Blown, Big-Inch Ford Windsor 427 Engine: Animal Unleashed

The Engine

At one time we would have... 

   

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At one time we would have been surprised to see an oxygen sensor in a carbureted engine's exhaust system, but not now. It's there for the dyno's data-acquisition system only, and has nothing to do with feeding information back to the carburetor.

Holley's goal of bypassing the crate-engine route and assembling an engine from parts worked well, going together with a minimum of hassles and easily handling the impressive power and torque. Like most moderate-rpm, higher-boost blower engines, this motor uses high-quality parts-there's nothing low-buck about this approach. But there's also nothing here we'd label exotic or completely off the financial scale we'd have to call Department of Defense accountants to add up the numbers. In fact, on a dollar-per-horsepower basis, this engine is likely a bargain, and the internal clearances and specifications for things such as bearing and cylinder-wall clearance, ring thickness and placement, and piston weight would look rather standard to anyone with hot-rod V-8 experience.

The heavy architecture is from Dart Machinery, including a stout Dart block, Dart Pro 1 aluminum cylinder heads, a premium Lunati forged crankshaft, Lunati Pro-Billet connecting rods, Lunati forged-aluminum pistons with an 8.5:1 compression ratio, and an all-Lunati mechanical-roller valvetrain with mountainous 0.668/0.668-inch lift and week-long 262/268 degrees of duration at 0.050-inch valve lift. A Jesel belt-drive connects the crank and camshafts.

Airflow and fuel-delivery issues key to making power were handled by Holley and Wilson Manifolds. Wilson took a Holley Nitrous Pro Flow single-plane intake, gave it a full port job, fitted a 1.5-inch-tall, four-hole carburetor spacer, then turned to the cylinder heads. These were comprehensively CNC-ported by Wilson, all the way to breaking through into the pushrod passages and having to sleeve them to retain the port's airtight integrity.

Keeping with the straightforward theme, this engine's ancillary systems are blessedly simple. The wet-sump oiling is provided by a Melling high-volume pump and somewhat trick Milodon deep-sump pan. The ignition is all standard MSD gear, and the dyno exhaust is large-tube 4-into-1 dyno headers blasting into Vrbancic Brothers' immense dyno mufflers.

Yes, there's more to this than rebuilding an old 5.0. But if you're past the point of having a jar of parts left over after you assemble an engine, you might consider tackling this one yourself. It would be quite an accomplishment.