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| 1969 System |
Three emission control systems are found on 1967 through 1969 Camaros:
* The Air Injector Reactor (AIR) system pumped air into the exhaust
manifold(s) to help complete the combustion process. The AIR system
consisted of the air injection pump (aka smog pump), a fuel mixture
control valve (1967) or an air diverter valve (1968-9), check valves,
air manifold assembly, and air injection tubes (one per cylinder).
* The Controlled Combustion System
(CCS) was introduced in 1968 and was used on cars that did not receive
the AIR system. CCS improved combustion efficiency via recalibrated
carburetor and distributor settings and higher operating temperatures
(compared to 1967). The higher operating temperatures were accomplished
by using a 195°F coolant thermostat (instead of 180°F) and the use of a
thermostatically controlled air cleaner (ThermAC). The ThermAC system
was designed to warm intake air to 100°F when underhood temperatures
were less than 100°F. It consisted of a damper door mounted on the
snorkel of the air cleaner which directed warm air from a heat stove on
the exhaust manifold into the air cleaner.
* The Positive Crankcase Ventilation
(PCV) system utilized manifold vacuum to draw crankcase vapors into the
engine to be burned. Filtered air was drawn through the engine, through
the PCV valve, and into the intake manifold.
General Application
In
1967 (as in 1966), emissions equipment was required only on cars sold
in California. The California cars were fitted with an AIR system
(Regular Production Option (RPO) K19), and the PCV system (RPO K24).
All engines equipped with K19 had unique engine codes due to the
required holes in the exhaust manifold(s). Also, the L26 (230 ci L6)
engines with K19 used a different distributor and the L30 (327 / 275hp)
engines with K19 had a different initial timing. Note that smog
equipment was not required on cars built in California but intended for
sale in other states.
In
1968 and 1969, the California and federal emissions requirements were
the same and all cars were built to the same 50-state standard. The AIR
system was installed on all L6 cars with manual transmissions, all
small blocks with manual transmissions, and all Camaros with big
blocks. (Chevelles and full-size cars with the 396/325hp engine and
TH400 transmission were the only 68-69 big block cars to not have smog
pumps.) Only the automatic L6 and automatic small block Camaros did not
have smog pumps, instead they had the simpler Controlled Combustion
System. Generally speaking, an automatic car required less aggressive
emission control than a manual transmission car because the engine load
(and carburetor fuel metering consistency) was more stable and
predictable.
In
1968, vehicles exported to Canada and other countries did not require
the AIR system. RPO KD1 was used to delete the system (if it would have
been so equipped otherwise) and 1/4"-18 NPSF straight pipe thread plugs
were installed in the manifolds. It is unknown if a credit was issued
on the Canadian window stickers for this delete. The Controlled
Combustion System was still installed on the exported L6 automatic and
small block automatic cars.
In 1969, Canadian cars used the same emission controls as U.S. cars.
PCV became standard on all Chevrolets in 1968 and is still used today on all cars.