Andy’s inspiration came from a guy called Mark Porter. The uppermost “run what ya brung” style race class in New Zealand is a series called GTRNZ, and during the 1990s Porter campaigned what is still to this day one of the wildest circuit rotaries to be raced in the country.
20B. Flame-spitting. Wide body. Fat tyres. Aural indulgence. That’s the Porter RX-7 in a nutshell, and it set Andy on a course for a 20B of his own.
The resulting engine package still powers the car today, albeit in a fine-tuned state thanks to a few years’ worth of development. With the Green Brothers handling the mechanical side of the equation, sitting low beneath the carbon hood of the FD is a dry-sumped, naturally aspirated 20B.
Inside the motor, Series 5 13B rotor housings wrap around a blueprinted, lightened and balanced rotating assembly. Naturally, peripheral porting is the chosen method of getting the 20B to breathe freely.
Internally, the engine is assembled with genuine Mazda parts throughout, an attribute credited with endowing the 20B with impressive reliability. Also ensuring reliability are Ianetti Ceramics apex seals. The ceramic seals are much harder than carbon variants, meaning increased lifespan and detonation resistance.
Words* & Photos: Richard Opie, Speedhunters
*Note: the words have been condensed and sometimes slightly edited for our site, use link above to view full article.