AFR small port, high velocity 265cc cylinder heads are a cost effective choice compared to re-worked factory Big Block Chevrolet cylinder heads. The intake runners and exhaust ports are partially CNC machined, while the combustion chambers are offered with partial or full CNC machining with a bowl blend; this torque monster is capable of flowing 354 CFM at 0.650" lift.
Recommended for street, street/strip and towing applications with displacements up to 468 cubic inches operating at or below 6200 RPM.
|265cc Partial CNC Chamber BBC|
Material : A356 Aluminum
Intake Port Volume : 265cc
Intake Port Dimension : 2.030"H x 1.830"W x1/2 Radius
Intake Port :Location Stock
Exhaust Port Volume : 132cc
Exhaust Port Dimension : 1.770"H x 2.010" W
Exhaust Port Location : .375" Raised
Combustion Chamber Size : (Partial CNC) 109cc
Combustion Chamber Size : (Full CNC)112cc
Valve Cover Bolt : Pattern Perimeter Bolt
Valve : Angle 24°/4° Int, 15°/4° Exh
Valve Spring Pocket Diameter : 1.725" O.D
Max Valve Spring Pocket Machining : 1.750" O.D
Deck Thickness : .750"
Minimum Bore Diameter : 4.125"
Flat Mill : .006" per cc/ Maximum 102cc as cast or CNC chamber
Angle Mill : .009" per cc/ Maximum 97cc as cast or CNC chamber
Note:Angle mills might require a .120" Thick intake gasket.
Minimum Cross Sectional Area 2.640 sq. in.
Spark Plug Dimensions : 14mm x .750" w/Gasket Seat
** With some domed aftermarket pistons, it may be necessary to slightly clearance or modify the piston due to there more efficient heart shaped combustion chamber design. Most of the newer designed dome profiles will clear. AFR strongly recommends material be removed from the piston and not the cylinder head. Our combustion chamber shapes are very critical to flow and altering the cylinder head can adversely affect flow and power production. It is the customers responsibility to verify proper piston to head clearance.
*** Heads are designed for 3/8" pushrods. Larger pushrods will not fit without clearancing and is not recommended since some areas are very thin.
AFR recommends the use of .120" thick-wall pushrods.
AFR heads are available bare (without parts), call our tech line (714) 523-0530 for details.