While modern technology might be able to make tons of power from smaller and smaller displacements, there is still no substitute for the brutal, raw sound of a big-inch big-block engine. This particular engine was built by Prestige Motorsports for a customer, and they shared the video of its dyno run on their YouTube channel.
Starting with a World Products 9.800-inch-deck Merlin iron block, the cylinders were bored to 4.600 inches. A forged-steel, 4.375-inch-stroke crankshaft was bolted into the four-bolt mains. Forged H-beam rods connect the crankshaft to a set of 2618 pistons with a 10cc dome to bring the big-block’s compression to 10.0:1.
Topping off the short-block is a pair of Prestige’s rectangle-port aluminum cylinder heads. A custom-ground COMP Cams hydraulic roller is the brain of the engine, controlling 2.300-inch intake and 1.880-inch exhaust valves. Billet aluminum roller rocker arms translate motion from the cam to the valves. A Billet Specialties front-end accessory drive spins all the accessories needed for a street car.
A Weiand single-plane intake manifold tops off the combination, fitted with an Accufab 4150-style four-barrel throttle body. The engine is port-fuel-injected, controlled by a Holley Terminator X ECU and harness. On the dyno, the combination spins to 6,000 rpm. However, it doesn’t just spin that high, but makes power up there, peaking at 690.4 horsepower at 5,800 rpm and 671.6 lb-ft at 4,800 rpm.
That’s a whole lot of grunt for the street, and once the big-block Chevy is dropped into its eventual home — a 1967 Chevrolet Chevelle — it will have no problems getting from point A to point B, laying rubber the entire way, with power steering and blasting cold air the whole time.