HOW WEAR ATTACKS VALVE FACE
Even in normal use the intake and the exhaust valves
quick fifteen minute trip to the shopping center, a single
valve may open and close 10,000 times. Extreme
temperatures scorch it many times each second.
Violent explosions and powerful spring tension pound
the red hot (1600 .) valve head. Hot gases under
F
tremendous pressure swirl past it. Carbon deposits form
on the face, preventing the valve from seating properly
or cooling efficiently. As a result, the valves-particularly
the exhaust valves-become pitted, burned, warped and
grooved. No longer concentric with the valve seat, they
leak compression and fail to dissipate heat. Engine
efficiency and economy nosedive.
. . . . VALVE STEM
But it's not only the valve face that wears. The valve
stems travel a mile or more in their guides during that
short shopping trip, They wear at the top of the guides
and at the bottom. Valve ends also wear and must be
squared.
. . . . VALVE SEAT
The valve seat also wears. Hot gases burn it. Carbon
particles which retain heat pit it. The valve guide wears
in a corresponding position to the valve stem. Between
stem and guide, carbon residues form which cause the
valves to stick. To insure top performance, both valve
face, valve seat and valve guide must be reconditioned.
. . . . and VALVE GUIDE
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