Oil cooler fix or new one for a FB?
 

I have an 1982 that the threaded cooler fittings are cracked and leaking. Years ago people whose sending them out to be welded up and I'm wondering who still dues this work? Is there any good after market options or is factory Mazda still the best option? I see Rotary works sells a cooler for $200 it doesn't seem bad if it's a good cooler.

I have the Rotary Works one. It's nice but does not have an internal thermostat. You can get similar ones cheaper or buy a good used factory one.

If it where me, I'd have the old one removed and -10AN aluminum fittings installed. You will need to buy/make a set of hoses if you go this route.

If you buy an aftermarket cooler, know if it comes with an internal thermostat. The thermostat is used to bypass the cooler to help get the oil up to temp. You can get external thermostats but they are not cheap. I have an Earl's one that cost about $100.

You could get one like this and use your existing hoses. Doubt it has a thermostat though.

http://www.ebay.com/itm/ALUMINUM-OIL...9XfxlP&vxp=mtr

Might try an AIRCRAFT repair facility? They work with aluminum components all the time, and considering what is at stake, you can be sure they prob know what they are doing. I had my SA FMOC sonic cleaned by an aircraft service co yrs ago...

Stu Aull
80GS
Alaska

If anyone is looking this place might be a good place to check out.

Pacific Oil Cooler Service, Inc.
1677 Curtiss Court, La Verne, CA 91750
Call Us Today, Toll-Free: 1-800-866-733

Automotive and Non-Aviation Oil Cooler Services


Aerokool.com
1495 S.E. 10th Avenue
Hialeah, FL 33010-5984
Phone: 305.887.6912 | 800.458.4255

THAT is where my FMOC was cleaned....thx for the reminder, and the Lead.
;)

Stu Aull
80GS
Alaska

I have the same problem. I found a new cooler for 130 shipped (oem) and have racing beat lines, I plan to install all this weekend.

Since I cracked the bungs on the last cooler, should I try installing the lines on the cooler first, mount it, then attached them to the housings after? This way I can hand tighten them outside of the vehicle and not risk cracking the new cooler? Seems like the racing beat lines are a bit shorter which makes it harder to tighten them when standing over the damn car lol.

any insight?

Don't do this from above, put it on stands and remove the pan and do it from below. Much
easier and less of a chance of bunging up your bungs.

I assume you mean oil pan(?) lol. Sounds good, Ill def try it from below and make sure to have the correct wrenches, which might have also been my problem.

Thanks for the info !

He's talking about the under tray used for better air flow.

Yeah, what he said, not the oil pan.

Gotcha...

Guess ill figure it out when its on stands

How would you rate their pricing?


Here is another repair option:
American Cooler Services
919 W Mayfield Rd, Arlington, TX 76015
Toll Free: 1.800.377.8808
Local: 1.817.419.8008

Have you considered upgrading to the Beehive oil cooler used in the 83-85 12As?

They're much simpler (less plumbing), more efficient and they never break.

No not interested from what I've read they are not good if they where any good I would think Mazda Trix would sell them.

Yes there are a lot of people on the FMOC band wagon, but on the other hand there are far more people using beehive oil coolers that you never hear about because they never have any problem with them.

After clearing away the urban myths, there are two potential issues or "limitations" to the beehive that you should take into account.

1) if you have a highly modified engine that generates excessive amounts of heat, the beehive oil cooler (which is designed and perfectly balanced to the stock 12A and a properly functioning stock water coolant system) may not provide sufficient cooling (but then, some FMOC's may not do the job either).

2) they are prone to leakage from the O rings that seal the unit to the oil system, causing the area below the beehive to get covered in engine oil. But looked at properly, this is simply a maintenance issue: Every 100,000 miles or so the O rings need to be replaced, about a 1 hour job. The O rings cost pennies, unlike the hoses and seals to the FMOC, which I understand are quite expensive.

It's true, Mazdatrix doesn't sell beehive oil coolers, but I think that's because new ones are too expensive. Atkins Rotary has new ones on ebay, but at $700 a pop they are way out there in purist territory:

83-85 12A Rx7 Oil Cooler (N231-14-700C))

The good news is that a used beehive, plus the hard line that connects it to the engine, are generally free for the asking. I have a bunch of both out in my shed.

So if you have a stock 12A, even an earlier model with the FMOC, the beehive is a very inexpensive option, especially compared to replacing the FMOC, new or used.

And as I've already mentioned, other than the O rings, which are a minor maintenance item, they don't break.

ray green I will keep that in mind.

See post #17:

https://www.rx7club.com/1st-generati...ttings-969525/

Ray loves his beehives. Just know the beehive can only cool the oil down to the temperature of the
coolant coming through it from the back of the engine after its been heated up by the block. The FMOC
can get the oil much cooler than that and we know most of the cooling of a rotary happens through the
oil, not the coolant.

1/3rd = most?

Go to the junk yard and get an FC oil cooler. Your welcome. :icon_tup:

I have a second gen cooler, mounts, and the hoses adapted from a second gen to fit a first gen. PM if interested and we can talk price.

This cooler is made to mount on the round cross bar in the front of the car.

I always heard it was over 1/2 the cooling was the oil circulation because its the only thing
cooling the interior of the rotors via the eshaft oiler holes. Still the FMOC will work better and
at a larger temp range than the beehive.

When My SA oil cooler fittings cracked and started leaking due to age, corrosion, and over-tightening to try to stop the leak, I took the cooler out, and made a reinforcing ring out of a washer. I die-grinded it to a slight interference fit. Then I cleaned that area with carb cleaner, used a plastic hammer to install the ring, and covered it with loctite 2 part gas tank repair.
https://cimg4.ibsrv.net/gimg/www.rx7...a211df2514.jpg

Then I used a flat stone to get a good sealing surface, and I used a self centering Dowty washer instead of the mazda washer. They are available at hydraulic supply stores, I brought my fitting with me to show the guy at the counter.
https://cimg0.ibsrv.net/gimg/www.rx7...1e4c8d6d4a.jpg

You can see in the picture how it keeps the washer centered on the fitting. I am using the Racing Beat oil lines.
I also used a little bit of oil pan sealant as insurance.
It has been over a year, and no leaks. It cost less than $20.
I didn't want to try to weld it, as old aluminum is tough to weld.

brilliant! thanks for posting!

Stu Aull
80GS
Alaska