Racing Beat's Peripheral Port Housings - 1974-1985 Racing Beat 13B Turbo - We offer five different types of Peripheral Intake Port Rotor Housings: four 13B models and one 12A model. The 12A model and one of the 13B models are Mazda Factory Race (MFR) housings. Because the MFR housing is relatively expensive we developed our own 13B Peripheral Port Intake Housing - equal in performance to the MFR housing, but at a substantially lower price. Our Racing Beat-modified housing has not been approved by some sanctioning bodies, such as SCCA, while both MFR housings have been approved.
Both the 12A and 13B MFR housings are designed to mount a MFR Peripheral Intake Manifold. A special Mazda O-ring is required to seal the manifold to this housing. Note that the 12A and 13B MFR housings have an exhaust stud pattern that is much different from stock. We offer special headers to fit these housings, as well as the separate flanges.
The Racing Beat-modified 13B housing begins as a stock housing, but we bore and tap the housing, screw in and epoxy a threaded O-ringed tube, port the intake, and then race port the exhaust. The connection from the intake manifold to the housing is made with heavy duty hose and hose clamps (supplied with the Racing Beat peripheral intake manifolds).
While the Water Jacket Modification is not included with any of these housings, it is highly recommended. (See Engine-Services)
Note: When using peripheral intake rotor housings, be sure to either select a rear housing in which the intake area tension bolt position is unmachined (most 1976 and later housings) or plug the hole. If left open, the hole can seep water out of the engine.