Rotary Engine builds | Here we are putting together a 12A street port motor for a vintage Rx7 club race car.
When you belong to the Rocky Mountain Vintage Race car club, having the right car to play with on those event weekends is important.
The upgraded engine replaces their old tired race motor. Like the last post on race engines, every engine destined for racing is only going to have a finite number of laps in it.
Here we chose to have the side housings lapped and ported to street port on the intake and race port on the exhaust.
What does that get you? Well increasing the port timing opening and close for intake creates greater flow of fuel and air. With that comes power and moves the power curve up the rpm range.
On the exhaust side, we’ve opened up the port dramatically vs. stock. This allows the spent gases to escape and create a pulse wave like no other. This is where the ‘Brap, Brap’ comes from. It is also where the exhaust easily belches out flames, pretty cool when racing hard.
In order to handle the added power gains, we have used hardened stationary gears and all new seals at higher tolerances than OEM. This means that the time to set up the rotors is 2 hours each as all seals must be measured and matched to their respective grooves.
We also use an upgraded oil system with ported oil galleys, new parts and a high pressure regulator. The goal for this motor is reliability and make solid power. Add in that in vintage racing, they use carburetors. This build is not exception, we are using a weber 48IDA with a racing beat intake manifold.
We still have work to do on this build, add in an aluminum flywheel and racing beat low inertia high force clutch for good bite out of the corners. Then it is off to be installed in the car and tuned on our Mustang dyno.
Horsepower comes in many ways, for some it is the wail of the screaming angry Wankel. Stay tuned.