Speedmaster . PCE281.2039

CNC Aluminum Cylinder HeadBig Block Chevy 454 w/Solid Roller CamAssembled Head125cc Combustion Chamber360cc Intake RunnerIncludes Valves & SpringsSet of 2 Special Note: Camshaft and Lifters Not Included Assembly Specifications<br/><br/> Max Lift: .650<br/> Coil Bind: .925<br/> Intake Install: 275lbs @ 2.1<br/> Exhaust Install: 275lbs @ 2.1<br/> Closed Sear Pressure: 210lbs<br/> Open Seat Pressure: 450lbs<br><br/><br/> As with all Speedmaster cylinder heads, our Big Block Chevrolet heads are Gravity Die Cast . This casting process creates a much more uniform and robust cylinder head. With the increasingly large displacements becoming common, the need for more airflow is necessary. If you are looking to build a 400-500+hp engine, give our PCE281.1489 heads a try. They offer a smaller cross - section to increase the incoming air s velocity, resulting in great driveability, power and economy. On engines over 500hp, use the rectangle port PCE281.1488 heads. The mid-size cross section works well on engines under 540cu.in and under 7000RPM. If you are working on a larger, or higher RPM engine, step up to the CNC ported PCE281.1511 heads. The added volume of the PCE281.

Brand: Speedmaster <br> Part Number: PCE281.2039 <br> Part Type: Cylinder Heads <br> <br> Cylinder Head Style: Assembled <br> Cylinder Head Material: Aluminum <br> Cylinder Head Finish: Natural <br> Combustion Chamber Volume (cc): 125 cc <br> CNC-Machined Combustion Chamber: Yes <br> Intake Runner Volume (cc): 360 cc <br> Exhaust Runner Volume (cc): n/a <br> CNC-Machined Intake Runner: Yes <br> CNC-Machined Exhaust Runner: Yes <br> Intake Port Shape: Rectangular <br> Intake Port Location: Standard <br> Exhaust Port Shape: Rectangular <br> Exhaust Port Location: Raised <br> Spark Plug Style: Angle <br> Comp. Valve Job: No <br> Intake Valves Included: Yes <br> Intake Valve Diameter (in): 2.250 in. <br> Exhaust Valves Included: Yes <br> Exhaust Valve Diameter (in): 1.880 in.Ê<br> Valve Springs Included: Yes <br> Maximum Valve Lift (in): 0.650 in. <br> Outside Diameter of Outer Spring (in): 1.550 in. <br> Damper Spring Included: Yes <br> Number of Springs Per Valve: Dual <br> Retainers Included: Yes <br> Retainer Material: Chromoly steel <br> Locks Included: Yes <br> Lock Style: 10 degree <br> Valve Stem Seals Included: Yes <br> Valve Stem Seal Style: Positive stop <br> Rocker Arm Studs Included: NoÊ<br> Rocker Arms Included: NoÊ<br> Rocker Arm Nuts Included: NoÊ<br> Guideplates Included: NoÊ<br> Valve Cover Mounting Style: Center & Perimeter Bolt <br> Accessory Bolt Holes Drilled: YesÊ<br> Intake Valve Angle: 24 deg. <br> Exhaust Valve Angle: 15 deg. <br> Valve Guides Included: YesÊ<br> Valve Guide Material: BronzeÊ<br> Valve Seats Machined: Yes <br> Valve Seat Machine Style: 3-angle <br> Valve Seat Material: Ductile ironÊ<br> Steam Holes Drilled: No <br> Oiling Style: Through pushrodÊ<br> Machined for O-Ring: NoÊ<br> Heat Crossover: No <br> Quantity: Sold as a pair. <br> Calculator Compression Calculator <br>