Valve, Valve Guide Inspection

• If it is less than the specification, replace the valve.

Margin Thickness 

1. IN: 1.62 mm {0.0637 in} 
2. EX: 1.82 mm {0.0716 in} 
   Fig 1: Measuring Valve Head Margin Thickness

   Courtesy of MAZDA MOTORS CORP.

• If it is less than the specification, replace the valve.

Standard Length L 

1. IN: 102.99-103.79 mm {4.055-4.086 in} 
2. EX: 104.25-105.05 mm {4.105-4.135 in} 

Minimum Length L 

1. IN: 102.99 mm {4.055 in} 
2. EX: 104.25 mm {4.104 in} 
   Fig 2: Measuring Valve Length

   Courtesy of MAZDA MOTORS CORP.

• If it exceeds the specification, replace the valve.

Standard Diameter 

1. IN: 5.470-5.485 mm {0.2154-0.2159 in} 
2. EX: 5.465-5.480 mm {0.2152-0.2157 in} 

Minimum Diameter 

1. IN: 5.440 mm {0.2142 in} 
2. EX: 5.435 mm {0.2140 in} 
   Fig 3: Measuring Valve Stem Diameter

   Courtesy of MAZDA MOTORS CORP.

• If not as specified, replace the valve guide.

Standard Inner Diameter 

1. 5.509-5.539 mm {0.2169-0.2180 in} 
   Fig 4: Measuring Valve Inner Diameter

   Courtesy of MAZDA MOTORS CORP.

• If it exceeds the specification, replace the valve and/or the valve guide.

Standard Clearance 

1. IN: 0.024-0.069 mm {0.0009-0.0027 in} 
2. EX: 0.029-0.074 mm {0.0012-0.0029 in} 

Maximum Clearance 

1. 0.10 mm {0.004 in} 
   Fig 5: Measuring Valve Stem Clearance

   Courtesy of MAZDA MOTORS CORP.

• If not within the specified, replace the valve guide.

Standard Height 

1. 12.2-12.8 mm {0.481-0.503 in} 
   Fig 6: Measuring Valve Guide Protrusion Height

   Courtesy of MAZDA MOTORS CORP.