4.020 Tapered Ring Compressor

The ARP 4.020 Tapered Ring Compressor is a precision engine assembly tool designed for professionals and serious enthusiasts engaged in rebuilding or upgrading piston and ring packages. This tool is essential for tasks such as top-end refreshes, stroker engine builds, or complete long-block assemblies, as it helps prevent costly ring damage during crankshaft installation.

The tapered design specifically accommodates the 4.020-inch bore diameter, making it ideal for modern performance engines, LS platforms, and custom builds that exceed factory stock specifications. It safely compresses piston rings inward as the piston enters the cylinder bore, minimizing the risk of ring breakage or binding against cylinder walls. ARP's precision manufacturing ensures a smooth taper that applies even pressure across all rings without snagging or binding.

Engine builders, machine shops, and weekend warriors tackling serious engine builds will find this compressor indispensable for any platform utilizing a 4.020-inch bore. It is compatible with cast iron, aluminum, and sleeve-equipped cylinders, making it a versatile tool for various engine assembly applications.