SUPERTECH bronze exhaust valve guides Subaru BRZ Toyota GT86 FA20 4U-GSE

The Subaru and Toyota engines concerned

This set concerns the 2.0 litre four-cylinder flat engine that Subaru calls FA20 (FA20D, FA20E, FA20F) and Toyota 4U-GSE. It sits under the bonnet of the Subaru BRZ, WRX, Forester XT, Levorg, Outback and Legacy, and of the Toyota GT86.

The exhaust guides in this set carry SUPERTECH reference GDE-TFRS55-E-8: 5.5 mm bore, 10.05 mm outside diameter, 37 mm length. The lot of 8 equips the eight exhaust valves of the engine; the inlet guides are covered by a neighbouring page. The original Subaru guide is 13213-AA191 on the FA20F.

SUPERTECH exhaust valve guides for Subaru and Toyota FA20

On the exhaust side the guide faces the burning gases that lick the stem: it holds the valve in line, sends that heat off to the head and bears the stem seal. When the bore wears the valve starts to rattle, its seating deteriorates, compression drops and bluish smoke betrays burnt oil. Fitting new seals alone does not cure a worn bore.

SUPERTECH machines these guides in manganese bronze, a metal rich in copper which, the brand says, transmits heat much faster than the sintered standard. They usually go with reinforced exhaust valves, which work harder. A lot of 8 is enough for the whole exhaust side of the engine.

Valve guide technical specifications

Valve guide installation

Technical guide

On the exhaust side, reinforced valves are offered as well:

Our brand

SUPERTECH has been based in San Jose for over three decades. Its competition valvetrain parts are checked by ultrasound, by radiography and by laser measurement.

Manganese bronze

Manganese bronze is copper alloyed with zinc, iron, aluminium and manganese. The recipe gives a hard metal with high mechanical strength that rubs for a long time without wearing a groove and resists corrosion, handy for a guide exposed to hot gases.

When valve guides must be replaced

• Blue smoke under acceleration, oil used with no leak
• Reinforced exhaust valves for a hard-worked engine
• Flat engine tuned for competition or boosted
• Heads reworked in an overhaul

Vehicle compatibility

OEM reference (exhaust valve guide): 13213-AA191 (Subaru FA20F)

Remember the inlet guides and the valve stem seals

Once the guides are changed, fit new stem seals: better to do it during that same job.