Open Library - открытая библиотека учебной информации

Открытая библиотека для школьников и студентов. Лекции, конспекты и учебные материалы по всем научным направлениям.


Строительство Mm (0.0087 in.) 0.27 mm (0.0106 in.)
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Valve Seating Surface Width


ОThe valve stem and guide must be in good condition, or this check will not be valid.

• If the valve seating pattern is not correct, repair the seat (see Valve Seat Repair).

• Measure the seat width [E] of the portion where there is no build-up carbon (white portion) of the valve seat with a vernier caliper.

• If the width is too wide, too narrow or uneven, repair the seat (see Valve Seat Repair).

[F] Good

[G] Too Wide [H] Too Narrow [J] Uneven

Inlet 0.5 ~ 1.0 mm (0.020 ~ 0.039 in.)

Exhaust 0.5 -1.0 mm (0.020 ~ 0.039 in.)

Measuring Valve-to-guide Clearance (Wobble method)

If a small bore gauge is not available, inspect the valve guide wear by measuring the valve to valve guide clearance with the wobble method, as indicated below.

• Insert a new valve [A] into the guide [B] and set a dial gauge against the stem perpendicular to it as close as possible to the cylinder head mating surface.

• Move the stem back and forth [C] to measure valve/valve guide clearance.

• Repeat the measurement in a direction at a right angle to the first.

• If the reading exceeds the service limit, replace the guide.

○The reading is not actual valve/valve guide clearance because the measuring point is above the guide.

Standard: Inlet Exhaust Service Limit: Inlet Exhaust

Valve/Valve Guide Clearance (Wobble Method)

0.02 ∼ 0.08 mm (0.0008 ∼ 0.0032 in.) 0.07 ∼ 0.14 mm (0.0028 ∼ 0.0055 in.)

Valve Seat Repair Repair the valve seat with the valve seat cutters.