# Valve guide installed projection (NA8)

Canonical URL: https://miatatorque.com/spec/valve-guide-height-na8/

Applicability: NA 1994–1997 (BP) — Other years inferred from 1994 factory evidence.

Confidence: fsm

Height: 18.3—18.9mm {0.721—0.744 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-guide-height-na8",
  "name": "Valve guide installed projection (NA8)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NA",
      "years": [
        1994,
        1997
      ],
      "engines": [
        "BP"
      ],
      "note": "Other years inferred from 1994 factory evidence."
    }
  ],
  "kind": "non-torque",
  "value_text": "Height: 18.3—18.9mm {0.721—0.744 in}",
  "procedure": {
    "notes": "Dimension A is installed guide projection from the head reference surface along the guide axis. Verify after installation. Factory installer depth L uses the same range; use correct SST. Source states exhaust guide may replace intake guide despite original differences."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1994",
      "page": "B–49 (PDF p. 86)",
      "as_printed": "Height: 18.3—18.9mm {0.721—0.744 in}",
      "verified_years": [
        1994,
        1994
      ],
      "document": {
        "id": "fsm-1994",
        "tier": 1,
        "title": "1994 Mazda MX-5 Miata Workshop Manual",
        "covers": [
          {
            "gen": "NA",
            "years": [
              1994,
              1997
            ],
            "engines": [
              "BP"
            ]
          }
        ],
        "note": "Mazda's base manual for 1994–97; later model years got supplements, which we haven't checked yet."
      }
    }
  ],
  "jobs": [],
  "system": "engine",
  "component": "inventory-pass-2026-10",
  "componentName": "Service measurements and fasteners",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/valve-guide-height-na8/"
}
```