Sunbeam ALPINE I SERIES: APLINE II SERIES, Workshop Manual, Page: 59 / 413

WSM.124
Section B (Engine)
Fig. 19.
Tightening diagram for cylinder head
DECARBONISING
When the cylinder head has been removed for
decarbonising the complete set of valves should be
removed for cleaning, inspection and refacing,
(detailed instructions for these operations are given
elsewhere in this section). The valve guides should
also be checked for wear on their internal diameters
and in this respect reference should be made to
"VALVE GUIDES-TO RENEW".
When removing the carbon from each piston crown,
it is always advisable to leave a ring of carbon
adjacent to the cylinder bore as this helps to
preserve a good seal, and to conserve oil. A
convenient method of doing this is to turn the
engine until the piston is slightly below the top
dead centre position, and insert an old piston ring
of correct size in the bore, and press down on the
piston. In this way all the carbon within the old
piston ring may be removed, leaving a ring of
carbon around the piston edge.
Remove carbon from the tops of the pistons, the
combustion chambers in the cylinder head and also
from the valve ports. With a suitable scraper clean
out the inside of the exhaust manifold.
Place clean rag in the exposed area of the tappet
chamber, as no carbon should be allowed to enter.
Remove all loosened carbon, preferably by use of a
compressed air line.
Care must be taken when decarbonising the tops of
the pistons, these being of aluminium alloy. No
2nd re-issue
Page
21
pointed instrument or emery cloth may be used
Do not on any account use abrasives for removing
carbon, or damage will result.
Having attended to the preceding operations and
given the valves and seatings any attention that may
be required, the engine may be reassembled.
VALVES
To remove
To assist in this operation it is recommended that a
valve spring compressor (Churchill Tool D.6513)
be used, as shown in Fig. 20.
Remove cylinder head.
Using the valve spring compressor, remove the
split coned cotters. When carrying out this
Fig.
20. Use
of valve spring tool
operation care should be taken to ensure that no
damage is caused to the valve stem by the hardened
steel cotters and spring cups.
Release valve spring compressor and lift off cups and
dual valve springs.
Remove the valves.