All top engine builders recognize that the exhaust system exerts tre­mendous influence on engine per­formance, particularly with regard to breathing efficiency and torque curve positioning within the required RPM range. Thoughtful exhaust tuning can often promote additional torque production and the enormously valuable ability to position that torque in the most favorable part of an […]

Initial engine startup and break-in procedures are vital to the success of every new racing engine. Many top engine builders treat initial startup and break-in with nearly the same respect as with a NASA shuttle launch. Countless hours of prepa­ration and a substantial amount of money have been invested to build the best possible engine. […]

Camshafts are the command cen­ter of the engine. As a primary con­tributor to VE they govern the precise valve action that controls the intake and exhaust system and thus exert enormous influence on an engine’s power potential. Choosing a cam­shaft for any given racing application can be a daunting experience for even the most experienced […]

The intake manifold is one of the principal tuning components of any competition engine. Its con­figuration and dimensions actively influence the production of torque and horsepower and their placement within the engine’s effective oper­ating range. Consequently, a poor intake manifold selection is often a contributing cause of lost or mis­placed power and/or poor throttle response. […]

Race-prepared cylinder heads are the most important component in a racing engine. Most of the power an engine makes comes from the cylin­der heads and their ability to fill the cylinders and evacuate them effi­ciently. Not surprisingly, a substan­tial portion of a racing engine budget goes to cylinder heads to ensure a competitive build. The […]

Virtually all modern engines use bearing shell inserts for the crank­shaft, rods, and camshaft. Mains and rods use a split bearing with upper and lower half-shells. Cam bearings are mostly single-piece, ring-style inserts that are pressed in place with an interference fit in each housing bore. Most bearing inserts have a thick metal backing made […]

Stroke length aside, connecting rods are one of the basic tunable com­ponents in a competition engine. As rod length (center to center) varies, it affects piston motion such that it can be used as a primary tuning ingredient. By influencing piston acceleration and velocity it dictates the rate at which a differential is cre­ated between […]

Racing pistons are manufactured from aluminum forgings. Certainly plenty of racing occurs with cast and hypereutectic pistons, but only where class rules forbid aluminum forgings. This book deals with high-level racing engines, so this discussion primar­ily pertains to forged racing pistons. With the exception of clearances and certain performance features, cast and hypereutectic pistons can […]

Like most parts in a competition engine crankshafts live a harrowing existence somewhat akin to having eight bullies beating you up over and over again. A high-end racing engine can produce a combustion pressure of about 1,400 to 1,500 psi. For example, if you apply that pres­sure to a 4.185-inch-diameter piston, as found in a […]

Cylinder block selection is mostly application specific and is often limited by racing series rules. The requirements of your specific application may influence your choices based on block material, bore spacing, main cap material and configuration, cam location, and machinability. Selection might be limited to a two-bolt main stock pro­duction block or it may be […]