Jeep CJ5 CJ7 Scrambler Cherokee AMC 2.5L L4 Remanufactured Engine 1983-1987

Description

Experience dependable low-end crawling torque by installing this Jeep CJ7 2.5L Remanufactured Engine into vintage off-road chassis. This 2.5L 4-Cylinder 8-Valve OHV long block renews mechanical durability on backcountry expeditions. A mandatory trade-off demands immediate verification of mechanical distributor timing and zinc lubricant levels to protect new camshaft lobes from instant heat friction.

Heavy-duty cast iron block casting 3239448 features foundry mark 448 cast on the right side below cylinder number 4. Remanufactured iron cylinder head cores carry casting marks 893, 117, 403, 645, or 684. The complete assembly weighs 254 lbs with crated envelope dimensions of 36in length by 36in width by 36in height. The rotating kit includes crankshaft casting 3239611, forged connecting rods, hypereutectic pistons, and a 4.0-quart oil pan.

Key Features of AMC 2.5L

Mechanics buy AMC 2.5L remanufactured engine assemblies to restore vintage utility vehicles to authentic operating condition. This direct replacement eliminates piston rattle and restores proper compression for off-highway travel.

• Block casting 3239448 receives precision CNC resurfacing to establish Ra 35 surface smoothness
• Plateau-honed cast iron cylinder bores promote oil retention and accelerate piston ring seating
• Crankshaft casting 3239611 is micro-polished to maintain 0.0003in journal concentricity
• Main bearing saddles undergo align-honing to prevent crank binding under heavy vehicle load
• Premium cylinder head gaskets resist thermal expansion and seal high combustion chamber heat
• New pushrods and hydraulic lifters eliminate mechanical valvetrain noise and ensure uniform valve opening
• Cylinder head valve seats receive multi-angle cutting to 0.001in concentricity for clean fuel charge delivery

Dyno Load Precision Machining Tolerances

Every remanufactured engine completes rigorous dyno bench validation to certify 105 HP at 4,800 RPM and 132 ft-lbs torque at 2,800 RPM. Machining specifications mandate crankshaft journal runout below 0.0003in TIR and connecting rod bearing oil clearance of 0.0012in. Cylinder compression gauges read between 150 PSI and 155 PSI across all 4 chambers. Hot engine oil pressure maintains a steady 48 PSI at 2,500 RPM, while regulated coolant operating temperatures stabilize at 195°F to ensure sustained low-speed trail reliability.

Vehicle Fitment Drivetrain Guide

This remanufactured engine fits 1983 to 1987 Jeep CJ5, CJ7, Scrambler CJ8, and Cherokee models powered by the AMC 150 2.5L engine with VIN code U. Designed for 4WD systems coupled to 4-Speed Manual, 5-Speed Manual, or 3-Speed Automatic transmissions. Drivetrain notice: this assembly does not fit 1980 to 1983 GM Iron Duke 2.5L applications, does not fit later EFI Renix configurations, and does not mount to Chevrolet bellhousing patterns.

Installation Protocol Service Schedules

Prime the internal oil passages using an external drill tool to saturate the top end before starting the ignition system. Check carburetor linkage travel and replace aged radiator hoses. Never run this naturally aspirated carbureted engine with high-pressure electric fuel pumps exceeding 5 PSI without installing a dedicated pressure bypass regulator.

• Fill engine with 4.0 quarts of high-zinc SAE 10W-30 break-in oil to shield camshaft lobes
• Drain break-in oil and install a replacement oil filter after the initial 500 miles
• Change motor oil and filter every 3,000 miles to keep pushrod passages clear of debris

Warranty Terms Core Return Policy

We back this remanufactured assembly with an industry-tested 3-Year Unlimited-Mile parts warranty for long-term security. We include prepaid freight service to ship your old core within an authorized 30-day window. Each wooden crate holds the assembled long block, oil pan, valve cover, timing cover, and installation manual.