GM LS FT Piston Set 4.005 Bore -3.3cc

The Race Tec Pistons GM LS FT Piston Set 4.005 Bore -3.3cc is a forged flat-top piston package engineered for GM LS-series engine applications requiring precision bore sizing and negative compression ratios. This eight-piece set delivers the core component quality demanded in high-performance LS engine builds where compression tuning and port-to-piston clearance directly impact combustion efficiency and detonation control.

The 4.005-inch bore specification matches oversized LS blocks, while the -3.3cc dish volume provides a negative compression ratio ideal for forced-induction applications or high-octane tuning strategies where reducing compression prevents detonation. The forged construction resists thermal cycling and high-load stress common in modified LS engines. Ring groove geometry of 1.5 x 1.5 x 3.0 mm accommodates standard LS ring packages and maintains proper ring seal under sustained boost or high RPM operation. Each piston in this eight-piston set carries the dimensional consistency required for balanced firing pressures across all eight cylinders.

This piston set serves LS engine builders working with supercharged or turbocharged platforms, stroker builds, and displacement-increased blocks where compression control is critical. The flat-top design provides straightforward fitment into standard LS heads while supporting increased boost levels. Buyers choosing Race Tec Pistons for GM LS engine builds should verify piston-to-valve clearance and confirm ring end-gap setup with their specific head and cam combination before installation.

LS piston selection hinges on compression ratio, bore diameter, intended boost level, and head gasket thickness. The -3.3cc volume on oversized 4.005-inch bore pistons creates a specific compression point; verifying this matches your target static and dynamic compression is essential for engine durability and performance consistency.