Universal Fitment Across All Komatsu "Dash" Configurations: Engineered for the co-developed Komatsu SAA6D107E. This cylinder head provides complete casting and accessory hole compatibility across all emission iterations and machine generations, including Tier 3 (Dash-8 excavators, Dash-6 wheel loaders, Dash-22 dozers), Tier 4 Interim (Dash-10 series), and Tier 4 Final / Stage V (Dash-11 excavators, Dash-7/Dash-8 loaders, Dash-24 dozers). Whether your machine utilizes early Cooled EGR or advanced late-model DPF/SCR emission systems, this casting matches original physical footprints exactly.

Eliminate head gasket vulnerabilities and valvetrain fatigue under the absolute most punishing industrial workloads. The Workhorse Plus tier cylinder head for Komatsu SAA6D107E series engines is engineered specifically for severe-duty applications—such as high-impact rock breaking, heavy dozing, deep demolition, and continuous high-load material handling—where equipment breakdown and job site downtime are completely cost-prohibitive. Assembled using a renewed, pressure-tested OEM core and premium internal components, this top-tier cylinder head features extreme-duty structural upgrades to handle maximum cylinder pressures, intense thermal expansion, and continuous peak-torque demands.

Upgrades Over the Workhorse Tier: Heavy-Duty Valve Springs

While the Workhorse tier introduces a critical O-ringed deck, the Workhorse Plus upgrades the entire assembly with premium, heavy-duty valve springs and reinforced retainers. This severe-duty valvetrain package prevents valve float and spring fatigue during prolonged full-load operation, easily managing the extreme cylinder pressures and elevated exhaust backpressures common in modern heavy equipment turbocharger, Cooled EGR, and Tier 4 Final emissions configurations. The result is absolute valvetrain stability and precise tracking when your Komatsu machine is working at maximum capacity.

Components and Parts

• Remanufactured Casting: Built from a premium OEM core casting that has undergone rigorous diagnostic testing and is machined to like-new industrial specifications.

• Precision O-Rings: To combat the severe thermal expansion common in modern high-torque heavy equipment, precision O-rings are machined directly into the deck surface. This mechanical modification locks the head gasket securely in place, completely eliminating the risk of combustion leaks under extreme operating loads.

• New Valves: Equipped with all-new, high-quality intake and exhaust valves, verified for precise seating and clearance against the seats.

Key Features and Heavy-Duty Fixes

This severe-duty head features key structural upgrades, backed by an intense inspection protocol to guarantee every critical industrial metric is met.

• 40 PSI Pressure Testing: Following the machining process, every cylinder head is pressure-tested at 40 PSI to verify zero structural leaks and absolute casting integrity.

• Blow-Proof Plugs: Threaded, blow-proof plugs are installed into the top of the head for superior safety, replacing factory pressed-in freeze plugs that regularly fail during severe thermal spikes.

• Final Quality Control: The head undergoes a meticulous final cleaning and rigorous quality control checking. A comprehensive specification sheet is generated, using a profilometer to record critical specifications including:

  • Valve Recessions

  • Stem Heights

  • Installed Spring Heights

  • Spring Pressures

  • Keeper and Lock Positions

  • Roughness Average (RA) Surface Finish

Recording this rigorous process ensures you receive a head that is significantly improved over the original and ready for years of demanding, heavy industrial operation.

Precision Machining Process

Choate Engineering Performance incorporates structural updates to resolve common factory vulnerabilities of the 6.7L industrial cylinder head, significantly extending operational lifespan:

• Optimal Sealing Surface: The deck is resurfaced to strictly meet or exceed OEM specifications for Roughness Average (Ra), maximizing the sealing surface performance for the head gasket under high common-rail injection pressures and severe thermal stress.

• Valve Train Geometry Alteration: The head is custom blueprinted to adjust valve height and valve recession, optimizing geometry for high-stress industrial applications.

• Lifter and Crosshead Longevity Fix: Valve stem heights are precisely machined to remove excessive preload on the lifters, a critical adjustment that dramatically reduces wear and extends the service life of the bridges, crossheads, lifters, and camshaft under constant heavy hydraulic and engine loads.

• Optimized Flow and Sealing: Valve seats are cut with an industrial three-angle profile to optimize engine efficiency and ensure an airtight seal.

• Valve Prep: Valves are reground and margins are meticulously inspected to guarantee proper sealing against the new seats.

• All-New Wear Parts: New valve stem seals, valve seats, valve guides, and injector cups are installed across the entire assembly.

Meticulous Cleaning and Prep Process

Our manufacturing protocol begins with an intensive cleaning and stress-relieving process to ensure a flawless casting:

• Rigorous Inspection (MPI): Every single core is subjected to Magnetic Particle Inspection (MPI) to scan for microscopic cracks or subsurface structural imperfections common in high-hour castings.

• Thermal Stress Relieving: Castings undergo a thermal baking process in a specialized furnace to eliminate residual industrial oils and grease by converting them to ash.

• Material Relaxation: The head is shot-blasted to strip away rust and scale. This vital step relaxes the cast iron before any precision machining takes place.

• Thread Restoration: All broken factory bolts and studs are professionally removed, leaving all holes clean, chased, and ready for a seamless installation.