Supertech Manganese Bronze Intake Valve Guides – Toyota FA20D (FR-S / BRZ / 86) | 5.5mm Stem | Set of 8 | GDE-TFRS55-I-8

Supertech manganese bronze intake valve guides for the Toyota FA20D flat-four — the engine used in the Scion FR-S, Toyota 86 (ZN6), and Subaru BRZ (ZC6). 5.5mm stem diameter to match FA20D intake valve stem specification. Set of 8 — a complete intake guide set for the FA20D’s four cylinders with two intake valves per cylinder. Intake guides only — exhaust guides sold separately. The correct upgrade over factory cast iron guides for any FA20D head rebuild targeting performance use.

Why Manganese Bronze for the FA20D

The FA20D factory valve guides are cast iron — adequate for OEM use but not the optimal material for a performance head rebuild. Cast iron has relatively poor thermal conductivity and limited lubricity — heat generated at the valve stem/guide interface dissipates slowly, and the valve stem runs in a guide material that offers minimal self-lubrication.

Manganese bronze (C63000) addresses both limitations. As an alloy, it has significantly better thermal conductivity than cast iron — heat generated at the valve stem transfers out through the guide into the head more efficiently, keeping valve stem and guide temperatures lower during sustained high-RPM operation. Manganese bronze also has inherent lubricity — the alloy’s structure provides a degree of self-lubrication at the stem/guide interface, reducing wear under the marginal lubrication conditions that exist at the top of the valve guide. For an FA20D that will see sustained high-RPM use on track or in a high-output build, manganese bronze guides are the standard upgrade specification for any serious head rebuild.

Key Features

• Manganese Bronze (C63000): Premium aftermarket valve guide material — better thermal conductivity and inherent lubricity compared to factory cast iron. Standard specification for performance head rebuilds on the FA20D and other high-revving four-cylinder engines
• 5.5mm Stem Diameter: Matches the FA20D intake valve stem specification — confirm your specific intake valve stem diameter before ordering. Do not assume stem diameter without measurement if using aftermarket valves
• Intake Only: This set covers the intake valve guides only. The FA20D uses two intake and two exhaust valves per cylinder — 8 intake guides total for the complete engine. Exhaust guides are a separate part number — confirm whether your head rebuild requires intake only, exhaust only, or both
• Set of 8: Complete intake guide set for the 4-cylinder FA20D — sufficient to replace all intake guides in a single head rebuild
• Supertech Engineering: Supertech is a respected performance engine components manufacturer with a strong presence in the FR-S/BRZ/86 and broader Japanese performance engine builder community

Installation Notes

Valve guide replacement requires a heated cylinder head and precision installation tooling — guides are pressed into the head with an interference fit. This is a machine shop operation, not a hand-tool job. Key installation requirements:

• Existing guides must be pressed or driven out of the heated head
• New guides are pressed in with the head at temperature — typically heated to 150–200°C to expand the guide bores for installation
• After installation, guides must be reamed to final stem clearance specification — Supertech’s recommended stem-to-guide clearance should be confirmed from their product documentation
• Valve seats must be re-cut after guide installation to ensure concentricity between the new guide centreline and the seat
• This work must be performed by a qualified engine machinist with appropriate valve guide installation and reaming equipment

Fitment

• Scion FR-S / Toyota 86 ZN6 (2012–2021) — FA20D
• Subaru BRZ ZC6 (2012–2021) — FA20D

FA20D only — not for the FA20E (GR86 / BRZ Gen 2, 2022+) or FA20 non-D variants. Confirm engine code before ordering. Confirm intake valve stem diameter against your specific valves before ordering — 5.5mm is the factory FA20D intake stem specification, but aftermarket valves may vary.

Intake guides only — exhaust guides sold separately. Valve guide replacement is a machine shop operation requiring a heated head, press, and reaming equipment — professional installation by a qualified engine machinist is required. Valve seats must be re-cut after guide installation for concentricity. Confirm stem-to-guide clearance specification from Supertech’s product documentation before reaming. Not compatible with FA20E (2022+ GR86/BRZ Gen 2).

Specifications

• Brand: Supertech
• Part Number: GDE-TFRS55-I-8
• Material: Manganese Bronze (C63000)
• Type: Intake valve guides
• Stem Diameter: 5.5mm
• Quantity: 8 (complete FA20D intake set)
• Engine: Toyota FA20D
• Application: Scion FR-S / Toyota 86 ZN6 / Subaru BRZ ZC6 (2012–2021)
• Weight: 0.32 lbs