Reinforced exhaust valves Toyota Celica Corolla 2ZZ-GE

Toyota engines covered

The 2ZZ-GE is Toyota's sporting 1.8 litre: four cylinders, 16 valves, twin overhead camshafts and the VVTL-i system that varies both valve timing and valve lift. It powers the Celica TS and the Corolla TS.

It has 8 exhaust valves, two per cylinder, part numbers 13715-88600, 13715-88601 then 13715-88602, with a stem of 5.445 to 5.470 mm. Switching to high lift keeps them working at high rpm for long periods, right in the flow of burnt gases.

SUPERTECH and FERREA reinforced exhaust valves

On a naturally aspirated engine like this one, the metal of an exhaust valve head reaches 760 to 870 °C; it goes past 1,000 °C as soon as a supercharger or turbo is added. About 75 % of the heat leaves through the seat and 20 % through the guide. An EV8 family steel keeps 550 MPa at 600 °C but only 300 MPa at 800 °C: the head can then distort, crack and stop bearing on its seat.

SUPERTECH offers two valves in black nitrided stainless steel, one of them in EV8 with a flat head face. FERREA makes its valves in Super Alloy, a nickel-based superalloy, with a single groove.

The +1 mm FERREA only enlarges the head, from 29 to 30 mm: each millimetre of head adds 10 to 12 cfm of flow, burnt gases leave faster and the chamber empties better. The 8 exhaust seats are then machined to that diameter.

Exhaust valve technical specifications

TEVN-1031 and TEVN-1031F: 29 mm head, 5.46 mm stem, 111.7 mm length, the second with a flat face. F2190P and F2191P: 29 and 30 mm head, 5.45 mm stem, 111.8 mm length.

Valve fitting

The FERREA valves have a single groove: they are fitted with the K10094 collets, intended for the 2ZZ-GE. With the SUPERTECH valves, check that the collets seat properly in the groove before releasing the springs.

At 29 mm, a simple recut of the seats is enough; the 30 mm valve requires the 8 exhaust seats of the head to be machined.

Keep the same size and the same brand on all 8 valves, and fit new exhaust valve stem seals, such as VS-T5.5E-8.

Technical guide

Our brands

	SUPERTECH Performance has been designing valves, springs and retainers for racing in California for more than thirty years. For the 2ZZ-GE it supplies two black nitrided stainless steel versions at standard size, one of them in EV8 with a flat face.
	FERREA has been producing racing valves since 1978, in Florida and Argentina. On the 2ZZ-GE its Super Alloy exhaust valve comes at standard size and +1 mm.

How to choose

Three versions are standard size; choose first by size, then by material:

When reinforced valves become necessary

• Adding a supercharger or a turbo
• Camshafts with more lift
• Track days at high rpm
• Cylinder head rebuild with burnt or distorted exhaust valves

Vehicle compatibility

OEM part number (exhaust valve): 13715-88600, 13715-88601, 13715-88602

Don't forget the inlet valves

The 2ZZ-GE inlet valves are best replaced in the same job, together with new valve stem seals.