The development of 5.3-inch bore spacing technology in recent years has allowed drag racing’s leading engine builder to push displacements ever higher in the race for performance supremacy, as the engine blocks, cylinder heads, and crankshafts available today make cubic inch numbers once thought unimaginable a virtual commodity. 

Photo courtesy Automotive Engine Specialities

Engines displacing more than 1,000 cubic inches have already been built and tested on the quarter-mile, but it’s the smaller — if you can really call it smaller — 900-inch motors that are being utilized in growing numbers in Pro Modified competition, and the folks at Automotive Engine Specialities tipped us to the recent build-up and testing of a 920 cubic inch, monster big block Hemi at their facility in Illinois that will eventually find its way between the framerails of Jim Robbins’ C5 Corvette for competition in the PDRA’s tough Pro Nitrous eliminator.

The AES-built bullet is one of the loftiest projects, cubic inch-wise, ever undertaken by a drag racing engine builder. The Hemi is built is built upon a Dart Machinery billet block, with a Winberg crankshaft swinging GRP connecting rods and pistons from CP-Carillo, sealed with Total Seal rings. The throaty engine is fed through throttle bodies from Wilson Manifolds controlled by a Holley EFI system sitting atop a custom CFE sheet metal intake. Fuel is provided via a Waterman fuel pump and Weldon regulators, with Injector Dynamics supplying the fuel injectors. Harmonics are handled courtesy of a dampener from ATI Performance Products. 

AES developed the Hemispherical cylinder heads, which contain Victory 1 valves, Manton pushrods, PAC Racing springs, and Jesel rockers. Larry Jeffers Race Cars fabricated the custom headers, and the AES team turned to MSD Performance for the ignition system and Dailey Engineering for their oiling needs. Holley’s sister brand, NOS, will supply the four-stages of nitrous oxide to really make this thing turn the numbers.

Last week, the big Hemi was bolted up to AES’ engine dyno for the very first time and cranked out 1,785 horsepower (shown in the video linked below), but broke a valve spring in the process, leaving them well short of what they feel this new engine is capable of.

Robbins’ new mount that will carry the monstrous AES Hemi was built by Larry Jeffers Race Cars and will carry prominent sponsorship from AES and Holley, along with Chicago Lift Equipment Inc, Sticker Dude, Johler Demolition, Inc., Zizzo Racing, Jesel, CP Pistons-Carrillo, GRP Connecting Rods, and CFE Racing Products.

Robbins and company are planning to make their debut in late May when the PDRA rolls into the Memphis International Raceway.