4.155 Tapered Ring Compressor

The ARP 4.155 Tapered Ring Compressor (Part No. 900-1550) is a precision engine assembly tool designed for piston ring installation in 4.155-inch bore engines. This tapered aluminum compressor simplifies ring management during block preparation and engine rebuild, providing controlled compression that prevents ring damage during installation. The black anodized finish protects against corrosion while handling the rigors of machine shop and garage environments.

The tapered design is engineered to compress ring sets uniformly across their full circumference, critical for proper piston seating and ring seal integrity in high-performance and stock rebuild applications. ARP's aluminum construction keeps weight minimal while maintaining rigid structural integrity under compression loads. The compressor accommodates the specific 4.155-inch bore specification, making it a direct fit for engines requiring this exact size—precision that eliminates trial-and-error fitting and potential ring breakage during assembly.

Engine builders, machine shops, and serious enthusiasts performing top-end rebuilds rely on properly sized ring compressors to ensure clean installations without ring set damage or time-consuming adjustments. The 4.155-inch bore size applies to various small-block and mid-displacement engines common in street performance and racing builds. For technicians restoring classic performance platforms or building new race engines, this tool prevents costly mistakes and ensures consistent results across multiple builds. The lightweight design reduces fatigue during repetitive installation work without sacrificing durability.