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Inlet/Exhaust Valve Upgrades

G series engines came from the factory with 40mm (42.3mm some early models) inlet valves and 34mm exhaust valves, some early model cylinder heads have the nickname “big port head”. To ID which size valves are installed it’s best to measure before guessing! There is a lot of different revisions in the castings from the factory as some have provisions for EGR ports (exhaust side) and the mechanical fuel pump found on later TF/TG models.

$300-500~ 44/36mm upgrade

Common valve upgrades people have used are from the Mazda FE family engines, they can be installed fairly easy without too much drama. A engine machine shop should be able to do this work for around $200-300 AUD. This is a much better option than trying to hunt down a early big port head as they are becoming harder to find.


  • Head 44.00mm
  • Stem 8.00mm
  • Length 112.00mm


  • Head 36.00mm
  • Stem 8.00mm
  • Length 112.00mm

These valves can be found in the following models;

  • Mazda 626 FE 2.0L 1983-1987
  • Mazda B2200 F2G 2.2L 1988-1993
  • Kia Sportage 1995 FE 2.0L
  • Ford Telstar 1982-1987 2.0L FE

Part numbers: 9145233461, 021-3283, 021-3201, V2344, V2345

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