engine MAZDA MIATA 1997 Factory Manual PDF

Courtesy of MAZDA MOTORS CORP.
Removal & Installation (Protege)
1. Disconnect negative battery cable. Remove engine undercovers. Drain engine oil. Remove exhaust header
downpipe and brackets from front exhaust system. Remove oil pan retaining bolts.
2. DO NOT damage sealant contact surfaces. Remove oil pan by prying between oil pan and mounting
surface. On Protege, remove stiffener by prying between stiffener and cylinder block. On all models,
clean all sealant from oil pan, bolts, engine block and both sides of stiffener (Protege).
3. On Protege, apply oil resistant sealant to engine block and stiffener. Install stiffener. On all models, apply
sealant and install oil pan within 5 minutes of applying sealant. To complete installation, reverse removal
procedure. Tighten all bolts to specification. See TORQUE SPECIFICATIONS
. Fill engine with oil to
specification. See ENGINE LUBRICATION SYSTEM
under ENGINE OILING.
OVERHAUL
CYLINDER HEAD
Cylinder Head
Clean carbon and gasket material from all mating surfaces. Using a tap, clean cylinder head threads. Check
cylinder head warpage. If warpage exceeds specification, resurface head, but DO NOT exceed grinding limit.
See CYLINDER HEAD
under ENGINE SPECIFICATIONS. After resurfacing cylinder head, check cylinder
head height. Replace cylinder head if height is less than minimum specification.
Valve Springs
Ensure valve spring free length, out-of-square and compressed length are within specification. See VALVES &
VALVE SPRINGS under ENGINE SPECIFICATIONS. Replace valve spring if necessary.
Valve Stem Oil Seals
1. On Miata, use Installer Set (49-L012-0A0) to install valve seals. See Fig. 15 . Adjust installer dimension
"L" to seal depth of .720-.744" (18.3-18.9 mm). Using hand pressure ONLY, install seal until it contacts
cylinder head. Lightly oil valve seal lip.
2. On Protege, use Installer Set (49-L012-0A0) to install valve seals. See Fig. 15
. Adjust installer
dimension "L" to seal depth of .783" (19.9 mm). Using hand pressure, install seal until it contacts cylinder CAUTION: If reusing old oil pan bolts, remove old sealant from bolt threads.
Failure to remove old sealant may result in cracked block at bolt
holes.
NOTE: Intake and exhaust valve stem seals are different. Exhaust seals can be
identified by ridges molded into top of seal. Intake seals do not have identifying
ridges. Incorrect installation of valve stem seals will cause premature failure.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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head. Lightly oil valve seal lip.
Fig. 15: Installing Valve Guide Seals

Courtesy of MAZDA MOTORS CORP.
Valve Guides
1. Check valve stem-to-valve guide oil clearance. Ensure valve guide inside diameter is within specification.
See CYLINDER HEAD
under ENGINE SPECIFICATIONS.
2. Completely disassemble cylinder head. Gradually heat cylinder head in water to 194°F (94°C). Using
Valve Guide Remover (49-B012-005), drive valve guide out, working from combustion chamber side of
cylinder head. Repeat procedure if required, keeping cylinder head hot so aluminum head will not warp.
3. If required, install new circlip on guide. Using proper components of Valve Guide Installer (49-L012-
0A0), adjust installer guide depth (dimension "L") to specification using depth micrometer or caliper. See
VALVE GUIDE INSTALLED HEIGHT
. See Fig. 16 .
4. Insert guide into pre-adjusted installer and drive guide into cylinder head from camshaft side until guide
circlip, and/or installer contact cylinder head. Measure dimension "L" (guide installed height). See Fig.
16 or Fig. 15 . If installed height is not within specification, adjust or replace valve guide or cylinder head
as necessary. See VALVE GUIDE INSTALLED HEIGHT
.
NOTE: On Miata, use only NEW exhaust valve guides to replace intake or exhaust valve
guides.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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VALVE GUIDE INSTALLED HEIGHT
Fig. 16: Adjusting Valve Guide Installer & Installing Guide

Courtesy of MAZDA MOTORS CORP.
ApplicationIn. (mm)
Miata & Protege.720-.744 (18.30-18.90)

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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Fig. 17: Measuring Installed Valve & Guide Height
Courtesy of MAZDA MOTORS CORP.
Valve Seat
1. Service valve guide before valve seat. Valve seat replacement information is not available from
manufacturer. Inspect valve seat for roughness and damage. Check valve seat angle and seat width.
2. Measure seat contact width on valve and ensure seat contact position is in center of valve face. Service
seat if angle and width are not within specification. See CYLINDER HEAD
under ENGINE
SPECIFICATIONS. Measure valve installed height after servicing valve seat. See Fig. 17
. See VALVE
INSTALLED HEIGHT .
3. If valve installed height is within serviceable range, install adjusting shim on spring seat. If installed
height exceeds serviceable range, replace cylinder head.
VALVE INSTALLED HEIGHT
ApplicationIn. (mm)
Miata & Protege

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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Valves
Check valve face angle, head diameter, margin thickness and stem diameter. Service or replace valves if
measurements are not within specifications. See VALVES & VALVE SPRINGS
under ENGINE
SPECIFICATIONS.
Valve Seat Correction Angles
Measure seat contact width on valve. See VALVE SEAT. If seat width is not within specification or if valve
face does not contact center of valve seat, correct seat using a 70-degree grinding stone. After correcting seat,
lightly finish seat with 45-degree grinding stone.
VALVE TRAIN
Hydraulic Lash Adjusters
1. Remove camshaft cover. Check movement of each Hydraulic Lash Adjuster (HLA) by pushing
downward using hand pressure only. If HLA compresses, replace HLA. To remove HLA, remove
camshafts. See CAMSHAFT
under REMOVAL & INSTALLATION. Mark location of HLA before
removing from bore. Lift HLA from cylinder head.
2. Inspect HLA friction surfaces for wear and damage. Replace HLA if required. Coat HLA with engine oil
and install in original location. Ensure HLA moves smoothly in bore by using small magnet attached to
HLA.
CYLINDER BLOCK ASSEMBLY
Piston & Connecting Rod Assembly
1. Before removing rod cap from crankshaft, measure and record rod side play. See CONNECTING RODS
under ENGINE SPECIFICATIONS. Before removing connecting rods, measure and record connecting
rod bearing oil clearance. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS
under
ENGINE SPECIFICATIONS.
2. Before separating piston from connecting rod, mark piston in relation to connecting rod. Check
oscillation movement of piston and rod assembly (hold piston horizontally, lift rod and allow rod to drop
by its own weight). If pin binds in pin bore (rod does not drop), replace piston and/or pin as necessary.
3. To separate components, press piston pin out of piston and rod assembl
y, noting pressure required to
Normal1.772-1.791 (45.00-45.50)
Serviceable1.733-1.772 (45.60-46.50)
NOTE: If hydraulic lash adjusters are persistently noisy, check with manufacturer
for availability of modified adjusters.
NOTE: During disassembly, match mark components for reassembly reference.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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remove piston pin. If piston pin can be pressed out with less than 1100 lbs. (500 kg) of pressure, replace
piston and/or connecting rod.
4. Ensure piston pin diameter, piston fit and rod fit are within specification. See PISTONS, PINS &
RINGS under ENGINE SPECIFICATIONS. Using 1100-3300 lbs. (500-1500 kg) of pressure, install
piston pin through side of piston that has an "F" mark near pin bore. See Fig. 18
. Install piston and rod
assembly so "F" mark on side of piston is facing front of engine.
Fig. 18: Installing Piston & Connecting Rod Assembly

Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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Fitting Pistons
1. Ensure pistons are not scored or damaged. Measure piston diameter on piston skirt at 90-degree angle
from piston pin, .65" (16.5 mm) below lowest ring groove. See PISTONS, PINS & RINGS
under
ENGINE SPECIFICATIONS.
2. Check piston-to-cylinder wall clearance in 3 different vertical places of piston travel. If clearance is not
within specification, re-bore cylinders to fit oversize pistons. Using NEW piston rings, measure piston
ring side clearance around entire piston circumference. If clearance is not within specification, replace
piston. See PISTONS, PINS & RINGS
.
Piston Rings
1. If ring end gap and side clearance are not within specification, replace piston and/or rings as necessary.
See PISTONS, PINS & RINGS
under ENGINE SPECIFICATIONS.
2. Install oil ring spacer. Ensure ends DO NOT overlap. See Fig. 19
. Upper and lower rails are the same
and are interchangeable. In stall rails, ensuring rails are expanded by spacer tangs (oil rings when
assembled should rotate freely). Install rings No. 1 (top) and No. 2 (second) with "R" mark toward top of
piston. Ensure ring end gaps are properly positioned around piston. See Fig. 20
.
Fig. 19: Identifying Oil Rings
NOTE: Pistons and rings are available in .010" (.25 mm) and .020" (.50 mm) oversize.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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Courtesy of MAZDA MOTORS CORP.
Fig. 20: Identifying Piston Rings & Positioning Ring End Gaps

Courtesy of MAZDA MOTORS CORP.
Crankshaft & Main Bearings
1. Check crankshaft connecting rod journals for wear, out-of-round, taper and undersize. Machine or replace
crankshaft and/or bearings as necessary. See CRANKSHAFT, MAIN & CONNECTING ROD
BEARINGS under ENGINE SPECIFICATIONS.
2. Before removing main cap, measure and record crankshaft end play by prying crankshaft forward, then
rearward. Using Plastigage method, measure and record main bearing oil clearance. Remove crankshaft.
Measure and record each main journal diameter in 2 places. See CRANKSHAFT, MAIN &
CONNECTING ROD BEARINGS under ENGINE SPECIFICATIONS.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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3. Install main bearing caps with square mark facing front of engine. Tighten main bearing cap bolts in 2-3
step, working outward from center bearing. Tighten bolts to specification. See TORQUE
SPECIFICATIONS . Thrust Bearing - Install thrust bearing before installing crankshaft. Check
crankshaft end play with crankshaft bearings and caps installed, but without connecting rods attached to
crankshaft. DO NOT turn crankshaft until bearings are lubricated. If crankshaft end play exceeds
specification, grind crankshaft and replace thrust bearings with oversize thrust bearings, or replace
crankshaft and thrust bearings. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

under ENGINE SPECIFICATIONS.
Cylinder Block
Check cylinder bore out-of-round, taper, ridge and piston-to-cylinder bore clearance. Check head gasket surface
for warpage. If warpage is not within specification, machine or replace cylinder block as necessary. See
CYLINDER BLOCK
under ENGINE SPECIFICATIONS. Remove, clean and install oil jets for piston oil
spraying.
ENGINE OILING
ENGINE LUBRICATION SYSTEM
NOTE: See cross-sectional view of engine oil circuit. See Fig. 21
.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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Fig. 21: Cross-Sectional View Of Engine Oil Circuit
Courtesy of MAZDA MOTORS CORP.
Crankcase Capacity
See ENGINE OIL CRANKCASE CAPACITY .
Oil Pressure
With engine at operating temperature, oil pressure should be 15-28 psi (1.0-2.0 kg/cm2 ) at 1000 RPM, and 43-
57 psi(3.0-4.0 kg/cm
2 ) at 3000 RPM.
Oil Pressure Relief Valve
Pressure relief valve opening pressure is 50-64 psi (3.5-4.5 kg/cm2). Pressure relief valve is located in oil pump
body and is not adjustable.
ENGINE OIL CRANKCASE CAPACITY

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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