Dart PRO1 Small Block Chevrolet Platinum 230cc/64cc 23° Aluminium Cylinder Head Assembled Suit Solid Roller Cam. Max lift .700"
Maximum performance/full competition, unlimited oval and super classes. 7,000 RPM, 400 cubic inch engines.
PRO1 23° 230cc Platinum series heads are intended for maximum effort competition engines with large displacements and very high RPM usage.
Long wearing Bronze valve guides, screw-in studs, multi-angle intake seats with hardened, radiused exhaust seats are standard. Best of all, our precision cast ports produce outstanding airflow without time consuming porting.
Assemblies include Stainless Steel valves, premium springs, locks, retainers, studs, guide plates and seals.
Heads are sold individually
Part# 11711143P
Material: RMR Cast Aluminium Alloy
Comb Chambers: 64cc
Intake Valve Dia: 2.08”
Intake Port volume: 230cc
Intake Port Dim: 2.180” x 1.190”
Int Port Location: Stock
Intake Gasket: Fel-Pro # 1206
Exh Valve Dia.: 1.600”
Exh Port volume: 75cc
Exhaust Port Dim: 1.375” x 1.325” w
Exh Port Location: Stock location & bolt pattern
Exhaust Gasket: Fel-Pro# 1405
Flow, Intake: 308cfm @ .700” lift / 28”
Flow, Exhaust: 207cfm @ .700” lift / 28”
Head Bolts: Dart bolt kit PN# 66220011
Head Studs: Dart stud kit PN# 66120011
Manifold: Alum Single Plane Dart PN# 42411000
Milling: Min. 58cc = .060” (.0065” = 1cc) Flat Mill
Angle mill .125” safely / .200” = 49cc 1.5° (carefully)
Pistons: Most 23°aftermarket pistons.
Push Rod length: Stock thru .100” Should always measure (Stock length = 7.800”)
Push rod Guide Plate: Dart adjustable guide Plate PN# 27001410
Retainers: Steel (10°)
Spark Plug: Angle, .750” reach, gasketed seat
Spring Pockets: 1.550” OD (.030” deeper max)
Springs: Our Assembly: 1.550D = 215# @ 1.900” / .690” max
Valve Length: 5.015” ( .100”) (Std. = 4.915” w/1.437)
Valve Stem Dia: .3415” - 11/32”
Valve Train: STD SBC 3/8” or 7/16” stud mount
Valve Guides: .439” OD Int = Mag-bronze Exh = Mag-bronze (.002” press)
Valve Guide length: 2.100”
Valve Guide clearance: .0014” - .002” (with our .3415 dia. valve stem)
Valve Guide Spacing: 1.890” moved .030” from stock
Valve Seats: Powdered Metal, .006” press
Valve Seat dim. Int - 2.160”x 1.810” x .350” Exh - 1.650”x 1.350”x .350”
Valve Seat angles: Int = 32° - 45° - 60° - 70°- 80° Exh = 37° - 45° - radius
Stud Girdle: Dart stud girdle PN# 64110002
Torque: Head Bolts = 70 ft/lb
Rocker Studs = 55 ft/lb
Manifold = 35 ft/lb
Block Use: Any SBC Iron or Aluminium
Weight: 23 lbs Bare – 28 lbs Assembled
SBC SB Chev 23 degree cylinder heads
