90.00mm Ring Compressor

The ARP 90.00mm Ring Compressor (part number 901-9000) is an essential tool for serious engine builders and mechanics performing piston and ring installation specifically on engines with a 90mm bore diameter. This tool is mandatory for assembling short blocks, as it safely compresses piston rings flush with the piston crown, allowing for smooth insertion into the cylinder bore without damaging the delicate ring ends.

Constructed from precision-machined hardened steel, the ARP ring compressor maintains dimensional accuracy across countless builds, ensuring consistent ring compression without binding or slipping during installation. Its tapered design accommodates factory and aftermarket piston ring sets, adapting to compression and oil control rings without the need for multiple tools or adapters.

Professional engine builders and experienced DIY enthusiasts who work on Honda, Toyota, Nissan, and domestic compact platforms will find this 90mm compressor indispensable for reducing assembly time while protecting expensive internals. Weighing just 0.79 lbs, it is easy to store and handle during engine assembly.