Side Housing Outline; Side Housing Construction - Mazda RX-8 2004 Service Highlights

SIDE HOUSING OUTLINE

• With the adoption of a side intake and exhaust port system, the exhaust ports have been moved from the rotor
housing to the side housing.
• Intake and exhaust port overlap has been eliminated on the side intake and exhaust port system by way of
independently set intake and exhaust port size configurations. As a result, stable combustion is achieved due
to the combustion gas not flowing into the intake process.
• With 2 exhaust ports per rotor, the current exhaust ports have approximately 2 times the exhaust port surface
area compared with the previous ports. Because of this, open-timing on the exhaust ports can be retarded
while maintaining sufficient port size. Therefore, the expansion process period has been increased, improving
heat efficiency and resulting in high engine output with reduced fuel consumption.
• Intake air resistance has been largely reduced by the approximate 30% expansion of the intake port surface
area compared with the previous ports. By retarding the close-timing of the intake ports, intake air volume has
been increased for higher engine output.
• With the adoption of side exhaust ports, non-combusted gas, which used to be swept by the apex seals, is sent
to the next combustion process for re-combustion, resulting in reduced exhaust from non-combusted gas.
AUXILIARY PORT
(HIGH POWER ONLY)
INTAKE PORT
EXHAUST PORT
PERIPHERAL
EXHAUST
(RX-7)
EXHAUST PORT
EXHAUST PORT
PERIPHERAL
EXHAUST
(RX-7)
NON-COMBUSTED GAS
End Of Sie

SIDE HOUSING CONSTRUCTION

• To speed catalytic activation during cold-engine start, inserts have been installed in each exhaust port to
maintain the higher temperatures. Above each exhaust port is a secondary air port, which sends secondary air
close to the combustion chamber.
• The housing forms the engine outer core with the intermediate housing positioned between the two rotor
housings, which are further enclosed by front and rear housings. The components of the housing are
positioned precisely using tubular dowel pins.
MECHANICAL
PERIPHERAL
EXHAUST
(RX-7)
SIDE EXHAUST
(RX-8)
SIDE EXHAUST
(RX-8)
SIDE EXHAUST
(RX-8)
ROTOR
EXHAUST PORT INTAKE PORT
PERIPHERAL
OVERLAP
EXHAUST
B T B
D D
D
C C
C
SIDE EXHAUST
EXHAUST PORT
EXHAUST PORT
NON-COMBUSTED GAS
CHU011010908S03
01–10
SIDE EXHAUST
PERIPHERAL
EXHAUST
ROTOR
CHJ0110S004
CHU011010908S04
01–10–5