rotary engine, 6,000 rpm
Part 7: My 76 Mazda RX-5 Cosmo Restoration - Intake and Exhaust Porting
Has it been nearly a month since my last episode? Wow, time does indeed fly. I've been quite busy preparing to build the engine. So in part 7, I cover the intake and Exhaust porting. The engine is being built with GSL-SE 6 port plates and the Cosmo rotor housings as the basis for a 6 port turbo setup. This port job is fairly conservative, only opening up the primary ports a little and bringing the Exhaust ports close to 2nd gen RX-7 specs. The goal is to maintain fuel economy, low and midrange torque, and idle quality. This episode covers everything involved in porting including: marking out the new ports, grinding the port shape, smoothing the bowls, smoothing port to runner transitions, smoothing the runners, grinding and blending the Exhaust ports.