Mitsubishi L2C Service Manual

INSPECTION AND REPAIR OF BASIC ENGINE
6-5
1.6 Measuring perpendicularity and free length
of valve spring
Measure the perpendicularity and free length of the valve
spring. If the limit is exceeded, replace the valve spring with
a new one.
Squareness and free length of spring
1.7 Lapping valve and valve seat
Always lap the valve against the valve seat after refacing the
valve seat or after replacing the valve.
(1) Apply a thin coat of lapping compound evenly to the
valve face.
Note: (a) Do not allow the compound to adhere on the
valve stem.
(b) Compound spreads more evenly if it is mixed
with a small amount of engine oil.
(c) Use medium-grain compound (120 to 150 mesh)
for initial lapping, then use fine-grain compound
(200 mesh or finer) for finishing.
(2) Use a valve lapper for lapping. Strike the valve against
the valve seat while rotating the valve little by little.
(3) Wash off the compound using diesel fuel.
(4) Coat the contact surface of the valve with engine oil,
then lap the valve again.
(5) Check valve-to-seat contact.
Lapping valve and valve seat
Item Standard Limit
Free length
40 mm
[1.57 in.]
38.5 mm
[1.516 in.]
Perpendicularity
θ = 2.0 °or less
Δ (gap) = 1.4 mm
[0.055 in.] or less
Lf = 40 mm [1.57 in.]
△ = 2.0
mm
[0.079 in.]
over entire
length
Set length/set
force
35.5 [1.3976] / 55.3 to 61.2 N
{5.64 to 6.24 kgf}
[12.4 to 13.8 lbf]
-15 %
28.0 [1.1024] / 138.2 to 152.9 N
{14.09 to 15.59 kgf}
[31.1 to 34.4 lbf]
ٌ
Lf
ǰ
Free length
Spring perpendicularity (gap)
Valve lapper
Compound

Mitsubishi L2C Specifications

General

Brand	Mitsubishi
Model	L2C
Category	Engine
Language	English