Mitsubishi 4D30, 4D31, 4D32, 4DR5 & 6DR5 Engine Shop Manual

Manuals: Shop Manual
General
Engine
Lubrication
Fuel and Engine control
Cooling
Engineer electrical
Clutch
Transmission
Special Equipment

This manual contains the specifications, construction, operation, adjustment and service procedures of the diesel engine for service mechanics engaged in servicing of the Mitsubishi diesel engines.

Please make the most of this manual to perform correct servicing and operations.
Note that some of the contents of this manual are subject to change owing to improvements, etc. that may be introduced after publication of the manual.
The combustion chamber consists of the cylinder head and toroidal pistons, hole type injection nozzles and sheathed type glow plugs being installed in the cylinder head.
Combustion occurs when the fuel is directly injected into the combustion chamber with the power operating the piston directly.

The combustion chamber in the Engines is formed by the lobes-shaped main combustion chamber in the piston head and Mitsubishi’s own bell-shaped swirl chamber. A chamber jet is press-fitted into the swirl chamber that is made of material with little thermal expansion and good thermal conductivity. Also installed in the chamber are the sheathed glow plug and throttle injection nozzle.

The upward movement of the piston during the compression stroke imparts a violent swirling motion to the air charged into the swirl chamber, to which fuel is injected for combustion. As the combustion goes on, the gas moves from the swirl to main combustion chamber where it is mixed with the air present. And further combustion occurs.