Sunbeam ALPINE I SERIES: APLINE II SERIES, Workshop Manual

Page: 62 / 413

I st re-issue
Page 24
cylinder head is heated to the proper temperature.
THEY CANNOT BE DRIVEN OUT OF A COLD
CYLINDER HEAD.
New valve guides must have a proper interference
fit and can only be installed when the cylinder head
has been heated to the proper fitting temperature.
This usually requires the fitting of guides having an
outside diameter of -001• (·025 mm.) larger than
the guides that are removed. The correct inter­
ference for these valve guides is given in the Data
Section under "Valves".
The valve guide depth positioning clrclips should be
fitted to the valve guides before tapping the valve
guides into the cylinder head.
The sharp edge of the top end of the valve guide
must not be damaged as this edge is used to scrape
excess oil from the valve stem.
After fitting, the valve guides should be reamed
with a spiral fluted reamer, to give a valve guide
bore diameter of ·3125-·3135 ins. (7·94-7·96 mm.).
Seatinc Width
•050" (1 ·27mm.) to
•070" (1 •7Bmm)
,eog·p
Inlet valYa
correctly seated
Incorrect SntinJ
(Pocketed valve)
Fig. 24.
Valve
seating
VALVES
To reface
WSM. 124
Section B (Engine)
If, on examination of the valves it appears unlikely
that they would clean up satisfactorily with ordinary
grinding In, they must be refaced. If the seatings
are also in bad condition they must be recut, but
Fig. 25. Use of 45 ° volve seot cutter
2791.
Fig, 26. Use
of
I 5 °
valve
seat cutter
Fig, 27. Use of75
° valve
seat
cutter
.J