Cylinder Head Assembly; General Description - Perkins New 1000 Series Workshop Manual

New 1000 Series
12

Cylinder head assembly

12

General description

In a diesel engine there is little carbon deposit and for
this reason the number of hours run is no indication of
when to overhaul a cylinder head assembly. The
factors which indicate when an overhaul is necessary
are how easily the engine starts and its general
performance.
The cylinder head assembly has two valves fitted for
each cylinder, each fitted with single valve springs.
The ports for the inlet and exhaust are on the right
side of the cylinder head.
The face angle of the valves is either 45° or 30°. The
angle of the valve seats in the cylinder head is either
46° or 31°.
The valves move in phosphated steel guides which
can be renewed. The exhaust valve guide has a
counterbore to prevent seizure of the valve stem
caused by a build up of carbon under the head of the
valve.
Both valve stems are fitted with oil seals that fit over
the top of the valve guides.
The engines have steel valve seat inserts fitted in the
cylinder head for both inlet and exhaust valves.
Workshop Manual, TPD 1350, issue 3
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