ARP 901-8500 Billet Aluminum Piston Ring Compressor

The ARP 901-8500 is a precision-engineered piston ring compressor designed for professional engine builders and serious enthusiasts. CNC-machined from 6061-T6 billet aluminum tube material, this tool features a true radius design that ensures smooth, damage-free piston installation into cylinder bores.

Key Features:

• CNC-machined from high-strength 6061-T6 billet aluminum for exceptional durability
• True radius design matches bore diameter precisely, unlike conventional tapered compressors
• Relieved bottom edge accommodates wire O-rings without interference
• Type 3 hard anodized finish for superior wear resistance and long service life
• Bore size prominently engraved in 3/4-inch high numbers for quick identification
• Professional-grade construction eliminates risk of ring breakage during installation

The true radius design of this ARP ring compressor provides uniform compression around the entire piston ring pack, significantly reducing the risk of ring damage compared to traditional tapered sleeve designs. The precision machining ensures consistent bore diameter throughout the length of the tool, making piston installation faster and safer. Available in bore sizes ranging from 3.552 to 4.750 inches for SAE applications, and 75mm to 95.5mm for metric applications. Widely recognized by professional engine builders as the premium choice for piston installation.