UL Power Assembly

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Product Overview


  • Reduce lube oil consumption by 50%
  • Eliminate fire face cracking
  • Reduce valve and valve seat wear for improved reliability and performance
  • Minimize gasket failures before overhaul


Progress Rails EMD UL™ power assembly that enhances the reliability of its current power assemblies with new low oil consumption features. Progress Rail has combined its hardened upper bore liner with a specially engineered bore profile, and exclusive ring design, to achieve the lowest oil consumption in the industry.

This proprietary system results in up to 50% savings in engine lube oil consumption compared to standard power assemblies.




Maximum Life Cylinder Head

The UL power assembly includes the new Maximum Life™ cylinder head. The ML™ cylinder head is the most advanced cylinder head produced to date, providing unmatched reliability and durability for the most demanding service.

The new ML head casting builds upon the industry leading Diamond 6™ head with improvements in both coolant flow and structural design. Hardened valve seats provide the most durable valve sealing surface which reduces wear and improves valve sealing.


Flat Head Exhaust Valve

This design improves thermal fatigue life, reduces stresses and deflection, increasing valve and valve seat life. This design also includes a hardened stem tip that extends below the contact area of the keepers resulting in a reduction of dropped valves.


Valve Rotators

Valve rotators induce a controlled spin on the valves to reduce uneven wear on the valve and the valve seat. This improves valve sealing and reduces the occurrence of hard starting.