1982 RX7 originally with 12a and the front mount oil cooler. This car sees some rough conditions on gravel roads and Rally X so I need to overbuild this system and make sure it can take away enough heat from the engine and be tough enough to take vibrations.

The oil cooler developed the typical cracks that they see in the neck. There are several cracks all around the fitting. Instead of trying to weld oily aluminum I am switching to an FC Front mount oil cooler as I understand they are better built.

The original radiator is what is called the "short" Radiator to make room for the oil cooler that sits underneath. 83 and up had a bigger radiator?

My thoughts is mount the oil cooler closer to the front of the car. Maybe in front of the radiator? The other thought is to get the "Tall" Radiator for more capacity but also making sure that the radiator reaches the lower pan (skid plate/wind tray/air diffuser?) so that air doesn't escape under the radiator failing to cool the radiator.
Thoughts?
Or will the short radiator work well enough?







So

 

There is a write somewhere in the first gen section on how to bolt a second gen oil cooler to the front round cross bar. It used some U bolts and angle iron. Of course, you have to make new lines up.

 

Whatever you do you have to seal up the gaps around whatever radiator you use. Otherwise the air flows around, not through the radiator and nothing will get cooled well.

On the stock SA system you have to have the gaps between the oil cooler and the radiator blocked and the gap between the lower engine bay pan and the cooler blocked as well. Otherwise your temps will never stay down in the 1/4 to 1/3 range on the guage. I have used black rubber pipe insulation foam (comes in 8 foot lengths and is split to slid over pipes). I take it and open it up and clue it to the borrom of the radiator withhi temp silicone. Then mount the oil coolers and do the same for the bottom of the oil cooler to the pan. Works like a charm and doesn't look noticeable.

As to making the oil cooler tougher for rally X, mount it rigidly (its on rubber stock) and also mount the engine as rigidly as possible to when it moves it doesn't stress the connections of the hoses to the cooler. Thats whats cracking the bungs.You could go so far as to isolate the hoses near the front strut with some heavy clamps to keep them stationary to the cooler to help with this as well. Just ideas off the top of my head.

 

Thank you T G Farrell

That was just the information I was looking for!

 

with mine i put the oil cooler horizontally behind the round bar. duct is very simple, its actually still cardboard. it works great, and since its behind the round tube, i can go off track and not worry.

i used the tall radiator, better idea might be an FC radiator, since its mounted at an angle, you might be able to get it in the car higher

 

What? NO NO NO! Absolutely not. The radiator and oil cooler should always be mounted with rubber isolating bushings. This is even more important in rally X where the vehicle is tossed around. The chassis flexes and moves which will put stress on the welds if the unit is not allowed to move independent of the chassis.

 

Ok, but the stock radiator is not mounted with rubber bushings. What stresses the welds is the engine and oil cooler moving independently and the hoses pulling on the bungs. Anything to lessen that is good.

 

The stock radiator is pretty well reinforced and made of steel and copper. Stock oil cooler, as well as a/c condenser are aluminum and always mounted with isolators.