SUPERTECH intake valve stem seals Honda B18A B18B B20 D16A1 D16A9 ZC

Honda engines concerned

This set fits the 6.6 mm stem intake valves of Honda's non-VTEC 16-valve four-cylinders: the D16A9 and D16A1 of the Civic, CRX and Concerto, the ZC of Japanese-market Integra and Civic models, the B18A and B18B of the Integra, Civic, Domani and Orthia, plus the B20B and B20Z of the CR-V, Stepwgn and S-MX. The Acura Integra 1.6 and 1.8 are covered as well.

The head carries 8 intake valves, two per cylinder. The original seal caps the guide and only lets through the oil the stem needs; Honda lists it as two parts, 12210-PT2-004 (seal A) and 12211-PT2-004 (seal B), 8 of each per head.

SUPERTECH inlet valve stem seals

Sitting between stem and guide, the seal meters the oil: it stops most of it but leaves a thin film to ease the rubbing, otherwise stem and guide wear quickly. Once aged or baked by heat it holds nothing back: the engine starts drinking oil, puffs blue when first started or after a long wait at idle and leaves valves and plugs sooty.

SUPERTECH moulds its intake seals in polyacrylate (ACM), a quality rubber, for a 12 mm outside diameter guide and a 6.6 mm stem. The 8 pieces take care of every intake valve in one head; for the hotter exhaust the brand supplies a high-temperature compound as a separate set.

Stem seal technical specifications

Stem seal installation

Technical guide

The brand offered

Based in San Jose, south of San Francisco Bay, SUPERTECH has designed racing valves, springs, guides and stem seals for over 30 years. Every part is inspected by ultrasound, X-ray and laser before renowned engine builders prove it in service.

Inlet or exhaust?

Same dimensions for both seals, different material: VS-H6.6-I polyacrylate (ACM) on the intake, VS-H6.6-E Viton (FKM) on the exhaust, where the valves run hottest. According to SUPERTECH, polyacrylate copes with up to 177 °C (350 °F) and Viton with 204 °C (400 °F) continuous. Every 16-valve Honda head takes 8 seals on each side, so two sets for a full job.

When valve stem seals must be replaced

• Falling oil level, blue smoke at start-up or idle
• Valves removed, head being rebuilt
• Valve guides being replaced
• Fitting of uprated springs or valves

Vehicle compatibility

Honda

Acura

OEM part number (Honda B18A, B18B, B20, D16A9 stem seals): 12210-PT2-004 (seal A) and 12211-PT2-004 (seal B), 8 of each; Arai equivalents 12210-PT2-003 and 12211-PT2-003. D16A9 from 1988 to 1993 and 1991 B18A2: 12210-PM7-004 and 12211-PH7-004 (Arai 12210-PM7-003 and 12211-PH7-003).

Remember the exhaust valve stem seals

Use the head teardown to renew the exhaust seals too, as they wear just as fast. SUPERTECH supplies them for these engines: