: Suggestions for radiator replacement (?)
 

Yes indeed it is running but needs some tweaks.

Radiator is leaking, slow, but leaking. When I took the shroud off for cleaning, the right side of the frame fell off. I suspected it was leaking before, but the original foam rubber, now gone, concealed the drips.

Mazdatrix has an 83-85 all aluminum for $187.
https://www.mazdatrix.com/b8.htm

Atkins has an 83-85 for $275.
83-85 12A & 13B Rx7 Manual Radiator (N304-15-310)

Black Dragon 83-85 for $220 (including the extra handling charge)
Datsun 240Z, 260Z, 280Z, 280ZX & Mazda RX7 iCatalog - Black Dragon Auto

That's a big price spread.

Opinions/suggestion, previous experiences, would be most welcomed.

(double-posted in prior thread. it was late. Please reply here.)

If you prefer the aluminum one a friend of mine (username msimonov) recently bought the mazdatrix version and was very pleased, found that it was an exact replacement and had no complaints.

I concur on the aluminum radiator from mtrix, I've seen Mike's installation and it's very pretty, just like stock only in AL.

I bought a universal one from AutoZone last time, and it was almost an exact fit. One threaded hole for the FMOC was mispositioned by a few millimeters, requiring a little judicious dremel work, but otherwise fit well and has performed fine.

Wonderful.
It turned not to be a few drips. This am I noticed a puddle from last night's running.

Just DO NOT do what I did and buy a GM/universal unit. It took me over a month to figure out my radiator hose situation.

RockAuto, with shipping its cheaper than any b&m autoparts store out there and it works fine.

I got my mazdatrix one a month ago and it's perfect. Just remember to buy a cap as well. I almost made the assumption it would come with it

Anyone have any feedback on the CSF rad that they sell for the FB?

CSF #699.

Core Size 11-7/16 x 21-5/8 x 2-1/16
Tank Size Inlet 21-7/16 x 2-3/16
Outlet 21-7/16 x 2-3/16
Hose Fittings Top 1-1/2 Right
Bottom 1-1/2 Right
No of Rows 3
Oil Cooler 7-7/8 in.
Tech. Note ALL METAL model.


I was hoping it is a good option as this is something that could be obtained locally.

I ordered the Mazdatrix 83-85 yesterday. It is scheduled to arrive on my doorstep next Thursday.

I did replace the cap with a new one last year, but not one specified for my 84. So I ordered the correct one along with the radiator.

In the meantime, I have the time to finish the front brakes, replace the melted exhaust hanger, clean up the underside, and make as many adjustments as I can without running the engine.

We're having same starting of a slow leak on our Radiator in our 84'. When it arrives please post a pics so I can see what it looks like that thanks.

Absolutely.
Out of the box and installed.

The Mazadtrix radiator did not drop right in.
Well nothing on mine just drops in so this was to be expected.

Seen in the second image it has more surface area. The bolt holes line up without issue but there was some cutting and filing necessary on the side flanges: top and bottom right and below the top left bolt.

The bottom has connections for auto trans, but I just tighten down the connectors and looped a vacuum line over the pipe ends.

The OEM top bolt for the fan shroud is too short, so Lowes was the answer.
The OEM snap-in plugs for the bottom holes for the fan shroud were too small. So I used some Ford ones I had laying around.

A little more work than expected, but all little stuff.

I would have assumed a rotary shop selling a specific FB rad would at least mention that mods may be necessary.

None the less, install looks good!

Bumping this thread, still looking for feedback on the CSF rad...

I'd like to go with it since it is something I can get locally and CSF is a good brand.

Any body know?

I think it includes inlet and outlet for an Auto tranny cooler but those would just get capped...

CSF #699.

Core Size 11-7/16 x 21-5/8 x 2-1/16
Tank Size Inlet 21-7/16 x 2-3/16
Outlet 21-7/16 x 2-3/16
Hose Fittings Top 1-1/2 Right
Bottom 1-1/2 Right
No of Rows 3
Oil Cooler 7-7/8 in.
Tech. Note ALL METAL model.


Reason I ask is I know have every single piece needed to overhaul my cooling system..

All new OEM hoses.
OEM T-stat
All gaskets etc.

Now I just need a rad....

Edit.. I think I answered my own question.

Mazdatrix lists the 79-82 rad as "699RAD" which leads my to believe it is the CSF unit.

Good enough for Mazdatrix good enough for me.

A leaking radiator + faulty temp sender eventually did my 12a in.
Yes, I installed all new hoses (rad, heater, oil cooler), clamps T-sat and gaskets.
Now no leaks and a reliable reading on the dash gauge.

Bumping this thread rather than starting a new one. I've got a 1980 with the 12a and my radiator just sprung a big leak yesterday.

Is there a difference between the 79-82 and the 83-85 radiators? I was looking at the Koyorad aluminum radiator here https://www.eliterotaryshop.com/radi...-hh063144.html but I can't get confirmation that it will fit my car.

Any help would be greatly appreciated!

The 80 needs the short radiator because of the oil cooler. The 83-85 are taller for the 12A by 4 inches.