6pc Forged Dish Piston Set, 3.905" Bore

The United Engine & Machine (UEM) IC944-030 is a set of six premium forged pistons engineered by Icon. Crafted from 4032 alloy, which contains 11% silicon, these pistons are designed to manage thermal expansion effectively, allowing for tighter piston-to-wall clearances and reduced wear on the skirts and pin bores. This material composition makes them an excellent choice for high-performance street applications and setups with mild boost. These pistons feature a dish-type design with a -21cc volume, contributing to a 9.6:1 compression ratio with a 60cc cylinder head. The set includes wrist pins and utilizes 5/64 x 5/64 x 3/16-inch ring lands. Specific notes for installation and compatibility include: the standard bore size is 3.875 inches, but these pistons are for a 3.905-inch bore. They are designed with an offset pin and are press-fit only. For proper fitment, it is noted to use 4.0 block and rods with a 258ci crank. These pistons are intended for AMC/Jeep 4.6L Inline 6 Cylinder engines with a 3.895-inch crankshaft stroke, 6.123-inch rod length, and a 1.353-inch compression height. The advertised piston weight is 437 grams, with a 170-gram wrist pin.