The GM 602 crate engine is a factory designed performance motor produced by General Motors that is intended for racing and off-road use. The engine derives its more common 602 moniker from the last three digits of its part number identification of 88958602. These engines are generally popular for circle track and other racing applications where engine size and power is strictly regulated to encourage more competitive racing among participants.
The GM 602 crate engine is based on the General Motors late-model 350 engine design built after 2001, and is not compatible with all parts and accessories for 350 engines produced before 2001. It has a cast iron block and cylinder heads, and there are no provisions for emissions controls. The engine is a 90-degree V8 design with a centrally located camshaft. The 602 is designed for off-road use only and is not intended for street use. This engine is sealed, which means that it is built with specialized bolts that cannot easily be removed. This is done to ensure against tampering or modification of the engine in order to increase its power.
The 602 engine is constructed with a GM Performance intake manifold that has no provisions for an EGR valve or hot air choke. It is a dual plane manifold constructed of aluminum and designed to work with a standard flange Holley carburetor.
The engine is equipped with GM Vortec cylinder heads that are constructed of cast iron. The heads have 1.94-inch intake valves and 1.5-inch exhaust valves, and 3/8-inch pressed-in rocker arm studs. The heads accept intake manifolds with an eight-hole bolt pattern, with four bolts per head.
The crankshaft in the 602 engine is cast iron and secured by four bolt main caps, and is designed to use a one-piece rear main oil seal. The connecting rods are powdered metal and the pistons are cast aluminum. The engine has a 4-inch cylinder bore and a 3.48-inch crank stroke that produces a 9.1-to-1 compression ratio.
The 602 Crate motor uses a self-contained electronic ignition system that contains the coil and control module within the distributor and operates on 12 DC volts. The firing order of the engine is 1-8-4-3-6-5-7-2.
The 602 engine uses an internal oil pump that produces 40 psi of pressure at 2,000 rpm. The oil capacity of the engine is 8 quarts and the oil pan is designed specifically for circle-track racing applications.
The GM 602 Crate Motor is designed to run on 92 to 93 octane fuel and produces 350 horsepower at 5,000 rpm and 390 ft.-lb. of torque at 3,800 rpm.