I am new to the 12A motor in my soon be be delivered 1982 RX-7 and I seem to hear/read somewhere that there is a secondary tank for oil that the car uses to inject into the rotors.. Is this true and where is it and what kind of oil do I fill it up with...

Hope I dont sound stupid...

What else should I know that I didn't need to know with a 13B that I previously had...

 

There is no secondary tank. Mazda rotaries are equipped with a device calling a metering oil pump, a small pump that siphons a bit of oil from the main oil system and injects it into the intake to help lubricate the apex seals.

While it rarely fails, many owners like to supplement the MOP with the manual addition of a 2-stroke gas-oil mixture to the fuel tank during fillup. This is calling running premix. Whether or not you want this additional bit of insurance is up to you.

 

Your 13b had one too. Unless you decide to premix it will be the same as your last. 99% of the OMPs won't fail (pulled # out of my ***), but there is absolutely no way of knowing if the pump is running. Some people add oil to the gas which achieves the same result as the OMP, but doesn't rely on old hardware to keep your engine alive.

 

If you look down into the carb you can see the oil coming from the omp lines, so you can tell if it's working that way.Much more difficult on the FI engines though...

As for a separate tank for oil, like the others said, there isn't one from the factory. Some of us do get/make adapters to use a external tank though which is probably where you saw/heard that from

 

There's also a test in the FSM for determining if the OMP is providing adequate output, measuring output at specific RPM over time. It's a little tedious but not hard to do. The amount of oil delivered to the carb is very small, measured in partial CC's over several minutes.

It's not a steady flow; it is delivered in pulses every couple seconds, first to the front bowl, then the rear bowl, and it is throttled by a linkage to the carburetor.