Engine Mechanical - Overhaul - 1.8L (Bp): Other Mazda MX-5 NB рестайлинг

DISMOUNTING

1. Dismount in the reverse order of mounting.

CYLINDER BORE

CYLINDER BORE SPECIFICATIONS

Wear Limit

1. 0.15 mm {0.006 in}

Scheme 124

1. Apply compressed air to oil jet valve A and verify that air passes through oil jet valve B. If not, replace the oil jet valve. Air Pressure 167-225 kPa {1.7-2.3 kgf/cm 2 , 25-32 psi}
2. Inspect the oil jet nozzle for clogs. Replace the nozzle as necessary.

Piston Diameter

PISTON DIAMETER SPECIFICATIONS

Scheme 125

Main Journal

MAIN JOURNAL BEARING SPECIFICATIONS

Out-of-Round

1. 0.05 mm {0.002 in} max.

Crank Pin

CRANK PIN BEARING SPECIFICATIONS

Out-of-Round

Scheme 126

1. 0.05 mm {0.002 in} max.

Scheme 127

1. Position plastigage on the top of the journals in the axial direction.
2. Install the main bearing 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 main bearing 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 main journal oil clearance. If the clearance exceeds the maximum, replace the main bearing or grind the main journal and install the undersize bearings so that the specified oil clearance is obtained. Standard Clearance 0.018-0.036 mm {0.0008-0.0014 in} Maximum Clearance 0.10 mm {0.0039 in} MAIN JOURNAL BEARING SPECIFICATION Bearing Size - mm {in} Bearing Thickness - mm {in} Standard 2.007-2.025 {0.0791-0.0797} 0.25 {0.01} Undersize 2.133-2.137 {0.0840-0.0841} 0.50 {0.02} Undersize 2.258-2.262 {0.0889-0.0890} 0.75 {0.03} Undersize 2.383-2.387 {0.0938-0.0940}

Scheme 128

1. Install the main bearing cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER BLOCK DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S02305675602005080800000) , «MAIN BEARING CAP ASSEMBLY NOTE»(ref-182481-S40893474272005080800000) .)
2. Measure the crankshaft end play. If the end play exceeds the maximum, replace the thrust bearing or grind the crankshaft and install an undersize bearing so that the specified end play is obtained. Standard End Play 0.080-0.282 mm {0.0032-0.0111 in} Maximum End Play 0.30 mm {0.012 in} THRUST BEARING SPECIFICATION Bearing Size - mm {in} Bearing Thickness - mm {in} Standard 2.500-2.550 {0.0985-0.1003} 0.25 {0.01} Undersize 2.625-2.675 {0.1034-0.1053} 0.50 {0.02} Undersize 2.750-2.800 {0.1083-0.1102} 0.75 {0.03} Undersize 2.875-2.925 {0.1132-0.1151}
3. Remove the main bearing cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER BLOCK DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S02305675602005080800000) , «MAIN BEARING CAP DISASSEMBLY NOTE»(ref-182481-S21337285972005080800000) .)

Scheme 129

1. Measure each connecting rod for bending and distortion. Replace the connecting rod as necessary. Bending 0.05 mm {0.0020 in} max. /50 mm {1.97 in} Distortion 0.07 mm {0.0028 in} max. /50 mm {1.97 in} Center-to-Center Distance 132.85-132.95 mm {5.2304-5.2342 in}

Scheme 130

1. Position a plastigage on the top of the journals in the axial direction.
2. Install the connecting rod cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER BLOCK DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S02305675602005080800000) , «PISTON AND CONNECTING ROD ASSEMBLY NOTE»(ref-182481-S02594595822005080800000) .)
3. Remove the connecting rod cap.
4. Measure the crankpin oil clearance. If the clearance exceeds the maximum, replace the connecting rod bearing or grind the crankpin and use undersize bearings so that the specified clearance is obtained. Standard Clearance 0.028-0.048 mm {0.0012-0.0018 in} Maximum Clearance 0.10 mm {0.0039 in} CONNECTING ROD BEARING SPECIFICATIONS Bearing Size - mm {in} Bearing Thickness - mm {in} Standard 1.504-1.520 {0.05922-0.05984} 0.25 {0.01} Undersize 1.631-1.635 {0.06422-0.06436} 0.50 {0.02} Undersize 1.756-1.760 {0.06914-0.06929} 0.75 {0.03} Undersize 1.881-1.885 {0.07406-0.07421}

Scheme 131

1. Install the connecting rod cap. (Refer to «ENGINE DISASSEMBLY/ASSEMBLY»(ref-182481-S28828331372005080800000) , «CYLINDER BLOCK DISASSEMBLY/ASSEMBLY (II)»(ref-182481-S02305675602005080800000) , «PISTON AND CONNECTING ROD ASSEMBLY NOTE»(ref-182481-S02594595822005080800000) .)
2. Measure the connecting rod large end side clearance. Replace the connecting rod and cap as necessary. Standard Clearance 0.110-0.262 mm {0.005-0.010 in} Maximum Clearance 0.30 mm {0.012 in}
3. Remove the connecting rod cap.

Scheme 132

1. Inspect the oscillation torque as shown. If the large end does not drop by its own weight, replace the piston or the piston pin.

Scheme 133

1. Measure the free length of the tensioner spring. Replace the tensioner spring as necessary. Free Length 59.2 mm {2.331 in}

Scheme 134

Scheme 135

1. Remove the cylinder head cover.
2. Verify that the engine is in cold condition.
3. Measure the valve clearance. Turn the crankshaft clockwise so that the No.1 piston is at TDC of the compression stroke. Measure the valve clearance at A in the figure. Standard Valve Clearance [Engine Cold] IN: 0.18-0.24 mm {0.0071-0.0094 in} (0.21 +/- 0.03 mm {0.0083 +/- 0.0012 in} EX: 0.28-0.34 mm {0.0111-0.0133 in} (0.31 +/- 0.03 mm {0.0122 +/- 0.0012 in} If the valve clearance exceeds the standard, replace the adjustment shim. (Refer to «VALVE CLEARANCE ADJUSTMENT»(ref-182481-S25829294082005080800000) .) Turn the crankshaft 360° clockwise so that the No.4 piston is at TDC of the compression stroke. Measure the valve clearance at B in the figure. Standard Valve Clearance [Engine Cold] IN: 0.18-0.24 mm {0.0071-0.0094 in} (0.21 +/- 0.03 mm {0.0083 +/- 0.0012 in} EX: 0.28-0.34 mm {0.0111-0.0133 in} (0.31 +/- 0.03 mm {0.0122 +/- 0.0012 in} If the valve clearance exceeds the standard, replace the adjustment shim. (Refer to «VALVE CLEARANCE ADJUSTMENT»(ref-182481-S25829294082005080800000) .)
4. Install the cylinder head cover.