Pcv System; Piston Engines; Rotary Engines; Diesel Engine - Mazda 1983 RX7 Service Manual

ARTICLE BEGINNING
1983 Crankcase Ventilation
MAZDA
B2000, B2200, GLC, 626, RX7
DESCRIPTION & OPERATION

PISTON ENGINES

The PCV system includes 2 hoses and a PCV valve. Air
normally flows out of the valve cover hose, through the PCV valve and
into combustion chambers. A hose from the air cleaner to the valve
cover supplies fresh air to the crankcase.
When intake manifold vacuum drops due to heavy loads, the
amount of blow-by exceeds the capacity of the PCV valve. Air then
flows directly from the valve cover into the air cleaner and
carburetor. When engine is not running, the PCV valve is closed and
vapors are stored in the crankcase.

ROTARY ENGINES

The system used on the rotary engine (RX7) is also a closed
system and operates basically the same way as the piston engine
arrangement.
Filtered air is drawn into the system through the air
cleaner, mixed with the gases and vapors that blow by the rotor
during engine operation, and is drawn out through a purge valve and
into the intake manifold. The purge valve operates as the PCV valve
in this system.

DIESEL ENGINE

The PCV system on diesel engines consists of a hose to the
air intake from the cylinder head cover. All blow-by gases are
introduced into the air intake and prevented from entering the
atmosphere. There is no testing the PCV system on the diesel engines.
Hoses should be kept free of obstructions.

PCV SYSTEM

Article Text
1983 Mazda RX7
For www.iluvmyrx7.com
Copyright © 1998 Mitchell Repair Information Company, LLC
Sunday, August 26, 2001 04:59PM