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
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 27 © 2005 Mitchell Repair Information Company, LLC.
