Vanguard BIG BLOCK M540000, Repair Manual, Page: 95 / 168

11. For engines equipped with single-angle valve seats, see
Figure 113 and proceed as follows:
NOTE: Carefully read manufacturer's directions for proper
assembly and use of valve seat cutting tool.
A. Install the proper sized pilot in the intake valve guide.
NOTE: Do not drop the cutter onto the valve seat during
installation or removal, as the blades may cause seat damage
that requires additional cutting.
NOTE: Applying too much pressure or rotating the cutter too
fast will produce chatter marks that adversely affect sealing
integrity. Rotate the cutter slowly, so that it takes about three
seconds to make one complete rotation.
113
B. Install the 45° base angle cutter and cut the seat
contact area until it is approximately 0.047-0.063
inches (1.19-1.59 mm) wide.
C. Use low pressure compressed air to thoroughly
remove all cutting chips and metal shavings.
Remove pilot from valve guide.
D. Lap the valve face and seat a second time to verify
location and width of the seat contact area.
E. If the seat contact area is too narrow, recut using the
45° base angle cutter.
F. Repeat steps 8 and 10 on the exhaust valve.
96 vanguardpower.com