Westerbeke 8.0KW-60Hz Service Manual page 24

ENGINE-DISASSEMBLY, INSPECTION AND ASSEMBLY
VALVES
1. Check the valve face for correct contact. If contact is
uneven or incomplete, reface the valve seat.
2. If the margin is less than specified, replace the valve.
STANDARD VALUE:
INTAKE 1.0mm (.0394In)
EXHAUST 1.Smm (.OS9In)
LIMIT:
INTAKE O.Smm (.0197In)
EXHAUST 1.0mm (.0394In)
3. Measure the valves total length. If the measurement is less
than specified, replace the valve.
STANDARD VALUE:
INTAKE 100.7Smm (3.969In)
EXHAUST 101.0Smm (3.98In)
LIMIT:
INTAKE 100.2Smm (3.9Sln)
EXHAUST 100.5Smm (3.9Sln)
CONTACT MUST
BE MAOE IN THE
CENTER OF THE FACE
VALVE SPRINGS
- --T--
VALVE
LENGTH
1. Measure the valve springs free height. If the
measurement is less than specified, replace the spring.
STANDARD VALUE:
INTAKE 4S.1mm (l.81In)
EXHAUST 4S.8mm (1.84In)
LIMIT:
EXHAUST 4S.3mm (l.82In)
2. Measure the squareness of the spring. If the measurement
exceeds the specified limit, replace the spring.
STANDARD VALUE: 2' or 10 ••
LIMIT: 2' or 10 ..
MEASURING SPRING SQUARENESS
MEASURING SPRING
FREE HEIGHT
VALVE GUIDES
1. Measure the clearance between the valve guide and the
valve stem. If the clearance exceeds the specified limit,
replace either or both components.
STANDARD VALUE:
INTAKE 0.020· O.OSOmm (.00078 •• 00197In)
EXHAUST O.OSO· 0.08Smm (.00197 •• 0033In)
LIMIT:
INTAKE 0.10mm (O.00394In)
EXHAUST O.lSmm (0.00S9In)
CHECKING VALVE
STEM 0.0.
VALVE SEATS
MEASURING VALVE
GUIDE 1.0.
1. Assemble the valve, then measure the valve stem
projection between the end of the valve stem and the
spring seating surface. If the measurement exceeds the
specified
limi~
replace the valve seat.
STANDARD VALUE:
INTAKE 43.70mm (l.72In)
EXHAUST 43.30mm (l.701n)
LIMIT:
INTAKE 44.20mm (l.74In)
EXHAUST 43.80mm (l.72Sln)
MEASURING VALVE
STEM PROJECTION
VALVE SEAT CORRECTION
VALVE STEM
PRDJECTION
I
1. Before correcting the valve sea~ check the clearance
between the valve guide and valve. If necessary, replace
the valve guide.
2. Using the appropriate special tool or seat grinder, correct
the valve seat to achieve the specified seat width and
angle.
3. After correcting the valve seat, lap the valve and valve
sear using lapping compound. Then. check the valve stem
projection:
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65°
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WESTERBEKE
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Engines & Generators
17
4&°