SUPERTECH exhaust valve stem seals Toyota Lotus 1ZZ 2ZZ 2AZ 2TR 1AR

Toyota engines concerned

These seals equip the 5.5 mm stem exhaust valves of Toyota 16-valve four-cylinders: 1ZZ-FE (Corolla, Avensis, Celica, MR2, RAV 4), 2ZZ-GE (Celica, Corolla, Lotus Elise, Exige and 2-Eleven), 2AZ-FE (Camry, RAV 4, Previa, Scion tC, Lexus ES), 2TR-FE (Hilux, Tacoma, Land Cruiser Prado) and 1AR-FE (Highlander, Venza, Sienna, Lexus RX).

The exhaust side has 8 valves per head, two per cylinder. Fitted on the guide, the original seal stops the top-end oil while still lubricating the stem; Toyota offers it under several numbers: 90913-02101, 90913-02111 or 90913-02112 on the 1ZZ-FE, 2AZ-FE and 2TR-FE, 90913-02114 and 90913-02115 on the 2ZZ-GE.

SUPERTECH exhaust valve stem seals

On the exhaust, the stem seal soaks up the heat of the valve that lets the burnt gases out. Once it hardens, cracks or sags, oil runs along the stem into the chamber and goes up in smoke: frequent top-ups, blue smoke, carbon on the valve heads and in the manifold. A trace of oil must still get through, otherwise stem and guide deteriorate.

SUPERTECH keeps Viton (FKM) for the exhaust, a high-temperature compound chosen to age well beside hot valves; according to the brand it is made for high temperatures and holds 204 °C (400 °F) continuous. The seal fits a 5.5 mm stem and a 10.3 mm outside diameter guide. These 8 pieces cover the exhaust of a complete head; the intake uses polyacrylate (ACM), delivered in another set.

Stem seal technical specifications

Stem seal installation

Technical guide

The brand offered

From its base in San Jose, California, the SUPERTECH team has designed racing stem seals, guides, springs and valves for more than 30 years. New parts are first computed with finite elements, then proven in real conditions by tuners before going on sale.

Why two different materials?

The two seals are dimensionally the same, although the exhaust valve operates at a much higher temperature. SUPERTECH therefore fits the more resistant VS-T5.5-E Viton (FKM) there and trusts the intake to VS-T5.5-I polyacrylate (ACM). These Toyota heads need 8 of each.

When valve stem seals must be replaced

• Frequent oil top-ups, blue smoke
• Valves out or head machined
• New valve guides to be fitted
• Uprated valves or springs being fitted

Vehicle compatibility

Toyota

Lexus

Scion

Lotus

OEM part number (Toyota 1ZZ-FE, 2AZ-FE, 2TR-FE, 2ZZ-GE stem seals): 90913-02101, 90913-02111 and 90913-02112 depending on version and period (1ZZ-FE, 2AZ-FE, 2TR-FE), with 90080-31043 and 90080-31046; 2ZZ-GE: 90913-02114 and 90913-02115.

Remember the inlet valve stem seals

Sharing this head, the intake seals wear just as fast: swap them in this teardown. SUPERTECH stocks them for these engines: