Pontiac 389 455 215cc 72cc Ram Air IV Hyd-R Complete Cylinder Heads + FREE Intake
|Part Type:||Cylinder Heads|
|Cylinder Head Style:||Assembled|
|Cylinder Head Material:||Aluminum|
|Cylinder Head Finish:||Natural|
|Combustion Chamber Volume (cc):||72 cc|
|CNC-Machined Combustion Chamber:||Yes|
|Intake Runner Volume (cc):||215 cc|
|Exhaust Runner Volume (cc):||175 cc|
|CNC-Machined Intake Runner:||No|
|CNC-Machined Exhaust Runner:||No|
|Intake Port Shape:||Ram Air IV|
|Intake Port Location:||Standard|
|Exhaust Port Shape:||Ram Air IV|
|Exhaust Port Location:||Standard|
|Spark Plug Style:||Straight|
|Comp. Valve Job:||Yes|
|Intake Valves Included:||Yes|
|Intake Valve Diameter (in):||2.110 in.|
|Exhaust Valves Included:||Yes|
|Exhaust Valve Diameter (in):||1.660 in.|
|Valve Springs Included:||Yes|
|Maximum Valve Lift (in):||0.580 in.|
|Outside Diameter of Outer Spring (in):||1.450 in.|
|Damper Spring Included:||Yes|
|Number of Springs Per Valve:||Dual|
|Retainer Material:||Chromeoly steel|
|Lock Style:||10 degree|
|Valve Stem Seals Included:||Yes|
|Valve Stem Seal Style:||Positive stop|
|Rocker Arm Studs Included:||No|
|Rocker Arms Included:||No|
|Rocker Arm Nuts Included:||No|
|Valve Cover Mounting Style:||Center & Perimeter Bolt|
|Accessory Bolt Holes Drilled:||Yes|
|Intake Valve Angle:||14 deg.|
|Exhaust Valve Angle:||14 deg.|
|Valve Guides Included:||Yes|
|Valve Guide Material:||Bronze|
|Valve Seats Machined:||Yes|
|Valve Seat Machine Style:||3-angle|
|Valve Seat Material:||Ductile iron|
|Steam Holes Drilled:||No|
|Oiling Style:||Through pushrod|
|Machined for O-Ring:||No|
|Quantity:||Sold as a pair.|
Speedmaster Pontiac heads include valve sizes at 2.11" Intake, and 1.66" While the 2.11" valves are standard issue, the valve seat can be machined to accept a larger valve with minimal work. CNC Ported heads in this application will soon be available.
Speedmaster CNC ported cylinder heads are machined on dedicated 4-axis and 5-axis CNC machining centers to ensure accuracy and cost effectiveness.
On the CNC ported versions, combustion chamber, Exhaust and Intake Ports all fully CNC machined for better flow. CNC combustion chambers offer superior control over flame travel and quench area. CNC Ported heads eliminate human error and variation from port to port. Unsurpassed repeatability from one cylinder head to another that is commonly found in "Hand porting & Polishing"
Combustion chambers are exact in volume - so every cylinder has the same compression ratio. Each port is the same cross section - so every cylinder can reach higher true RPM potential. CNC machining produces ports and chambers to within tolerances of no more than .002"; in turn every cylinder can reach the same power potential and accurate tuning.
The head gasket we recommend for our Pontiac heads is Felpro #10171. (4.540 Bore) or Fel Pro#1016 (4.300 Bore)
Our heads are manufactured with the Ram Air IV pattern which requires Felpro #1233 gaskets.
Please measure for exact pushrod length once heads and rockers are fully installed. Deck machining, head gasket thickness and rocker arm style will all affect pushrod height.
All Speedmaster Pontiac heads use standard 14mm. x 750" reach, 5/8 hex, gasket seat sparkplugs like NGK R5671A-7, Autolite 3924, Champion RC12YC, etc. Remember that higher compression/ boost require a colder heat range sparkplug.
HEAD BOLTS / STUDS
Our Pontiac heads utilize standard Ram Air Iv head bolts or studs.The ARP head bolt part number is 190-3605.
We recommend the use of Edelbrock exhaust gaskets #7281 or any comparable item of your choice.