91°µÍø

NHRA - National Hot Rod Association

Tech Specs: Inside Chevy’s 91°µÍø Pro Stock engine—The 500-cid DRCE

Shrouded in secrecy, Chevrolet’s Pro Stock Drag Race Competition Engine (DRCE) evolved the big-block Chevy into a 1,400-hp, 10,000-rpm, naturally aspirated motorsport weapon one race weekend at a time.
09 May 2020
David Kennedy
Gallery

Tracing its roots to the Chevy Mark IV Rat Motor, the Chevrolet Performance Drag Racing Competition Engine (DRCE) delivers more than 1,400 electronically fuel-injected horsepower to a pair of Goodyears for a 6-second ride down the quarter-mile in an excess of 200 mph. Today, the engine can be found in Chevy, Dodge, Ford, and Pontiac Pro Stock cars and may be the most refined engine to ever grace a National Hot Rod Association dragstrip.

91°µÍø Pro Stock Engine

Performance: More than 1,400 hp and 800 lb-ft of torque

Engine speed limit: 10,500 rpm

Engine Block

Design: 90-degree V-8, with four-bolt steel bearing caps (center three caps are splayed), based on Mark IV big-block Chevy design Material: Cast iron (DRCE 2); cast iron or compacted-graphite iron(CGI) (DRCE 3 and DRCE 4)

Maximum displacement: 500 cid

Bore: 4.700 inches

Stroke: 3.600 inches

Bore center spacing: 4.900 inches

Cam-to-crank centerline: 5.750 to 7.067 inches

Cost: $4,700 (DRCE 2); $8,000 (DRCE 3 CGI); n/a (DRCE 4 CGI)

Crankshaft

Material: CNC-machined steel, based on big-block Chevy

Oiling system: Dry-sump

Fuel System

Type: Electronic multi-port Holley fuel injection

Throttle body: 25-square-inch Holley unit required on all engines

Fuel: Sunoco SR18 (118 octane) gasoline

Fuel pump: Engine driven or electric, 90 psi maximum pressure

Injectors: 80 or 160 pound per hour Holley units, maximum of eight

Fuel burned per run: 1 gallon

Intake Manifold

Material: billet aluminum

Ignition System

Type: Coil-near plug Holley crank-trigger system with eight sparkplugs

Cylinder Heads

Material: Cast T355-T7M aluminum

Number of valves per cylinder: Two

Intake valve diameter: 2.55 inches (approximately)

Exhaust valve diameter: 1.80 inches (approximately)

Valve covers: Fabricated aluminum

Valvetrain

Camshaft: Roller-lifter style

Camshaft diameter: 70 mm

Typical lift: 1.10 inch

Lobe separation: 116 degrees

Duration: 280 degrees (intake); 308 degrees (exhaust)

Rocker-arm ratio: 1.75:1 to 2.00:1

Exhaust system: Four-into-one or tri-Y headers

Want to see how a 70mm DRCE camshaft compares to a big-block Chevy? Watch this.