Supertech Nissan RB26 86.50mm (+0.50) 30mm CH +15.5cc Dome 8.5:1 CR Piston - Set of 6 (Excl Rings)

This Supertech piston set is built for Nissan RB26 engines, specifically for builds requiring a 0.50mm bore increase, bringing the diameter to 86.50mm. You get a complete set of six pistons, each featuring a 30mm compression height and a domed top designed to achieve a specific 8.5:1 compression ratio with a 15.5cc volume. These pistons are forged, meaning they start as a single piece of aluminum that's heated and hammered into shape, making them inherently strong and well-suited for high-performance applications where stock cast pistons might not hold up. This set is designed to work with your existing RB26 engine components, but remember that it does not include piston rings, so you'll need to source those separately to complete the installation.

The forged construction is key here; it creates a denser, more uniform grain structure in the aluminum compared to cast pistons. This makes them much more resistant to the extreme pressures and temperatures found in a performance-tuned RB26 engine, reducing the risk of cracking or deformation. The specific 8.5:1 compression ratio achieved with these domed pistons is a popular choice for builds that plan to use forced induction, like turbochargers, as it provides a good balance between street drivability and the ability to handle boost without excessive detonation. The 30mm compression height is also a critical measurement that ensures proper piston-to-valve clearance and deck height when paired with the correct connecting rods and crankshaft.

When planning your engine build, keep in mind that these pistons are sold as a set of six and do not come with rings. You'll need to select a compatible set of piston rings that match the 86.50mm bore size and the specific ring groove dimensions on these Supertech pistons. It's also important to note that these pistons are not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation guide for precise measurements and recommended assembly procedures to ensure optimal performance and longevity of your engine.