Semi-Finished 18° Cylinder Head

Your Price: $891.79

Suggested Retail:  $966.71

Semi-Finished 18° Cylinder Head

Product Details

The same superior Chevrolet Performance technology that professional NASCAR and NHRA racers have used to win races for decades is available for you to use in your racecar. The Chevrolet Performance Aluminum Racing Cylinder Heads are part of an extensive family of high-performance inline-valve heads, designed specifically for race-winning engines.

Chevrolet Performance Aluminum Racing Cylinder Heads start with castings designed with thicker decks and manifold flange areas. The combustion chambers are designed for competition and air passages are maximized for high-velocity airflow. These cylinder heads thrive on high compression and high rpm. Used in conjunction with optimized short-block, intake and valvetrain combos, these heads are part of an “instant-on” powerplant – the kind of engine that will put you in the winner’s circle.

Chevrolet Performance engineers dramatically altered the valve architecture to improve airflow and maximize efficiency. These aluminum racing cylinder heads are only available unported, so you must have them custom-ported to your specific requirements.

Aluminum Racing Head Technical Notes:
• Made of 355-T7 aluminum
• Extra-thick decks for angle milling or heavy flat milling
• Extra port material for professional porting
• Recommended for use with 4.000" to 4.155" cylinder bores
• Revised location angled spark plugs (14mm, 5/8" hex, 3/4" reach, gasketed plugs)
• Raised and revised location intake and exhaust ports for superior airflow above 0.600" valve lift
• Modified valve angles (not production 23°)
• Longer-than-stock valves required
• Designed for aftermarket shaft-mount rocker systems
• Perimeter-bolt-pattern-type valve covers required
• Specific 18°/15° intake manifold bolt patterns
• Recommended intake manifolds: P/N 24502481 or 24502653 (with valley plate P/N 24502654)
• Intake manifold gasket P/N 10185007

Semi-Finished 18° Cylinder Head
• Fully machined, semi-finished, no seats or guides
• Non-CNC ports and combustion chamber are “as-cast”
• 60cc “as-cast” combustion chambers
• Designed for up to 2.200"/1.625" valves
• 215cc “as-cast” intake ports
• .080" extra material on deck face, and .055" on intake face

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