# Valve stem protrusion for seat sinking inspection (Mazdaspeed)

Canonical URL: https://miatatorque.com/spec/valve-stem-protrusion-msm/

Applicability: NB 2004–2005 (BP-Z3-TURBO) — 2004 factory turbo-engine evidence; 2005 inferred within MSM family.

Confidence: fsm

Standard dimension L
IN: 45.0 mm {1.772 in}
EX: 45.0 mm {1.772 in}
Maximum dimension L
IN: 45.6 mm {1.795 in}
EX: 45.6 mm {1.795 in}

Always confirm against your factory manual. Match every restriction and follow all stages and procedure notes. Disputed claims must not be automatically resolved. The complete record below preserves every printed unit, source claim and procedure.

```json
{
  "id": "valve-stem-protrusion-msm",
  "name": "Valve stem protrusion for seat sinking inspection (Mazdaspeed)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NB",
      "years": [
        2004,
        2005
      ],
      "engines": [
        "BP-Z3-TURBO"
      ],
      "note": "2004 factory turbo-engine evidence; 2005 inferred within MSM family."
    }
  ],
  "kind": "non-torque",
  "value_text": "Standard dimension L\nIN: 45.0 mm {1.772 in}\nEX: 45.0 mm {1.772 in}\nMaximum dimension L\nIN: 45.6 mm {1.795 in}\nEX: 45.6 mm {1.795 in}",
  "procedure": {
    "notes": "Seat-sinking inspection dimension L; replace the cylinder head as necessary. This is not the guide protrusion dimension."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "workshop-bp-turbo-2004",
      "page": "01–10–20 (PDF p. 32)",
      "as_printed": "Standard dimension L\nIN: 45.0 mm {1.772 in}\nEX: 45.0 mm {1.772 in}\nMaximum dimension L\nIN: 45.6 mm {1.795 in}\nEX: 45.6 mm {1.795 in}",
      "verified_years": [
        2004,
        2004
      ],
      "document": {
        "id": "workshop-bp-turbo-2004",
        "tier": 1,
        "title": "2004 Mazda Engine Workshop Manual BP (1.8L), normally aspirated and turbo",
        "part_number": "9999-95-EWBP-04",
        "covers": [
          {
            "gen": "NB",
            "years": [
              2004,
              2004
            ],
            "engines": [
              "BP-Z3-TURBO"
            ],
            "trans": [
              "6MT"
            ]
          }
        ]
      }
    }
  ],
  "jobs": [],
  "system": "engine",
  "component": "inventory-pass-2026-10",
  "componentName": "Service measurements and fasteners",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/valve-stem-protrusion-msm/"
}
```