Engine Mechanical - Overhaul - 1.8L (Bp): Removal & Installation Mazda MX-5 NB рестайлинг

VALVE GUIDE REPLACEMENT

Note. Intake and exhaust valve guides are different.

Scheme 23

1. Remove the valve guide from the combustion chamber side by using the SST .

Scheme 24

Scheme 25

1. Assemble the SSTs so that depth L is as specified. Depth L 18.3-18.9 mm {0.721-0.744 in}
2. Tap the valve guide in from the side opposite the combustion chamber until the SST contacts the cylinder head.
3. Verify that the valve guide projection height (dimension) is as specified. Standard Height 18.3-18.9 mm {0.721-0.744 in}

Scheme 26

Scheme 27

Scheme 28

1. Measure the seat contact width. As necessary, resurface the valve seat using a 45 ° valve seat cutter and/or resurface the valve face. Standard Width 0.8-1.4 mm {0.032-0.055 in}
2. Verify that the valve seating position is at the center of the valve face. If the seating position is too high, correct the valve seat using a 70 ° cutter, and a 45 ° cutter. If the seating position is too low, correct the valve seat using a 45° cutter.
3. Inspect the sinking of the valve seat. Measure the protruding length (dimension L) of the valve stem. Replace the cylinder head as necessary. Standard Dimension L IN: 45.0 mm {1.772 in} EX: 45.0 mm {1.772 in} Maximum Dimension L IN: 45.6 mm {1.795 in} EX: 45.6 mm {1.795 in}

Scheme 29

Scheme 30

1. Apply pressing force to the pressure spring and measure the spring height. Replace the valve spring as necessary. Pressing Force IN: 172.60-195.15 N {17.6-19.9 kgf, 38.72-43.78 lbf} EX: 172.60-195.15 N {17.6-19.9 kgf, 38.72-43.78 lbf} Standard Height IN: 39.5 mm {1.56 in} EX: 39.5 mm {1.56 in}
2. Measure the out-of-square of the valve spring. Replace the valve spring as necessary.

VALVE SPRING OUT-OF-SQUARE SPECIFICATIONS

Scheme 31

Scheme 32

Scheme 33

1. Set the No.1 and No.5 journals on V-blocks. Measure the camshaft runout. Replace the camshaft as necessary. Runout 0.03 mm {0.0012 in} max.
2. Measure the cam lobe height at the two points as shown. Replace the camshaft as necessary. CAM LOBE STANDARD HEIGHT SPECIFICATIONS Camshaft BP - mm {in} BP with TC - mm {in} IN 44.3 {1.744} 44.8 {1.764} EX 44.9 {1.768} CAM LOBE MINIMUM HEIGHT SPECIFICATIONS Camshaft BP - mm {in} BP with TC - mm {in} IN 44.1 {1.736} 44.6 {1.756} EX 44.7 {1.760}
3. Measure the journal diameters in X and Y directions at the two points (A and B) as shown. Replace the camshaft as necessary. Standard Diameter 25.940-25.965 mm {1.0213-1.0222 in} Minimum Diameter 25.910 mm {1.0201 in}

Scheme 34

1. Position a plastigage on the top of the journals in the axial direction.
2. Install the camshaft cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER HEAD DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S39131026472005080800000) , «CAMSHAFT DISASSEMBLY NOTE»(ref-182481-S12850843802005080800000) .)
3. Remove the camshaft cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER HEAD DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S39131026472005080800000) , «CAMSHAFT DISASSEMBLY NOTE»(ref-182481-S12850843802005080800000) .)
4. Measure the oil clearance. Replace the cylinder head as necessary. Standard Clearance 0.035-0.081 mm {0.0014-0.0031 in} Maximum Clearance 0.15 mm {0.006 in}

Scheme 35

1. Install the camshaft cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER HEAD DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S39131026472005080800000) , «CAMSHAFT DISASSEMBLY NOTE»(ref-182481-S12850843802005080800000) .)
2. Measure the camshaft end play. Replace the cylinder head or camshaft as necessary. Standard End Play 0.057-0.127 mm {0.0023-0.0049 in} Maximum End Play 0.20 mm {0.008 in}
3. Remove the camshaft cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER HEAD DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S39131026472005080800000) , «CAMSHAFT DISASSEMBLY NOTE»(ref-182481-S12850843802005080800000) .)

Scheme 36

Scheme 37

1. Measure the diameter of each tappet bore. Standard Diameter 30.000-30.025 mm {1.1811-1.1820 in}
2. Measure the diameter of each tappet. Standard Diameter 29.959-29.975 mm {1.1795-1.1801 in}
3. Calculate the clearance between the tappet and the related tappet bore. Replace the tappet or cylinder head as necessary. Standard Clearance 0.025-0.066 mm {0.00099-0.00259 in} Maximum Clearance 0.180 mm {0.0071 in}

Scheme 38

Scheme 39

1. Measure the distortion of the cylinder block top surface in the six directions as shown. Repair by grinding or replace as necessary. Cylinder Block Distortion 0.15 mm {0.006 in} max. Cylinder Block Height 221.5 mm {8.720 in} Grinding 0.20 mm {0.008 in} max.
2. Measure the cylinder bores in X and Y directions at 35 mm {1.38 in} below the top surface.
3. If the cylinder bore exceeds the wear limit, replace the cylinder block or rebore the cylinder and install the oversize pistons so that the specified piston-to-cylinder clearance is obtained.