# Camshaft journal diameter and out-of-round (NA6)

Canonical URL: https://miatatorque.com/spec/camshaft-journal-diameter-na6/

Applicability: NA 1990–1993 (B6) — Other years inferred from 1990 factory evidence.

Confidence: fsm

Diameter: 25.940–25.965 mm (1.0213–1.0222 in)
Out-of-round: 0.05 mm (0.002 in) max.

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": "camshaft-journal-diameter-na6",
  "name": "Camshaft journal diameter and out-of-round (NA6)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NA",
      "years": [
        1990,
        1993
      ],
      "engines": [
        "B6"
      ],
      "note": "Other years inferred from 1990 factory evidence."
    }
  ],
  "kind": "non-torque",
  "value_text": "Diameter: 25.940–25.965 mm (1.0213–1.0222 in)\nOut-of-round: 0.05 mm (0.002 in) max.",
  "procedure": {
    "notes": "Measure each journal in the X and Y directions at two axial positions."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1990",
      "page": "B–53 (PDF p. 80)",
      "as_printed": "Diameter: 25.940—25.965mm (1.0213—1.0222 in)\nOut-of-round: 0.05mm (0.002 in) max.",
      "verified_years": [
        1990,
        1990
      ],
      "document": {
        "id": "fsm-1990",
        "tier": 1,
        "title": "1990 Mazda MX-5 Miata Workshop Manual",
        "part_number": "1193-10-89C",
        "covers": [
          {
            "gen": "NA",
            "years": [
              1990,
              1990
            ],
            "engines": [
              "B6"
            ]
          }
        ],
        "url": "https://archive.org/details/1990-mazda-mx-5-miata-workshop-manual_202411"
      }
    }
  ],
  "jobs": [],
  "system": "engine",
  "component": "inventory-pass-2026-10",
  "componentName": "Service measurements and fasteners",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/camshaft-journal-diameter-na6/"
}
```