Lotus Elise Service Notes page 193

ENGINE
Valve seats - refacing
~ CAUTION: Renew worn valve guides
/ ! \ before refacing valves and seats.
1. Check condition of valve seats and existing
valves that are to be re-used.
3. Lap each valve to seat using fine grinding
paste.
4. Apply Prussian Blue to valve seat, insert valve
and press it into position several times without
rotating. Remove and check valve for even and
central seating:
Seating position shown by blue should be in
centre of valve face.
A
8 R M 3 5 3 0 B
NOTE: Triple angle valve seat illustrated
2. Recut valve seats and use pilot MS120-6 and
the following cutters:-
MS76-120 - 15° - Triple angle valve seats
only.
MS76-111 60° - To narrow valve seats and
obtain seat widths.
MS76-122 45° - Make final cut and remove any
burrs.
Valve seat:
Angle = 45°
Width A =
Except triple angle valve seats:
Inlet - 1.5 mm
Exhaust - 1.5 mm
Triple angle valve seats:-
Inlet - 1.0 to 1.4 mm
Exhaust 1.4 to 1.8 mm
Valve face angle B:
Inlet = 45°
Exhaust = 45°
8 R M 3 5 3 1
5. Check valve stem fitted height A:
K8:
New = 38.95 to 40.81 mm
Service limit = 41.06 mm
K16:
New = 38.93 to 39.84 mm
Service limit = 40.10 mm
If valve stem fitted height is above service limit, fit
new valve and re-check, if still over limit, renew
valve seat insert.
All engines
6. Remove all traces of grinding paste on
completion.
~ CAUTION: Inserts must not stand proud of
/ ! \ combustion face of head on completion of
recutting operation.
5 6 OVERHAUL