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GSC P-D 3057-12 Manganese Bronze Exhaust Valve Guides for Porsche 996/997 Turbo - Set of 12
The GSC P-D 3057-12 provides a complete set of 12 standard-size manganese bronze exhaust valve guides for Porsche 996 and 997 Turbo engines. Exhaust valve guides operate under extreme heat and load conditions, making material selection critical for durability. Manganese bronze conducts heat more efficiently than cast iron and resists wear at elevated temperatures, helping maintain precise valve alignment and oil control over extended service intervals. The 3057-12 is the go-to choice for Porsche engine rebuilders seeking a direct OEM-dimension replacement with improved long-term performance characteristics.
Features and Benefits
- Manganese bronze alloy provides superior heat resistance for exhaust guide duty
- Standard OD fits the factory bore without additional machine work in most applications
- Set of 12 covers all exhaust valve positions in the Porsche 996/997 Turbo flat-six
- Precision-machined for consistent wall thickness and guide bore geometry
- Improved wear characteristics extend rebuild intervals versus OEM cast iron
- Trusted by professional Porsche engine builders worldwide
- Available in standard and oversize OD options from GSC P-D
Fitment
| Year | Make | Model | Engine |
|---|---|---|---|
| 2001 | Porsche | 911 Turbo (996) | 3.6L Twin-Turbo H6 |
| 2002 | Porsche | 911 Turbo (996) | 3.6L Twin-Turbo H6 |
| 2003 | Porsche | 911 Turbo (996) | 3.6L Twin-Turbo H6 |
| 2004 | Porsche | 911 Turbo (996) | 3.6L Twin-Turbo H6 |
| 2005 | Porsche | 911 Turbo (997) | 3.6L Twin-Turbo H6 |
| 2006 | Porsche | 911 Turbo (997) | 3.6L Twin-Turbo H6 |
| 2007 | Porsche | 911 Turbo (997) | 3.6L Twin-Turbo H6 |
| 2008 | Porsche | 911 Turbo (997) | 3.8L Twin-Turbo H6 |
| 2009 | Porsche | 911 Turbo (997) | 3.8L Twin-Turbo H6 |
| 2010 | Porsche | 911 Turbo (997) | 3.8L Twin-Turbo H6 |
Specifications
| Specification | Detail |
|---|---|
| Part Number | 3057-12 |
| Brand | GSC Power-Division |
| Material | Manganese Bronze |
| Style | Standard OD |
| Quantity | Set of 12 (full exhaust set) |
| Application | Porsche 996 / 997 Turbo |
| Warranty | Manufacturer limited warranty |
What's Included
- 12 x Manganese Bronze Exhaust Valve Guides (GSC P-D 3057-12)
Frequently Asked Questions
What engines does the GSC P-D 3057-12 fit?
These exhaust valve guides are designed for the Porsche 996 and 997 Turbo flat-six engines, including both the 3.6L and 3.8L twin-turbocharged variants.
Why are manganese bronze guides preferred for exhaust applications?
Exhaust guides run significantly hotter than intake guides. Manganese bronze has better thermal conductivity and wear resistance at high temperatures compared to cast iron, making it the preferred upgrade material for performance and reliability rebuilds.
Are these standard size or oversized?
The 3057-12 is standard outside diameter. GSC also produces oversize OD variants for parent bores that have been worn or previously machined.
Do I need to replace intake and exhaust guides at the same time?
Best practice is to replace both sets during a full head rebuild. GSC also offers the Porsche 996/997 Turbo intake guide set to complement the 3057-12.
Can the GSC P-D 3057-12 be used on a built or heavily modified Turbo engine?
Yes. The upgraded material is well-suited for high-boost, high-RPM applications where heat and wear on exhaust components are elevated.
How many exhaust valves does the Porsche 996/997 Turbo engine have?
The flat-six has 12 exhaust valves total, two per cylinder, so this set covers all positions.
Does installation require machine shop work?
Yes. Valve guides must be pressed out and pressed in using proper tooling and an arbor press, then reamed to the correct ID for the valve stems being used.
Is GSC P-D a reputable source for Porsche engine components?
Yes. GSC Power-Division is well-regarded in the performance engine building community, with specific application-engineered parts for European and Japanese performance platforms.
Installation Notes
- Remove the cylinder head from the engine following Porsche factory procedures.
- Press out the old exhaust valve guides using a proper piloted driver and arbor press.
- Clean and inspect the guide parent bores for wear or damage.
- Chill the new 3057-12 guides and/or gently heat the head to ease installation.
- Press new guides to the correct depth per Porsche specification.
- Ream each guide to the correct inside diameter for the valve stems being used.
- Complete valve seat reconditioning and reassemble the cylinder head.
- Torque the head to factory specifications on reinstallation.
CALIFORNIA PROPOSITION 65 WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
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