Reinforced exhaust valves Toyota 2RZ-FE 3RZ-FE

Toyota engines covered

The 2RZ-FE (2.4 litre) and 3RZ-FE (2.7 litre) are Toyota's twin-cam 16-valve four-cylinders of the Tacoma, Hilux, 4Runner, T100 and Land Cruiser 90 and Prado.

They have 8 exhaust valves, two per cylinder. Toyota lists them as 13715-76030 and 13715-75050, with a 30.5 mm head on the 13715-76030, a 5.965 to 5.980 mm stem and a 103.60 mm length. The reinforced valves have a 5.965 mm stem and a 103.6 mm length, with a 30.5 mm head at standard size, 31.5 mm at +1 mm or 32.5 mm at +2 mm.

SUPERTECH reinforced exhaust valves

On these often heavily loaded engines, the head of an exhaust valve reaches 760 to 870 °C naturally aspirated and passes 1,000 °C with a supercharger or a turbo. The seat removes about 75 % of that heat, the guide about 20 %. EV8 family steel, used as the reference for the original, goes from 550 MPa at 600 °C to 300 MPa at 800 °C: overheating, fatigue, a distorted head and then a leaking seat.

The TEVN-1045-8 is EV16 black nitrided stainless steel, a treatment that hardens the surface and limits stem wear. The TEVI-1047-8 and TEVI-1048-8 are Inconel, a nickel-based superalloy that keeps 860 MPa at 732 °C and 554 MPa at 816 °C, about 85 % more than EV8 steel around 800 °C: the choice for forced induction.

At +1 mm (31.5 mm) or +2 mm (32.5 mm), the larger head lets burnt gases out faster and empties the cylinder better, provided the 8 seats are machined to that diameter.

Exhaust valve technical specifications

The TEVN-1045-8 is made of EV16 stainless steel with a 4.5 mm tip; the TEVI-1047-8 and TEVI-1048-8 are made of Inconel.

Valve fitting

Before fitting, check that the collets suit the groove of the SUPERTECH valves.

The TEVN-1045-8 fits seats reground at standard size; the TEVI-1047-8 and TEVI-1048-8 need seats machined to 31.5 or 32.5 mm.

The three sets share the same 5.965 mm stem, the same 103.6 mm length and the same 4.5 mm tip.

Technical guide

Our brand

SUPERTECH Performance, a Californian maker of competition valves for more than thirty years, offers the 2RZ-FE and 3RZ-FE a black nitrided stainless steel exhaust valve at standard size and two Inconel versions at +1 and +2 mm.

How to choose

Size and material go together on these three part numbers:

When reinforced valves become necessary

• Supercharger or turbo conversion (Inconel version recommended)
• More aggressive camshafts
• Heavy off-road use or towing
• Cylinder head rebuild with worn exhaust valves

Vehicle compatibility

OEM part number (exhaust valve): 13715-76030 ; 13715-75050

Don't forget the inlet valves

An open 2RZ-FE or 3RZ-FE cylinder head is also the time to replace the inlet valves and the valve stem seals.