Kohler Command PRO ECV630 Service Manual page 109

Valve Stem Seals
These engines use valve stem seals on intake valves
and on exhaust valves. Use a new seal whenever valve
is removed or if seal is deteriorated or damaged in any
way. Never reuse an old seal.
Assemble Cylinder Heads
Prior to installation, lubricate all components with engine
oil, paying particular attention to lip of valve stem seal,
valve stems, and valve guides. Install following items in
order listed below using a valve spring compressor.
• Intake and exhaust valves.
• Valve spring retainers.
• Valve springs.
• Valve spring caps.
• Valve spring keepers.
Install Cylinder Heads
Torque Sequence
#1
NOTE: Cylinder heads must be attached with original
type of mounting hardware, using either screws,
or mounting studs with nuts and washers. Do
not intermix components.
NOTE: Match numbers embossed on cylinder heads
and crankcase.
1. Check to make sure there are no nicks or burrs on
sealing surfaces of cylinder head or crankcase.
Heads secured with mounting studs, nuts, and washers:
2. If all of studs were left intact, go to Step 6. If any
studs were disturbed or removed, install new studs
as described in Step 3. Do not use/reinstall any
loosened or removed studs.
3. Install new mounting stud(s) into crankcase.
a. Thread and lock mounting nuts together on
smaller diameter threads.
b. Thread opposite end of stud, with preapplied
locking compound, into crankcase, until specified
height from crankcase surface is achieved. When
threading in studs, use a steady tightening motion
without interruption until proper height is
obtained. Otherwise frictional heat from engaging
threads may cause locking compound to set up
prematurely.
24 690 02 Rev. D
Studs closest to lifters must have an exposed height of
75 mm (2 15/16 in.).
Studs furthest from lifters must have an exposed height
of 69 mm (2 3/4 in.).
4. Check that dowel pins are in place and install a new
5. Install cylinder head. Match numbers on cylinder
6. Lightly lubricate exposed (upper) threads of studs
Heads secured with screws:
2. Install a new cylinder head gasket (part number
3. Install cylinder head and start screws.
4. Torque screws in 2 stages; first to 22.6 N·m (200 in.
Install Push Rods and Rocker Arms
NOTE: Push rods should always be installed in same
1. Note mark or tag identifying push rod as either
#2
2. Apply grease to contact surfaces of rocker arms and
3. Torque screws to 11.9 N·m (105 in. lb.).
4. Use a spanner wrench or rocker arm lifting tool to lift
5. Repeat above steps for remaining cylinder. Do not
6. Rotate crankshaft to check for free operation of
Check Assembly
Important: Rotate crankshaft a minimum of 2 revolutions
to check longblock assembly and overall proper
operation.
Install Spark Plugs
1. Check gap using wire feeler gauge. Adjust gap to
2. Install plug into cylinder head.
3. Torque plug to 27 N·m (20 ft. lb.).
KohlerEngines.com
c. Remove nuts and repeat procedure as required.
cylinder head gasket (part number facing up).
heads and crankcase. Make sure head is flat on
gasket and dowel pins.
with engine oil. Install a flat washer and nut onto
each of mounting studs. Torque nuts in 2 stages; first
to 16.9 N·m (150 in. lb.), then finally to 33.9 N·m
(300 in. lb.), following sequence.
facing up).
lb.), then finally to 41.8 N·m (370 in. lb.), following
sequence.
position as before disassembly.
intake or exhaust and cylinder 1 or 2. Dip ends of
push rods in engine oil and install, making sure that
each push rod ball seats in its hydraulic lifter socket.
rocker arm pivots. Install rocker arms and rocker arm
pivots on one cylinder head, and start screws.
rocker arms and position push rods underneath.
interchange parts from cylinder heads.
valve train. Check clearance between valve spring
coils at full lift. Minimum allowable clearance is 0.25
mm (0.010 in.).
0.76 mm (0.03 in.).
Reassembly
109