5.9L 1989-1993 Cummins Short Block Workhorse Dodge Ram Diesel Crate Engine Choate Performance

The “Workhorse” model is specifically designed for the working man who requires maximum durability and reliability for regular heavy hauling and strenuous towing.

Key Features and Fixes

Upgrades Over the Daily Driver:

• Coated, Fly Cut and Delipped Pistons
• Stage 2 Cam

Core Performance & Power

• High-Output Performance: Rated for 600+ HP capability, delivering significant power over stock for demanding applications.
• Fully Balanced Rotating Assembly: Precision-balanced components ensure smooth, vibration-free operation and extended bearing life at high RPMs.

Reliability & Durability Upgrades

• Upgraded Pistons: Upgraded pistons that are inherently stronger and designed for more robust commercial applications. This solves the OEM issue of weak pistons that are prone to cracking under heat and boost. The Workhorse takes this a step further with Coated, Flycut, and Delipped pistons for maximum thermal resistance and durability.
• Stage 2 Valvetrain & Drivetrain: Equipped with a Stage 2 Camshaft for enhanced strength.

Machining Process:

Choate Engineering Performance doesn’t just rebuild engines - we remanufacture them. Each of our engines undergoes extensive, precision machine work to correct OEM flaws and ensure durability and reliability.

Engine Block Machining:

Each of our engine blocks are CNC blueprint machined using state-of-the-art CNC machines. This process ensures perfect dimensions, precise tolerances, and optimal alignment. This starts with decking the surface of the block to achieve the necessary flatness and smoothness (Ra 30 or better) required for flawless sealing with MLS head gaskets. The cylinders are then diamond honed to an extremely tight tolerance to match the piston diameter (within the nearest 0.0001 inch). Following honing, the main bearing bores are line honed to establish a true, straight centerline for the crankshaft. Finally, the cylinder bores are bored to a true 90 degree angle from the crankshaft centerline.

Rotational Assembly Balancing:

The balancing of the rotational assembly is crucial for eliminating vibration and maximizing engine longevity. This precision work involves checking and correcting the balance of the crankshaft, connecting rods, and pistons. The crankshaft is thoroughly checked for run-out and inspected for fatigue before being polished and ground to strict concentricity tolerances (0.0005 or less) to ensure the new bearings receive the best possible surface. Rods are inspected and conditioned, and all bearing clearances checked to ensure proper fitment with the new bearings. Each of the pistons, rings, and pin retainers are meticulously weight matched (to a tolerance of 2 grams or less) prior to crank balancing. Then the entire assembly is dynamically balanced on specialized equipment. This ensures that the engine runs smoothly, minimizing stress on the bearings, and extends the overall life of the components.

Components and Parts:

Engine Core Components

• Cylinder Block
• Crankshaft
• Steel Connecting Rods
• Stage 2 Camshaft
• Coated, Flycut, & Delipped Pistons
• New Main Bearings
• New Rod Bearings
• New Cam Bearings
• Main Bolts
• Billet Freeze Plugs
• New Oil Pump
• Upper Oil Pan
• Lower Oil Pan

Gaskets and Seals

• Rear Main Seal and Housing
• Front Gear Housing