High Performance Engine Pistons

When purchasing pistons engine applications set up for high performance use will have increased horsepower from choosing a higher compression version with either a flat top or dome design over a stock piston with a dished top.

Utilizing stronger pistons, such as forged offerings, allows for longer life and the ability to handle more horsepower. This provides a more reliable engine, removing the pistons as the weakest link in the rotating assembly.

Pistons take the explosive pressure caused by the ignited fuel and air mixture in the engine against them and push down in the engine block cylinder with the connecting rod to the crankshaft rod journal in order to rotate the flywheel and produce engine power output. They are joined to the connecting rod via a piston wrist pin that is either pressed into the piston or with a floating design, using lock rings. This allows the piston to stay lined up with the cylinder block bore while the connecting rod hinges as the other end of it swings with the crankshaft.

On a typical Chevy 350 engine revving up to 6,000 RPMS, the piston would have a maximum average speed of almost 40 MPH as it slows down every time it hits top and bottom dead center during a revolution. The engine rpm and stroke affect how fast pistons travel. The formula for determining the average piston speed in feet per minute is engine stroke x engine RPM / 6 (fixed number used in all calculations for piston speed). To convert the answer to miles per hour, first multiply the result by 60 (number of minutes per hour) to convert the "feet per minute" answer to "feet per hour". Next, divide the answer by 5,280 (number of feet in a mile) to get the answer in mph. For example, a Chevy engine with a 3.48 stroke revving at 6,000 rpms would use the following calculation: 3.48 x 6,000 / 6 = 3,480 (feet per minute). Then, 3,480 * 60 = 208,800 (feet per mile). Finally, 208,800 / 5,280 = 39.55 (miles per hour).

The best method for cleaning engine pistons is with them out of the engine block. If the pistons are in the block and you are trying to clean the tops of them, great care must be taken not to let any debris get around the edges which can then damage the cylinder walls and rings. The most commonly used chemical for cleaning automotive engine pistons is carburetor cleaner. There are other options for chemically cleaning pistons. However, care and research must be taken so that the piston is not damaged from too harsh of a chemical. For mechanical cleaning, a nylon brush or other soft cleaning tool will help to break up debris. Other types of cleaning tools can be used, but with great care not to scratch or damage the pistons. Also, any debris left from cleaning brushes or tools needs to be thoroughly cleaned off before reinstalling pistons.

There are different piston top shapes available depending on the application. Flat top pistons are nearly level on top and can be used in performance applications to help increase the engine compression ratio. Dish pistons have a valley or depression in the surface, which reduces compression and can be found in factory / stock applications as well as in engines with turbocharger or supercharger setups. Dome pistons are typically found in high performance and racing applications, with protruding or raised surfaces on the top of the piston. Dome pistons raise engine compression ratio as they reduce the amount of space in the combustion chamber. In all cases, it is very important to confirm the amount of room you have available before making a purchase. If the wrong pistons are ordered, the cylinder head valves or other surfaces can make contact with the top of the pistons, causing engine failure.

Most stock pistons are cast, meaning the aluminum is melted and poured into a mold to create its shape. It is then machined to provide the proper smooth finish. Hypereutectic pistons are made similarly, but with more silicon content. This helps to reduce piston expansion in the cylinders, allowing tighter tolerances between the piston and the block bore, improving performance. Forged pistons are made by softening the aluminum and then with a press, forcing the aluminum into the piston shape under great pressure, pushing the alloy material grains tight against each other. This creates a very strong piston, capable of handling large amounts of horsepower. Most high performance pistons are forged, providing the strength needed to handle forced-induction, nitrous, and high-compression race applications.

When it's time to add new piston engine parts, and other components to your motor, you have many types and sizes to choose from. Whether a stock rebuild with cast pistons, or a high performance race engine with forged pistons designed with a dome, JEGS has what you need to complete your next project. Browse our selection of Mopar, Ford, and Chevy pistons for sale and complete your engine build or rebuild today!