Hypereutectic Dome Piston Set

The KB Pistons KB180-020 is a set of hypereutectic dome pistons engineered for demanding high-performance applications, including marine, drag race, circle track, street, and towing builds. These pistons are constructed from a 390 aluminum alloy with a high silicon content (16 percent), which provides a low expansion rate and allows for tighter piston-to-wall running clearances. Each piston in the KB180-020 set is precisely manufactured with a fully machined head and valve reliefs to accommodate various camshaft profiles. They feature triple spiral lock rings for secure ring groove retention, and CNC-machined pin bores to ensure straight and accurately sized bores for the wrist pins. An accumulator groove is integrated to aid in compression ring seal, while machined-in oil returns and diamond-finished skirts contribute to longevity and performance. This piston set includes wrist pins and spiral lock rings, but the piston rings are sold separately with available sizes of 1/16 x 1/16 x 3/16. The KB180-020 pistons are designed for General Motors SB Chevy engines with a specific bore size of 4.020 inches, a crankshaft stroke of 3.480 inches, and a rod length of 5.700 inches. The compression height is 1.561 inches, and the OE deck height is 9.025 inches. Compression ratios vary based on combustion chamber volume: 13.0:1 with 58cc, 12.3:1 with 62cc, 11.9:1 with 64cc, and 10.3:1 with 76cc chambers. The advertised piston weight is 563 grams, and the wrist pin weighs 145 grams. Please note that the standard bore size for this engine family is typically 4.000 inches, and the pin is centered.