CP Piston & Ring Set for Subaru EJ20 WRX - Bore (93mm) - Size (+1.0mm) - Compression Ratio (8.5)

This is a set of forged pistons and rings from CP Pistons, specifically made for the 2002-2005 Subaru Impreza with the EJ20 WRX engine. These are a 93mm bore size, which is 1.0mm oversize from the factory specification, and they feature a compression ratio of 8.5:1. If you're rebuilding the top end of your EJ20 engine, especially if you're looking to handle more power or are dealing with worn cylinders, a set of quality forged pistons like these is a solid choice.

CP Pistons are well-known for their strength and durability, making them a popular option for performance builds and high-mileage engines. These pistons are forged from high-strength aluminum alloy, which is much stronger and more resistant to detonation and heat than cast pistons. The 1.0mm oversize bore means these are intended for engines where the cylinders have been bored out to clean up any imperfections or to achieve a larger displacement. The 8.5:1 compression ratio is a good balance for many modified EJ20 engines, offering a bit more grunt without being too sensitive to fuel quality.

This set includes the pistons and the necessary rings to complete the installation. When installing these, ensure your engine block has been properly machined to the correct 93mm bore size and that all tolerances are checked according to CP Pistons' specifications. Because these are an oversize piston, proper cylinder wall preparation is critical for a good seal and long engine life. Please note that this part is not CARB approved and cannot be shipped to California.