Rotary Engine Shop in Colorado | We have customers that still run the 12A engine in their vintage race cars.
Why? Because these smaller motors are tough.
Do the right maintenance, use the proper process when building them, with solid cooling systems, these motors will last for years.
One of our builds from 2017 came in for some TLC. Here we have a 12A motor with a street port, weber carb, header, upgraded oiling system and larger radiator / electric cooling fan.
Here is a pic of that motor when it was built in the winter of 2017, lapped housings, FD stationary gears, polished rotor housings, etc.

Why is this preferable? Because these motors were not beat on as hard as a MT car would have been back in the 70/80's.
We mixed and matched the best components to build a solid motor.
After 6 years of racing in the Rocky Mountain Vintage racing club here in Colorado, we did a compression test and recommended that the motor come out and be freshened up.
Good thing too. The first thing that we look at is how it comes apart, fortunately it came apart as it should have with normal wear on bearings. Everything looked good with the exception of the apex seals, closer examination showed us that taking it apart was very good in terms of preserving the life of the rotor housings.
The rotor housings were showing early signs of wear on their outer edges. This is due to the apex seals bending. Because I have been involved with this car / motor from the beginning, once we got the camera mounted in the car for analysis (several years ago), I was shown that the car would sputter on the top end pulling down the long straights. Getting a camera saved this motor from self destruction. I can't emphasize enough how important this is, drivers feedback isn't as reliable as looking at real data.

Please note: Using a camera like our Cambox visor cam is a critical piece of hardware for us builders, especially when cars like this do not have data logging ECU's. Details matter.
What else did we find?

The motor is back together with new seals, springs, etc. and ready to be dropped back in the car.
These motors like fuel, they like being in their happy temperature zone (water 185-195, oil 195-205F) in order to make meaningful power. Build them right and they will last.
Topics: 12A, Colorado Rotary Engine shop, vintage racing 12A