Chevy Engine Block - Cutweight Horsepower

Swapping a Cast-Iron Block for an Aluminum One on a Chevy Small-Block V-8

Mark Stielow Sep 1, 2006 0 Comment(s)

Block: GM Performance Parts aluminum Bow-Tie
Details: 4.125-inch bores, 9.020-inch deck height, pressed in cylinder liners, set up for 3.500 mains and a wet-sump oiling system

Heads: Dart
Details: Fully CNC-machined cylinder head to achieve 59cc chamber volume, set up for 2.050/1.600-inch-diameter stainless, backcut valves with a valve-stem diameter of 11/32 inch, valve angle of 18-degree, poured from 356 virgin aluminum. Rocker stands machined to locate T&D shaft rocker stands at the proper height. Heads machined to attain 0.305- and 0.310-inch clearance of intake and exhaust valves at max lift from pistons at Top Dead Center (TDC) location of 0.013-inch proud of the deck. Compression ratio is 10.53:1.

Crank: Scat
Details: 4130 steel Ultralite Scat crank, 3.750-inch machined counterweights to clear aluminum webbing on all mains (see photo), riding on Clevite 909H series bearings-used because its half-groove design manages oil "bleedoff" better, which is critical in an aluminum block

Rods: Scat
Details: 6.000-inch steel, full floating pin in bushing, I-beam design riding on Speed Pro 7100 CH bearings

Pistons: Arias
Details: Forged aluminum, flat-top except for slight dish (equaling 15cc volume), 0.43, 0.43, 1/8-inch Speed Pro ring pack with gaps filed 0.020 inch - top, 0.25 inch - second, 0.030 inch - oil ring rail. Checked for size and condition, cleaned, lubed, and reinstalled.

Valvetrain Comp Cams
Details: Roller camshaft (PN#12-000-9, grind CS 4873/4874 SR 112 0) with 0.603/0.609-inch valve lift (with 1.6:1 rockers) on 236/242 degree duration at 0.050-inch lift on 108 degree lobe centers and a lobe separation of 112 degrees. Lobe lift of 0.377 and 0.381 int/exh.
Cam held in place with a COMP "wear plate" (PN#201). A COMP double-roller timing chain set (PN#3100) and cover (PN#208) spin the cam and Comp valvesprings (PN#26089-16) control the valve action. The valvesprings were shimmed to an installed height of 1.900 inch. The installed height pressure is 280 lb/in and the "over the nose" (at the top of the 0.600 inch lobe) pressure is 600 lb/in (at 1.300 inches high). Coil-bind is at 1.200 inch of valvespring height with the COMP titanium (Ti) retainers, locks, and ID-centered cups (COMP PN#4785-16) under the valvesprings. Crower roller lifters and tiebars were used.

Details: 1.6:1 ratio shaft-mount, billet rocker system (PN#2050) with intake 0.465-inch offset and exhaust 0.170-inch offset

Details: 3/8-inch-diameter, 8.550-inch-long pushrods (PN#25855-16)

Oiling System: Moroso
Details: '69 Camaro road-race pan, PN#21900, Moroso standard volume pump and pickup, pns 22100 and 24170 held in place with ARP oil pump stud (PN#230-7001) and actuated by Melling oil pump pushrod (PN#15-77) Intake - Wilson-prepped Edelbrock Aluminum, single-plane (PN#2994) with a 6.40-inch manifold height to clear the hood. Hand-ported by Wilson Manifolds for maximum flow. Wilson also welded in fuel-injector bungs and stands for their aluminum fuel rails and provided spacer for throttle body (PN#74202S3).

Fuel Injection: ACCEL
Details: Gen VII sequential fuel injection system. 36 lb/hr injectors, 1,200-cfm throttle body,

Fasteners: ARP
Details: head studs (PN#2344336), balancer bolt (PN#134-2503), cam bolt kit (PN#300-1001), distributor stud (PN#430-1701), intake (PN#434-2101), valve cover (PN#400-7613)

Gaskets: Fel Pro R.A.C.E. set (PN#2702) that comes with 4.200-inch gasket bore, 0.041-inch-thick head gasket

Custom components
Spacer to fill area between block China Wall and intake. Wheel to Wheel Powertrain created this aluminum piece and bolted it to the block with countersunk Allen head bolts.

Engine Assembled by: Wheel to Wheel Powertrain (W2W), Madison Height, Michigan


Comp Cams
Memphis, TN 38118
Dart Machinery
Troy, MI 48084
Wilson Manifolds
Ft. Lauderdale, FL
Wheel to Wheel Powertrain
Madison Heights, AK 48071


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