Valve Seat Replacement

WARNING: This page is about a different variant/trim than selected.

NOTE: When valve seat is removed, replace with an oversized [0.5 mm (0.020 in)] valve seat.

Bore out old seat until it collapses. Boring should not continue beyond the bottom face of the seat recess in the cylinder head. Set the machine depth stop to ensure this.
Ream cylinder head recess diameter for service valve seat.
Intake : 37.000 - 37.016 mm (1.4567 - 1.4573 in)

Exhaust : 32.000 - 32.016 mm (1.2598 - 1.2605 in)
- Be sure to ream in circles concentric to the valve guide center. This will enable the valve seat to fit correctly.
  
  Fig 1: Reaming Cylinder Head Recess Diameter For Service Valve Seat
  Courtesy of NISSAN MOTOR CO., U.S.A.
Heat cylinder head to 110° to 130°C (230° to 266°F) by soaking in heated oil.

Fig 2: Heating Cylinder Head
Courtesy of NISSAN MOTOR CO., U.S.A.
Use valve seats cooled well with dry ice. Force fit valve seat into cylinder head.
CAUTION: Avoid directly touching the cold valve seats.
Finish the seat to the specified dimensions using suitable tool.
CAUTION: When using valve seat cutter, firmly grip the cutter handle with both hands. Then, press on the contacting surface all around the circumference to cut in a single drive. Improper pressure on the cutter or cutting many different times may result in a defective valve seat.

Fig 3: Reaming Cylinder Head
Courtesy of NISSAN MOTOR CO., U.S.A.
Using compound, grind to adjust valve fitting.
Check again for normal contact.