When buying pistons, it’s obvious to get confused between cast and forged pistons. If you’re building a new powerful engine, you’ve probably decided everything- from the new crankshaft to cylinder heads. But have you decided which pistons will best suit your application? You must have heard two terms related to pistons- cast and forged.
The basic difference between these two is how the piston blank is created. Cast pistons are manufactured using a mixture of aluminum, alloys, and silicone. This mixture is poured into a mold to form a piston of general shape. The casting process helps minimize the final machining costs and requires less effort than forging. Although shelf-stock pistons are readily available, you don’t need to find what you want. And this is where a forged piston comes into play.
What are Forged Pistons?
The main difference between a cast piston and a forged piston is the manufacturing method. Typically, engines are factory-fitted with cast pistons. But forged pistons are the best option to boost the engine’s performance. Forged pistons are the first choice of racing professionals and custom engine builders because they can be easily customized to any configuration. Unlike cast aluminum pistons, forged pistons have metallurgical characteristics. This process uses a single lump of billet alloy stamped with a dye. The aluminum is pressed into heavy forging pigments to create the piston blank.
Benefits of Forged Piston
Cast pistons are commonly used in mass-produced engines because they are cost-effective for the manufacturer. But racing tuners and custom engine builders prefer forged pistons because of the forging’s inherent strength. A forged piston is stronger and more durable, making it the best choice for an engine slightly off the beaten path.
For your specific application, the cast piston may have the wrong compression ratio or lack a particular pack of rings. Also, cast pistons are prone to damage due to their high silicon content. Sometimes, even a mild shock can damage the cast piston because silicon gives the metal lubricity, limiting heat expansion. Forged pistons, on the other hand, are best for high-performance applications. These pistons provide a high compression ratio inside the engine, which helps the engine in producing more power. The dimensions and characteristics of custom pistons can be modified during the machining process to achieve a piston design and sizes that are best fitted for the particular application.
Most turbocharged and high-performance car models have forged pistons. Custom pistons offer more durability against extreme heat, detonation, and pressure. They are also designed to provide shatter resistance when exposed to extreme temperatures inside the combustion chamber.
