Showing specs for all NA & NB Miatas

Cylinder head gasket face distortion — maximum (NA6)

Distortion: 0.006 in (0.15 mm) max.Distortion: 0.15 mm (0.006 in) max.

Factory manualTaken from a Mazda factory workshop manual, with page citation.
Procedure

Measure in all six factory-specified directions. Before resurfacing inspect valve-seat sinking, manifold contact surfaces, camshaft oil clearance and end play.

Applies to
  • NA 1990–1993 (B6) — Other years inferred from 1990 factory evidence.
  • Verified in: 1990 Mazda MX-5 Miata Workshop Manual