Reinforced inlet valves TOYOTA Supra 7M-GE 7M-GTE

TOYOTA engines covered

The 7M is the 3.0-litre 24-valve twin-cam straight six of the Supra A70: 7M-GE naturally aspirated, 7M-GTE turbocharged, from 1986 to the early 1990s.

It has 12 inlet valves, original part number 13711-42020, worked by shim-adjusted tappets. More boost, a sharper camshaft or higher revs load them far more than the factory setting.

FERREA and SUPERTECH reinforced inlet valves

On the 7M, an inlet valve opens the way into the chamber on every cycle, presses back against its seat when the cam releases it and slides through its guide without pause. Its working temperature sits between 400 and 550 °C: across that range a common chromium-silicon grade drops from 500 MPa at 500 °C to 250 MPa at 600 °C, a 50 % loss of strength. On the 7M-GTE, raised boost pressure adds to these stresses.

Here FERREA provides Competition Plus valves: a stainless body with a chrome-plated stem, credited by the maker with a 20 % gain in high-temperature strength and in resistance to repeated loads, and with 25 % longer life at the seat. These valves suit both engine versions, 7M-GE and 7M-GTE. The SUPERTECH part, for the 7M-GTE only, is also made of stainless steel, with a 5.98 mm stem and a 98.1 mm length, very close to the FERREA dimensions. For collets, the FERREA valves take the maker's own K10037, the SUPERTECH valve the 6 mm KPR-6T-ST.

Three head diameters are available: 32 mm, the factory size, and 33 mm (+1 mm) from FERREA, 32.5 mm (+0.5 mm) from SUPERTECH. The wider the head, the larger the area offered to the fresh charge at the seat; filling improves and the straight six develops more power, provided every one of the 12 inlet seats is machined to match the selected valve. Stem and length stay the same whatever the size: 6 mm and 98.2 mm at FERREA.

Inlet valve technical specification

TIVN-1007-12: Supra 3.0 Turbo with the 7M-GTE engine only.

Fitting details

The 6 mm KPR-6T-ST collets suit the 7M-GTE; the FERREA K10037 are used on the 7M-GE and 7M-GTE.

The +0.5 and +1 mm sizes require all 12 inlet seats to be machined to the diameter of the chosen valve.

The 7M adjusts its valves with shims: after replacing the valves, check the clearance and adjust the shims.

Technical guide

The brands offered

	FERREA Racing Components settled in 1978 in Fort Lauderdale, on the east coast of Florida. Its valves start from a slug forged in one piece, which numerically controlled machining centres finish completely; you will see them in NASCAR and at the drag strip.
	Working out of San Jose, California, SUPERTECH Performance devotes itself, for more than thirty years now, to designing valves, springs and guides for motorsport. Every production lot is inspected with ultrasound, radiography and laser measurement before being shipped to engine tuners.

How to choose

On the 7M, two criteria decide: head diameter, matched to the seats, then brand, which depends on the engine version, naturally aspirated or turbo.

When reinforced valves become necessary

• Higher boost or a bigger turbo on the 7M-GTE
• Sharper cam profiles or harder springs
• Rev limiter moved up
• Cylinder head prepared for circuit racing or hill climb
• Tired Toyota valves or seats already recut

Compatible vehicles

OEM part number (inlet valve): 13711-42020

Related products

With the 7M head removed, this is the ideal moment to change its 12 exhaust valves too; our reinforced version is available through the link below: