fits model: Wrx, Sti, Std. make: Subaru. year: 2004.

( Brand: Manley Performance ), ( Manufacturer Part Number: 621000C-4 )
Introducing the 621000c-4 Manley 04 Subaru WRX STI EJ257 75mm De-stroked 99.5mm Standard 8.5 Dish Performance Cylinder Head, a high-performance upgrade for your Subaru WRX STI. This cylinder head is expertly designed and manufactured by Manley, a renowned name in the world of performance engine components.
The 621000c-4 Manley cylinder head is specifically engineered for the Subaru EJ257 engine, and its 75mm intake and 99.5mm standard bore size provide a generous increase in airflow and displacement compared to the stock 72mm intake and 92mm bore. This de-stroked design allows for increased combustion chamber volume, resulting in increased power and torque output.
The cylinder head features an 8.5-disc combustion chamber design, which provides excellent cylinder-to-cylinder symmetry and a more efficient flame front for improved engine performance. The 04 designation indicates that this cylinder head is specifically designed for the Subaru WRX STI, ensuring optimal fit and function.
Manley is known for its attention to detail and precision craftsmanship, and the 621000c-4 cylinder head is no exception. It is CNC-machined from high-quality aluminum alloy for superior strength and durability, and it features fully-machined valve seats for easy installation and superior sealing. The head also includes oversized valve guides and high-flow ports for improved airflow and power output.
Whether you're looking to upgrade your Subaru WRX STI for track use or simply want to increase its performance on the street, the 621000c-4 Manley 04 Subaru WRX STI EJ257 75mm De-stroked 99.5mm Standard 8.5 Dish Performance Cylinder Head is an excellent choice. Its high-quality construction, proven performance, and compatibility with the EJ257 engine make it a top choice for Subaru enthusiasts looking to take their vehicle to the next level.
Pros of buying a 621000C-4 Manley 04 Subaru WRX STI EJ257 75mm de-stroked 99.5mm std 8.5 dish performance pistons:1. Increased power and torque: De-stroking the engine can lead to an increase in power and torque, as it reduces the engine's compression ratio and allows for more air-fuel mixture to be burned in each cylinder stroke.
2. Improved engine durability: Manley pistons are known for their high-quality materials and manufacturing processes, which can lead to improved engine durability and longevity.
3. Enhanced engine performance: The 8.5-dishes pistons can help improve engine performance by reducing piston slap and engine noise, as well as increasing engine efficiency.
Cons of buying a 621000C-4 Manley 04 Subaru WRX STI EJ257 75mm de-stroked 99.5mm std 8.5 dish performance pistons:1. Higher cost: De-stroking the engine and installing performance pistons can be a costly upgrade, and it may not be cost-effective for all Subaru WRX STI owners.
2. Potential engine compatibility issues: De-stroking the engine and installing performance pistons may require other engine modifications, such as camshaft changes or intake and exhaust upgrades, to ensure proper engine operation and performance.
3. Potential engine power loss: If the engine is not properly tuned or upgraded to match the performance pistons, it may result in power loss or engine damage.
In conclusion, the 621000C-4 Manley 04 Subaru WRX STI EJ257 75mm de-stroked 99.5mm std 8.5 dish performance pistons can provide significant power and torque gains, as well as improved engine durability and performance. However, the higher cost and potential engine compatibility issues should be considered before making the purchase. If the upgrade is done properly, it can be a worthwhile investment for serious Subaru WRX STI enthusiasts looking to maximize their engine's potential. It is recommended to consult with a professional mechanic or engine builder to ensure the upgrade is done correctly and safely.
All final turning is performed in one texturing resulting complete squareness of rings to the cylinder wall. Levitt own, pa Manley 04 for Subaru Wrx Sti EJ257 75mm de-stroked 99.
Federal form-scan gauging validates ideal skirt indexing to pinhole and skirt-to-skirt polarity. Each design is lightweight yet robust enough to deliver long service life. 5:1 dish Manley pistons are machined of high strength 2618 material.
Precise pinhole machining results in an exact compression distance as well lock ring groove spacing, size, and concentrate. Proprietary multi-step top ring groove machining process assures optimum control of the grooves size, geometry, flatness, and finish. Forging alloy for maximum high temperature strength and fatigue resistance.
5mm Std bore 8. Value - added features such as a pressure balance groove included in all series. Perfect ring groove to skirt squareness is achieved through our unique one texturing manufacturing method that assures maximum horsepower.