TO refresh your memory from last issue, the SD-455 that you see before you belongs to HPP contributor Melvin Benzaquen. We were using it as a mule for a fuel-injection swap into his '74 T/A when it expired on the chassis dyno during baseline testing. Cracking open the famed powerplant revealed a poor rebuild was the root cause of the engine failure.
Presented with the opportunity to rebuild the engine as well, the owner decided to upgrade the powerplant for reliability and employ some modern technology, so he sent the engine to RaceKrafters. That quest began in Part I with basic machining using state of the art equipment. Cylinder-wall finish and the valve-job procedure were notable technological improvements, fully explained in the first installment to go along with the basic machining and cylinder head porting.
In this issue, the engine will be assembled, and a Comp Cams hydraulic roller cam will be employed to exploit its advantages, such as lower friction and more aggressive ramps to open and close the valves more quickly by realizing more lift per degree of rotation. Craig Wise of RaceKrafters did all of the assembly work. He showed our Pontiac the same care and execution to detail that would be provided to a 1,000hp drag engine.
In the next installment, HPP will work with RaceKrafters to dyno test the engine with a carburetor and then with the high-tech EFI system from Mass-Flo EFI, but first we need to get some wrenches swinging!
SD-455 HEAD FLOWBob Wise's expertise with cylinder heads is quite apparent after examining the flow numbers. It must be recognized that these values were obtained with RaceKrafter's Super Mod porting, which works the bowl area, short turn, and valve angles. Then a gasket match is performed. All of the care that was represented in Part I of this series can easily be seen in the flow results.CFM flow at 28 inches of waterLift in InchesIntake FlowExhaust Flow0.10082.467.80.{{{200}}}156.3130.40.{{{300}}}228.8171.20.400263.2193.00.500278.8208.30.{{{600}}}292.2220.6HIGH PERFORMANCE PONTIAC ENGINE-BUILDUP WORKSHEET & SPECS
Engine Displacement: 463
Bottom End
Block: '74 SD-455
Preparation: Decked 0.020-in, bored, honed, align-honed
Cam Bearings: Dura Bond
Deck Height: 10.210 inches
Crankshaft: Eagle cast-steel 4.21-stroke, PN 104554210
Preparation: Mic'd, balanced
Balancer: Stock
Rods: Eagle H-beam, forged-steel, stock-length, PN CR56625P3D
Preparation: Clean, measure, balance
Bearings: Main, Clevite PN MS-667P; rod, Clevite PN CB-758-H
Preparation: Dress
Pistons: SRP forged flat-top with valve reliefs, PN 149721
Compression Height: 1.480 inches
Preparation: Clean, measure, balance
Piston-to-Deck Height: Zero
Piston Pins: SRP, tool-steel
Method Used to Retain Piston Pins in Pistons: Spiral locks
Rings: Perfect Circle, moly-faced ductile iron (11/416, -11/416, -31/416), PN 315-0032-065
Preparation: File-fit, deburr, clean
Rod Bolts: ARP
Oiling System
Oil Pan: Stock
Oil Pump: Melling high-volume, PN M-54-F
Preparation: Check, clean, weld pickup
Heads
Casting Number: 16 Round-Port SD
Head Mods: Bowl port and polish, milled 0.050 Combustion-Chamber Volume: 98cc
Compression Ratio: 9.49:1
Intake-Port Volume: 206cc
Exhaust-Port Volume: 186cc
Valves, Intake: Ferrea SS 2.11-in, PN F5073
Valves, Exhaust: Manley SS 1.77-in, PN 11355-8
Angles Used in Valve Job
Intake: 30-45-60-75-82-deg
Exhaust: 30-45-55-82-deg
Head Bolts: ARP, PN 190-3603
Retainers: Comp Cams, steel 10-deg, PN 740-16
Keepers: Comp Cams, Super Locks 111/432 10-deg, PN 611-16
Valveguides: Bronze
Valve Seals: PEP, 111/432x0.500
Spring Cups: Comp Cams, 4770-16
Rocker Studs: ARP 71/416-in, PN 235-7204 Rocker Arms: Comp Cams roller 1061-16
Rocker Arm Ratio: 1.65:1
Pushrods: Comp Cams, High Tech, PN 7775-16
Diameter: 51/416-in
Length: 8.650-in
Guide Plates: Comp Cams, PN 4851-8
Cam
Brand: Comp Cams hydraulic-roller, PN K-51-423-9
Duration at 0.050: 224/230-deg
Lift: 0.552/0.561
Lobe Separation Angle: 110-deg
Installed Position: 105.5-deg
Lifters: Comp Cams roller
Valvesprings: Comp Cams, dual, PN 987-16 Seat Pressure: 121 lbs
Open Pressure: 328 lbs
Timing Chain: Cloyes double roller
Induction
Carb: See next issue.
Intake Manifold: See next issue.
Ignition
Distributor: Stock points-type
Coil: Stock replacement
Wires: Stock replacement
Exhaust
Manifolds: Reproduction iron SD
Outlet Size: 2.5-inch
Gaskets
Brand: Fel-Pro
Ancillary Components
Flexplate: RPW, 1845500
Flexplate Bolts: ARP, 200-2904
Plug Kit: Pioneer, PE-115-R
Rear Seal: Fel-Pro, BS-40012
