Racing Beat’s Peripheral Port Rotor Housings are available for the 1974-85 13B (Four Port and Six Port) rotating assemblies and for all 1987-95 Turbo (Four Port) and 1986-92 Non Turbo (Six Port) rotating assemblies. The 1974-85-application Peripheral Port Rotor Housings are based on the 1984-85 GSL-SE rotor housings. The Peripheral Port Rotor Housings for the 1986-95 rotating assemblies are based on the 1987-91 MAZDA Factory OEM TURBO II Rotor Housings, inasmuch as these are delivered from the factory without the exhaust gas “splitter” feature found on the Non Turbo version.
The race-proven production features pioneered by Racing Beat, utilized in the manufacturing of the Racing Beat Peripheral Port Rotor Housings, include: both boring and thread-tapping the rotor housing in advance of spinning the machined intake sleeve into place; incorporating an O-Ring to eliminate coolant leakage at the mating point between the threaded sleeve and the rotor housing; and using a high shear strength epoxy to both lock the intake sleeve securely and provide additional coolant sealing. The final manufacturing step, the machining of the intake and exhaust port timing, is performed entirely by hand, utilizing proprietary porting templates that have proven over the last 40 years to optimize horsepower output in both Turbo and Non Turbo applications.
We offer separately the “Water Jacket Modification” feature (Part Number 11488) on all Racing Beat-manufactured Peripheral Port Rotor Housings; This feature improves cooling in the “hot zone” of the rotor housing to improve both the life of the rotor housings and of the seals.
NOTE: When assembling an engine utilizing Racing Beat Peripheral Port Rotor Housings you must either select a rear side housing, as delivered by MAZDA, that does not have a machined tension bolt hole in the area adjacent to the Peripheral Port Rotor Housing intake sleeve (typically, not an issue with 1976 and later rear side housings) or you will need to plug this hole, if present, to prevent coolant leakage.
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