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)
Sucp_0609_14_z Chevy_engine_block_swap Edelbrock_intake 2/22

An aluminum Edelbrock 18-degree Victor Jr. intake manifold has been heavily chiseled on by Wilson Manifolds for maximum flow. Notice the diamond in middle (arrow) with sloping angles to the port entrances and the holes in the carb mounting plate to "pin" the Wilson carb spacer for exact placement. Cool.

Sucp_0609_15_z Chevy_engine_block_swap Intake_valve 3/22

Wilson further prepped the intake manifold for maximum fuel-injected power by machining holes for the fuel injectors at 15 degrees from vertical and welding the mounting bungs into each port (finger). This positioning showers the backside of the intake valve with the majority of the fuel spray. Note: the slick Wilson fuel rail mounts and the mounts welded to the intake to hold the rails in place on the Accel injectors.

Sucp_0609_16_z Chevy_engine_block_swap Dart_cylinder_heads 4/22

When making major changes to the cylinder head valve angle when building an engine, a major issue to deal with is the angle "stackup" that show up at the intake manifold to cylinder head and block mounting face. To address this issue, the Fel-Pro intake gaskets are taped to the fully assembled Dart heads and the intake set in place. Notice the installed timing chain cover (the cam is installed and degree'd) and ATI harmonic balancer.

Sucp_0609_17_z Chevy_engine_block_swap Cylinder_heads 5/22

This is where the experience of an engine builder is invaluable. The Dart cylinder head castings sit approximately 0.250 inch high off the 'china wall' of the Bow-Tie block and require an aluminum spacer to be bolted to the block (after drilling and tapping 0.250 inch threaded holes in the "China Wall") with countersunk Allen bolts. Notice the Manley drainback oil stands installed the lifter valley (arrow), the massive Bow-Tie cast into the front of the block and the gold anodized Allen plug that is sealing off the dry-sump oiling passage that is part of this very capable Bow-Tie block.

Sucp_0609_18_z Chevy_engine_block_swap Electronic_fuel_injection 6/22

The electronic fuel injection and ignition systems are operated by an ACCEL Gen VII DFI system. An ACCEL Universal Wiring Kit (PN#77021), which features an unterminated wiring harness, were used to make a custom-fit harness. This kit includes all the connectors and terminals you will need to build a harness. Mike Brown, at Wires and Pliers, used this kit as a starter to whip up one of his ultra-custom engine harnesses for a very clean appearance. He also integrated an ACCEL wide-band O2 system into the harness at the same time.

Sucp_0609_19_z Chevy_engine_block_swap Throttle_body 7/22

The Accel billet throttle body is similar to a carburetor with the two small primary throttle blades and large secondary throttle blade. Notice the Accel dual sync distributor (PN#77100) trigger and MSD spark plug wires. The dual sync distributor gives the Engine Control Module (ECM) the cam sync signal to enable sequential fuel injection. Like most electronic fuel injection engine buildups, an adjustable distributor slip collar was required to get the distributor gear properly lined up with the cam gear for the computer to "find" top dead center on the engine.

Sucp_0609_20_z Chevy_engine_block_swap Valve_lash_adjustment 8/22

Since this engine is equipped with a roller cam, there really isn't any "break-in" procedure. It was just warmed up and then shutdown so the valve lash could be set at 0.024 inch on all rockers. Then the calibration work was begun. This started with just getting the engine to idle properly, then focused on getting max power from a run.

Sucp_0609_21_z Chevy_engine_block_swap Motor_calibration 9/22

The calibration work that is performed on the dyno is usually focused on wide-open throttle (WOT) applications under load. These are difficult to perform with the engine in the car (there just isn't enough road, traction or speed limit to give it justice). The calibration work performed in the vehicle encompasses everything else: idle quality, driveability, deceleration, cold start, hot soak, etc.


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