Supertech Honda B18B 81.5mm Bore -2.5cc Flat Top 9:1 CR Forged Pistons - Set of 4 (Excl Rings)

If you're rebuilding the engine in your Honda B18B and looking for a solid foundation, a set of forged pistons like these from Supertech is a smart move. These pistons are built to handle more stress than stock cast pistons, making them a popular choice for builds that aim for increased power or durability. They feature an 81.5mm bore size, which is a common upgrade over the stock 81mm, and a flat-top design with a -2.5cc dish, resulting in a 9:1 compression ratio. This compression ratio is a good balance for many performance applications, offering a noticeable bump in power without being overly aggressive for pump gas.

Supertech uses a forged aluminum process for these pistons, which creates a much stronger and more resilient part compared to cast pistons. This forging process aligns the grain structure of the aluminum, making them more resistant to deformation and cracking under high cylinder pressures and temperatures. The 81.5mm bore is a precise measurement, and these pistons are designed to fit right into the cylinder bore with the correct clearance, which is crucial for proper engine operation and longevity. Remember that these pistons are sold as a set of four and do not include piston rings, so you'll need to source those separately to complete the installation.

When installing these pistons, it's important to follow the manufacturer's recommended clearances and lubrication procedures. Proper ring gap and cylinder wall finish are critical for performance and oil control. These pistons are a significant upgrade for anyone serious about their B18B engine build, offering a well-built component that can support increased performance goals.