When it comes to buying pistons, it’s obvious to get confused between cast and forged pistons. If you’re building a new powerful engine, possibly you’ve 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 in the way the piston blank is created. Cast pistons are manufactured by using a mixture of aluminum, alloys, and silicone. This mixture is poured in a mold to create a piston of general shape. The casting process helps in minimizing the final machining costs and requires less effort than forging. Although shelf-stock pistons are readily available, it’s not necessary that you find what you’re looking for. And this is where a forged piston comes into play.
What is Forged Pistons?
The main difference between a cast piston and a forged piston is the method of manufacturing. Typically, engines are factory-fitted with cast pistons. But when you need to boost the engine’s performance, forged pistons are the best option. 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 which is stamped by the use of a dye. The aluminum is pressed into heavy forging dyes to create the piston blank.
Benefits of Forged Piston
The cast pistons are commonly used in mass-produced engines because these 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 which makes it the best choice for an engine that’s slightly off the beaten path.
For your specific application, the cast piston may have the wrong compression ratio or it may lack a specific ring pack. Also, cast pistons are prone to damage due to their high silicon content. Sometimes, even a mild shock can damage cast piston because silicon gives the metal lubricity which limits 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 dimensions that are best fitted for the particular application.
If you look at most of the turbocharged and high-performance car models, they all have forged pistons. This is because custom pistons offer more durability against extreme heat, detonation, and pressure. These pistons are designed in a way that offers shatter resistance when exposed to extreme temperatures inside the combustion chamber.