39
Technical description
Engine
These engines are four-stroke, straight six marine diesel engines with overhead valves. They are fluid-cooled
and equipped with turbochargers. The inlet air to the engine is cooled by a seawater-cooled charge air cooler
(CAC) after compression in the turbo (TAMD71 and TAMD72 have double charge air coolers).
The engines have piston cooling* (oil-cooled pistons). The lubrication system has a full flow oil filter, and the
TAMD63 also has a partial flow (by-pass) filter. This by-pass filter is an accessory for other engines.
The cooling system is divided into a freshwater and a seawater system. The seawater cools the freshwater sys-
tem via a heat exchanger (TAMD71 and TAMD72 have double heat exchangers).
Cylinder heads
The engines have two cylinder heads, each covering
three cylinders, and are made of special-alloy cast
iron. The cylinder head gaskets are made of solid
sheet steel and have special rubber sealing rings in-
side for oil and coolant channels.
Valve system
The camshaft is journalled in seven bearings and is
driven by the timing gears. The camshaft actuates
the inlet and outlet valves in the cylinder heads via
lifters, push rods and rockers.
In the TAMD71 and TAMD72, these valves have
double valve springs.
Cylinder block
The cylinder block is made of special alloy cast iron
and cast in one piece. The cylinder liners are of the
wet type, can be replaced, and have a flame barrier
which considerably increases the service life of the
cylinder head gaskets.
Crankshaft
The heavy-duty crankshaft is extremely strong and is
journalled in seven main bearings. This shaft is stati-
cally and dynamically balanced and tempered ac-
cording to a special method (nitrocarburization). This
increases the fatigue strength and gives the bearing
journals an extremely hard surface.
The journal at the front of the crankshaft has been
ground to a polygonal shape. A polygon joint can
withstand the stresses from the vibration damper (ex-
tra pulley or disengageable clutch) considerably bet-
ter than a keyed joint.
Pistons
The pistons, which are made of an aluminum alloy,
have two compression rings and one oil ring. The up-
per compression ring is coated with molybdenum
(both compression rings in the TAMD71 and
TAMD72), which helps reduce oil consumption and
the risk of ring seizing.
The pistons are oil-cooled to reduce the risk of cok-
ing at high load. Piston cooling increases the service
life of pistons, piston rings and cylinder liners and re-
duces oil consumption.
The engine’s combustion chambers are entirely con-
fined to the piston crowns.
Piston cooling
To Next Page
Loading...