Semi-Machined Splayed-Valve Al. Cylinder Head

Product Details

SPLAYED-VALVE ALUMINUM RACE CYLINDER HEADS
Chevrolet Performance Splayed-Valve Aluminum Race Cylinder Heads are extremely aggressive, all-out competition heads and not intended for street use. Splayed valves point both intake and exhaust valves at the center of the cylinder bore. As the valves open, they move away from the edges of the bore. That allows maximum-size valves to be installed without increasing bore size. The result is dramatically increased airflow, compared to inlinevalve- design cylinder heads.

The castings have a 0.240-inch minimum port wall thickness, which leaves ample room for extensive custom porting. Intake valves are angled 16-degrees to the deck surface and splayed 4-degrees. Exhaust valve angles are 11-degrees with a 4-degree splay. Making more than 1,000 naturally aspirated horsepower with these cylinder heads is easily achievable.

Aluminum Splayed Valve Race Head Technical Notes:
• Made of 355-T7 aluminum
• No valve seats or guides provided
• Extra-thick decks for angle milling or heavy flat milling
• Extra port material (0.240") for professional porting
• Completely revised intake and exhaust ports provide ultimate airflow potential
• 45cc “as-cast” combustion chambers
• Modified valve angles (16° x 4° intake, and 11° x 4° exhaust)
• Designed for longer-than-stock 2.200" and 1.650" valves
• Valve spring pads accommodate 1.625" diameter springs
• Revised location angled spark plugs (14mm, 5/8" hex, 3/4" reach, gasketed plugs)
• Designed for aftermarket shaft-mount rocker systems
• Custom-fabricated intake manifold required
• P/N 10185042 intake manifold gasket required
• Valve cover gaskets P/N 10185043 required

Semi-Machined Splayed-Valve Aluminum Cylinder Head
• Main surfaces are machined; exhaust bolt pattern, valve guides and spark plug holes are machined
• Head bolt holes, dowel holes, intake bolt holes, pushrod holes are not machined
• Valve seats, spring seats and rocker stands are not machined
• 240cc “as-cast” intake ports
• 78cc “as-cast” exhaust ports
• 45cc “as-cast” combustion chambers
• Same casting as P/N 12480146

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