so I have been searching on here for info on why Mazda changed their oil cooler design between 1982-1983 from a front mount to a top mounted oil cooler. Does anyone know what the pros and cons are to running each separate or can a person run both to help cool the oil more? I have both but I am trying to figure out the best setup on my 12a stock with a custom tubular header. Thanks for the info.

 

can't say i know why it was done, but i can say it was 1983-85 that they used the beehive.

i prefer the air cooler. it has more volume and will take you much farther power-wise.

for me, the beehive is simpler. also (in my particular experiences) they don't leak.

i don't have hard temperature data on either of them. that said, i have never had reason to suspect one was better based on stock gauge indications.

i'm sure you can create a way to run both if you wanted to, but i honestly don't see the point to it. on a stock or stock-ish 12A you can run either cooler without worry. i think the beehives were rated up to something like 180-ish and i don't doubt that some may have even run it at higher power levels.

 

Well I will strip the air oil cooler and save it then for now... I am currently looking for my shopping list to remove my rats nest.

 

i think i've seen reference in the Mazda literature to the beehive being less expensive, and it is simpler.

 

I dont know about you guys, but try rebuilding either one of them. The choice will become obvious haha.

 

Would there be much advantage to add the what you called the bee hive oil cooler when I already have a front mount oil cooler?

 

The fact ALL mazda rotaries used the FMOC (Front Mounted Oil Cooler - under the rad) up to the 1983
beehive "experiment" then went BACK to the FMOC style thru FC, FD and RX8s tells me everything about which system Mazda (and any other manufacturer trying to cool oil) thinks works best...

Stu Aull
80 GS (FMOC'd...)
Alaska

 

I guess my bigest concern is if I run both will my oil pump be good enough to push though them both or do I have to remove the beehive to run the under rad style?

 

itll be much more work than it would really ever be worth, esp as both coolers get oil from the same spot on the front cover, which would mean that you would have to make your own t-fitting for a parallel setup, or a full re-plumbing of everything for a series system. If you want to run 2 oil coolers, ide say just to run a pair of FMOC's

 

you're over-complicating your life right now. for stock or stock-ish HP you simply don't need that. make sure your cooling system is functioning well and the oil temperatures should be fine with either the air cooler OR the beehive. both are not NEEDED. if (or when) you need more oil cooling, you still DON'T WANT the beehive in the system.

 

Thanks that answers my question... I am going to change it over to the air cooled oil cooler uunder the rad.

 

Also remember that over cooling the oil can be just as bad as running to hot. I went with an aftermarket FMOC in my 1985 GSL but added an inline oil temp thermostat so the oil would come up to temp and not try to push heavy oil.

 

Just go FMOC, it's much simpler and performs much better than the "oil heater" behive style. Requires some parts and man hours but is worth it in the end.

 

racing beat used to have a nice article in the paper catalog, the gist being that the beehive is ok on the street up to the point where you're porting the engine, after that you need the front mount cooler.

on the street the beehive is nice, it warms up the oil more quickly, and keeps them there.

the big problem is that with the beehive the water cools the oil, so the radiator becomes more important, and if that isn't 100% everything runs hot, essentially you have all your eggs in one basket

 

Got it.

Thanks.

 

Only thing I will say about the FMOC, make sure you mount it correctly. My first FMOC on the widebody was overtightened and put too much stress on the bungs and cracked on the way to a show. That was embarrassing.

The other one just cracked three weeks ago due to weak rubber on the mounting bracket causing it to "wobble" and hit the crossbar in the front. Stress again. This time, I will be pushing the bottom of the radiator out with a very small spacer to move it away from that bar.