Toro Groundsmaster 455-D Service Manual page 68

8. Check the protrusion of the swirl chambers
(Fig. 68, A).
Protrusion: 0 to 0.03 mm
Achieve this dimension by machining faces (a) and (b).
9. Check the valve recess (B).
Exhaust: 0.9 to 1.45 mm
Inlet: 0.5 to 1.05 mm
Achieve this dimension by machining the valve seats.
10. Lap in the valves.
11. Re-install the valves.
IMPORTANT: If the cyl ind er head has been
machined, fit compensating washers under the
valve springs. (See Identification and Specifications
section.)
12. Install the shims as removed in step 2. If replacing
cylinder head or if cylinder head has been machined,
install a basic shim (Fig. 69, Item 6) (2.425 mm thick) to
each valve stem and check that each shim is higher than
the spring cup (Item c). If a shim is not higher than the
cup, grind the top of the cup (Item c).
13. Re-install the tappets.
14. Oil the camshaft bearings.
15. Install the camshaft, with the DIST mark at the timing
gear end.
16. Progressively tighten the bearing caps to a torque
of 17.5 Nm (13 ft-lb). The bearing caps have cast-in
markings for correct installation.
Engine
c
Page 3 - 50 Rev. B
Figure 68
Figure 69
Figure 70
Groundsmaster 455-D