MAN B&W L28/32H, Manual

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General
The engine is a turbocharged, single-acting, four-
stroke diesel engine of the trunk piston type with a
cylinder bore of 280 mm and a stroke of 320 mm, the
crankshaft speed is 720/750 rpm.
The engine can be delivered as an in-line engine with
5 to 9 cylinders.
Engine Frame
The engine frame which is made of cast iron is a
monoblock design incorporating the cylinder block,
the crankcase and the supporting flanges.
The charge air receiver, the cooling water jackets
and the housing for the camshaft and drive are also
integral parts of this one-piece casting.
The main bearings for the underslung crankshaft are
carried in heavy supports in the frame plating and are
secured by bearing caps. To ensure strong and
sturdy bedding of the caps, these are provided with
side guides and held in place by means of studs with
hydraulically tightened nuts. The main bearings are
equipped with replaceable shells which are fitted
without scraping.
The crankshaft guide bearing is located at the fly-
wheel end of the engine.
On the sides of the frame there are covers for access
to the camshaft, the charge air receiver and crank-
case. Some of the covers are fitted with relief valves
which will act, should oil vapours in the crankcase be
ignited, for instance in the event of a hot bearing.
Base Frame
The engine and alternator are mounted on a com-
mon base frame.
The rigid base frame construction can be embedded
directly on the engine seating or flexible mounted.
The engine part of the base frame acts as lubricating
oil reservoir.
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General Description B 10 01 1
96.12
L28/32H
Cylinder Liner
The cylinder liner is made of fine-grained, pearlite
cast iron and fitted in a bore in the engine frame.
Between the liner and the cylinder head and be-
tween the liner and the frame there are fitted replace-
able cast iron sealing rings. The liner is clamped by
the cylinder head and is guided by a bore at the
bottom of the cooling water space of the engine
frame. The liner can thus expand freely downwards
when heated during the running of the engine. Seal-
ing for the cooling water is obtained by means of
rubber rings which are fitted in grooves machined in
the liner.
Cooling water is supplied at the bottom of the cooling
water space between the liner and the engine frame
and leaves through bores in the top of the frame to
the cooling water guide jacket.
Cylinder Head
The cylinder head is of cast iron, made in one piece.
It has a central bore for the fuel injection valve and
bores for two exhaust valves, two inlet valves, safety
valve, indicator valve and cooling water.
The cylinder head is tightened by means of 6 nuts
and 6 studs, which are screwed into the engine
frame. The nuts are tightened by means of hydraulic
jacks.
The cylinder head has a screwed-on coaming which
encloses the valves.
The coaming is closed with a top cover and thus
provides an oil tight enclosure for the valve gear.
From the cooling water guide jacket, cooling water is
led through radial bores in the bottom of the head.
From the cooling water space and bores of the
cylinder head, the cooling water is led to a common
outlet.
Air Inlet and Exhaust Valves
The inlet and exhaust valve spindles are identical.
The valves are made of heat-resistant material. Hard