A nice idle and great part throttle drivability aren’t characteristics you would expect to find in an engine build capable of 2,500 horsepower. Nelson Racing Engines has built just that motor and posted the engine dyno runs to their YouTube channel.
Built for a 1955 Chevy Bel Air in Australia; this project started with a 632ci BBC. Internally, they installed a Callies Magnum crankshaft, Oliver billet connecting rods and JE forged pistons. To button up the 632, they used a Billet Fabrication aluminum oil pan, and Brodix Big Brodie Heads.
To help this monster engine breathe, an in-house designed NRE Alien billet intake and Tial blow off valves were used. This build also uses a dual injector setup and an Electromotive ECU with Octane On Demand. Octane On Demand allows the owner to install a secondary fuel tank and run pump gas while at idle and cruising around and race gas at higher loads.
To help make this build as street friendly as possible, Nelson Racing designed a custom exhaust that allows the dual 44 mm Tial wastegates to recirculate the excess boost directly back into the exhaust stream as opposed to a vent to atmosphere design.
At an extremely conservative boost target of 11 PSI, this motor made 1,298 horsepower at 6,200 RPM and 1,274 lb-ft at 4,800 RPM. After slowly raising the boost target over several pulls and bringing the headers to a glowing red, the final numbers this street engine put out were 1,843 horsepower at 5,700 RPM and 1,714 lb-ft at 5,400 RPM.