# Valve overall length (NA8)

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

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

Confidence: fsm

Length
Standard
IN: 101.89mm {4.0114 in}
EX: 101.99mm {4.0153 in}
Minimum
IN: 100.39mm {3.9524 in}
EX: 100.49mm {3.9563 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-length-na8",
  "name": "Valve overall length (NA8)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NA",
      "years": [
        1994,
        1997
      ],
      "engines": [
        "BP"
      ],
      "note": "Other years inferred from 1994 factory evidence."
    }
  ],
  "kind": "non-torque",
  "value_text": "Length\nStandard\nIN: 101.89mm {4.0114 in}\nEX: 101.99mm {4.0153 in}\nMinimum\nIN: 100.39mm {3.9524 in}\nEX: 100.49mm {3.9563 in}",
  "procedure": {
    "notes": "Measure each valve length; intake and exhaust differ."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1994",
      "page": "B–48 (PDF p. 85)",
      "as_printed": "Length\nStandard\nIN: 101.89mm {4.0114 in}\nEX: 101.99mm {4.0153 in}\nMinimum\nIN: 100.39mm {3.9524 in}\nEX: 100.49mm {3.9563 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-length-na8/"
}
```