Cummins 3021581 Oil Cooler Core

The Cummins 3021581 oil cooler core is a direct-fit replacement component designed for Cummins NT855, N855, and NTA855 series diesel engines, including Small Cam and Big Cam I/II/III configurations. It serves as the core element within the Cummins 3003814 oil cooler assembly. The unit features a tube-and-shell construction with copper alloy tubes for efficient heat transfer. It is engineered to maintain optimal oil temperature under sustained heavy load conditions in highway trucks, construction machinery, marine propulsion, and stationary power generation. Key specifications include a core length of 12.625 inches (320.7 mm) and an outer diameter of 5.00 inches (127 mm). The part weighs approximately 4.75 kg (10.47 lbs). It is manufactured to meet or exceed OEM specifications for pressure resistance, flow capacity, and thermal performance. Compatible with Cummins engine models NT855, NTA855, 855 FFC, and N855. Cross-references include Cummins 208149, 3412285, 3018692, 3045483, and 218754. Aftermarket interchange numbers include Interstate-McBee M-3021581, PAI 141420, AFA A3021581, and AKMI AK-3021581.