Disassembly and Reassembly
CYLINDER HEAD AND VALVES
COMPONENTS
REMOVAL
1. Using the special tool, Cylinder Head Bolt Wrench (09221 - 32001), remove the cylinder head bolts as shown in the illustration.
2. Using the special tool, Valve Spring Compressor (09222- 28000,09222-28100), remove the retainer lock. Next remove the spring retainer, valve spring, spring seat and valve.
NOTE: Keep these parts in order so that they can be reinstalled in their original positions.
3. Remove the valve stem seals with pliers, and discard.
NOTE: Do not reuse the valve stem seals.
INSPECTION
Cylinder head
1. Check the cylinder head for cracks, damage and coolant leakage. If cracked, replace the cylinder head.
2. Remove scale, sealing compound and carbon deposits completely. After cleaning oil passages, apply compressed air to make certain that the passages are not clogged.
3. Check the cylinder head gasket surface for flatness by using a straight edge in the direction of A, B, ... as shown.
If flatness exceeds service limit in any direction, either replace the cylinder head, or lightly machine the cylinder head gasket surface.
Flatness of cylinder head gasket surface
[Standard dimension]
Less than 0.05 mm (0.002 in.)
[Limit]
0.1 mm (0.0039 in.)
Valves
1. Using a wire brush, clean the valve thoroughly.
2. Check each valve for wear, damage and distortion of head and stem at B. Repair or correct it necessary.
If stem end A is pitted or worn, resurface as necessary. This correction must be limited to a minimum. Also resurface the valve face.
Replace the valve if the margin has decreased to less than the service limit.
Margin
[Standard dimension]
Intake 1.0 mm (0.039 in.)
Exhaust 1.5 mm (0.059 in.)
[Limit]
Intake 0.7 mm (0.028 in.)
Exhaust 1.0 mm (0.039 in.)
Valve Springs
1. Check the valve spring free length and tension. If they exceed the service limit, replace the spring.
2. Using a square, test the squareness of each spring. If the spring is excessively out of square, replace it.
Valve spring
[Standard Value]
Free height 48.3 mm (1.902 in.)
Load 300 N (66 lb)/40 mm (1.575 in.)
Out of square 1.5° or less
[Limit]
Free hight -1.0 mm (-0.039 in.)
Out of square 4°
Valve Guides
Check the valve stem-to-guide clearance. If the clearance exceeds the service limit. replace the valve guide with the next oversize part.
Valve stem-to-guide clearance
[Standard dimension]
Intake 0.020-0.047 mm (0.0008-0.0019 in.)
Exhaust 0.050-0.085 mm (0.0020-0.0033 in.)
[Limit]
Intake 0.1 mm (0.0039 in.)
Exhaust 0.15 mm (0.0059 In.)
Valve Seat Insert
Check the valve seat for evidence of overheating and improper contact with the valve face. Recondition or replace the seat if necessary.
Before reconditioning the seat, check the valve guide for wear. If the valve guide is worn, replace it, then recondition the seat. Recondition the valve seat with a valve seat grinder or cutter. The valve seat contact width should be within specifications and centered on the valve face.
Valve Seat Insert Replacement Procedure
1. Any valve seat insert that has been worn over the service limit should be removed at normal temperature after cuffing away most of the insert wall, using valve seat cutters, as shown In Fig. "A".
2. After removing the seat insert, machine the seat insert bore using a reamer or a cutter. Cut to the size shown in the table.
3. Heat the cylinder head to about 250°C (480°F) and press in the oversize seat insert. The oversize seat insert should be at normal room temperature for installation. After installation of a new valve seat insert, resurface the valve seat using the same procedure as in paragraph 1. in Valve Seat Insert.
Valve Guide Replacement Procedure
The valve guide Is installed using a press fit. Using a Valve Guide
Installer (09222-21 200A, 09222-21 200B) or suitable tool, replace the valve guide by the following procedure.
1. Using the push rod of the Valve Guide Installer, push the valve guide out toward the cylinder block with a press.
2. Machine the valve guide insert hole in the cylinder head to the specified oversize of the new valve guide.
3. Using the Valve Guide Installer or suitable tool, press fit the valve guide. The use of the valve guide installer makes it possible to press fit the valve guide to a predetermined height. The valve guide should be installed from the top of the cylinder head. Note that intake and exhaust valve guides are different in length [45.5 mm (1.791 in.) for intake and 50.5 mm (1.988 in.) for exhaust.]
4. After the valve guides have been installed, insert new valves and check the clearance.
5. Whenever valve guides are replaced, check for valve to seat contact and recondition the valve seats as necessary.
INSTALLATION
NOTE:
1) Clean each part before assembly.
2) Apply angina oil to eliding and rotating parts.
1. After installing the spring seat, fit the stem seal onto the valve guide.
To install, fit the seal in by lightly tapping the Special Tool, Valve Stem Oil Seal Installer (09222-28200).
The seal is installed in the specified position by means of the special tool. Incorrect installation of the seal will adversely affect the lip I.D. and eccentricity, resulting in oil leakage down the valve guides. When installing, therefore1 be careful not to twist the seal. Do not reuse old stem seals.
2. Apply engine oil to each valve. Insert the valves Into the valve guides. Avoid inserting the valve into the seal with force. After insertion, check to see if the valve moves smoothly.
3. Install springs and spring retainers.
Valve springs should be installed with the enamel coated side toward the valve spring retainer.
4. Using the special tool, Valve Spring Compressor (09222-28000, 09222-28100), remove the retainer lock. Next remove the spring retainer, valve spring, spring seat and valve.
NOTE: Keep these parts in order so that they can be reinstalled in their original positions.
5. Clean all gasket surfaces of the cylinder block and cylinder head.
6. Install a new cylinder head gasket onto the cylinder head assembly. Do not apply sealant to the gasket and do not reuse the old cylinder head gasket.
Tightening Sequence:
7. Using the special tool, Cylinder Head Bolt Wrench (09221 - 32001), install the cylinder head bolts as shown in the illustration.
Tightening torque
Cylinder head bolt [cold engine]
105-115 Nm (1050-1150 kg.cm, 76-83 lb.ft)