Sometimes, an engine build has more goals than just raw horsepower. This 427 small-block engine build from Keith and Jeff Dorton at Automotive Specialists not only aims to make some serious steam, but also to do so in an eye-catching way, as it will be showcased between the framerails of a killer show car. Fortunately for us, our friend Jeff Huneycutt of The Horsepower Monster was able to document this interesting build.

Since the owner wanted a small-block-based 427, there was some work to be done to achieve the displacement. Generating 427 cubes from a 9.025-inch deck-height-block is no small feat. But, fortunately for the customer, it’s a challenge that the Dortons have successfully completed plenty of times in the past, and the Horsepower Monster has a deep dive into what exactly it takes to achieve such a feat.

www.youtube.com/playlist?list=PLE1lJL23C1R8U91YtE0RKugWT1j6owOMP
The Horsepower Monster has a five-video series on how to get 427 cubic inches out of a 9.025-inch-deck small-block Chevy

Literally Making A 427-Cube  Mountain Out Of A Mole Hill

Starting with a solid foundation for the project, a cast-iron Dart SHP block with the stock 9.025-inch deck height, but with 4.125-inch bores is used. A four-inch stroke crank fits in the block thanks to some clearancing work with a die grinder, to make room for the rod bolts as they swing by. The crankshaft itself is a Molnar Technologies forged unit, as are the 5.850-inch-long H-beam connecting rods.

Hanging off of those rods is a set of 4.125-inch MAHLE forged Powerpak pistons. Dorton chose a set of dished pistons with a total volume of 16cc to set the compression ratio at 10.0:1 with the four-inch stroke, since the engine will live on 91-octane pump gas. The crank is secured into the block with steel splayed four-bolt main caps and high-grade 7/16-inch main bolts and 3/8-inch outer bolts.

A Melling oil pump uses a Milodon pickup tube to drink oil from the Milodon pan. The deep sump oil pan has both a crank scraper and a louvered windage tray to help fight windage in this long-stroke beast. A Wieand water pump finishes off the short-block.

Building a 427 out of a standard deck-height small-block Chevy is no easy task. Stuffing a fout-inch stroke in that little block takes some serious, purposeful grinding of the block, as well as matching of components.

Top of the Mountain

A set of SCE .039 compressed-thickness multi-layer steel head gaskets and ARP head bolts seal the AFR 23-degree aluminum cylinder heads to the block. The 65cc chambers are fully CNC machined and outfitted with 2.05-inch stainless intake valves and 1.60-inch stainless exhaust valves. The intake ports have been opened up to 195cc of runner volume and flow 280cfm at .550 inch of lift. The 64cc exhaust ports have been raised .100 inch and flow 218 cfm. PAC dual valve springs have been shimmed .070 inch to provide 175 pounds of seat pressure and 420 pounds of open pressure.

Controlling the valves is a solid-roller camshaft from Jones Cam Designs. It features .615 inch of valve lift on both the intake and exhaust, with a split duration of 250 degrees at .050 inch on the intake and 258 degrees on the exhaust, with a 112-degree lobe-separation angle. A Cloyes Hex-A-Just double roller timing set locks the cam to the crank’s rotation, and a Cloyes billet timing cover has an indexable cam stop to dial in endplay.

Riding on the cam lobes are Morel solid roller tie-bar lifters. A set of 7,800-inch-long 5/16-inch-diameter pushrods are used to maintain proper valvetrain geometry. The aluminum 1.5:1 ratio rocker arms are secured with beefy 7/16-inch rocker studs and polylocks.

The Piece de Resistance

The special intake manifold and induction system are really what sets this 427-cube small-block Chevy apart. It’s not just an Inglese system, it’s specifically a Jim Inglese Eight Stack Systems (the name of the company she started after selling Inglese) EFI system. This is not an off-the-shelf induction system, but rather a custom-assembled system specific to this application.

This EFI system from Jim Inglese Eight Stack Systems houses an octet of 57 lb/hr fuel injectors and is controlled by a Holley Terminator X ECU. The air horns are interchangeable for different sizes in order to fine-tune the powerband.

The system is an absolute work of mechanical art, that harkens back to the days of individual Weber carbs, but with all the modern convenience and performance of electronic fuel injection. It hides the modern 57 lb/hr fuel injectors beneath the fuel log and has CNC-machined air stacks available in a variety of sizes to suit the engine. A Holley Terminator X ECU runs the fuel injection system thanks to an MSD billet cam position sensor in place of the distributor and individual LS-style coils.

The sound of the engine on the dyno is incredible, so, combined with its killer looks checks two of the three boxes on this engine. Number three is making good power. After some quick tuning from Jeff, Keith pulled the handle and let ‘er rip. The results? 566 horsepower at 5,900 rpm and 571 lb-ft of torque at 4,700 rpm. Huneycutt points out that the engine’s low-RPM performance is going to be extremely stout. Not bad for a show-stopping engine, that will run and drive in any weather, and blow the tires off at the drop of a hat.

566 horsepower and 571 lb-ft of torque from a 427 cubic-inch small-block work of art that will start and drive anywhere, anytime, on pump 91-octane is hard to shake a stick at.