August 25, 2011, Bellevue, Washington — Overdrive Magazine’s golden anniversary edition recently named the PACCAR MX Engine one of the Top 50 truck industry technical innovations in the last 50 years. The publication highlighted that the engine was the first in the market to incorporate compacted graphite iron (CGI) in both the block and head, as well as fractured cap technology in the rod and main bearing caps. Fractured cap technology gives the connecting rod and main bearings much more rigid mountings, allowing more torque at a lower rpm. The result is wider torque and power curves for higher operating efficiency.
 

The single in-block, rear-driven camshaft supplies fuel via unit injector pumps. The latter, in combination with short, high-pressure fuel lines and injection nozzles in the cylinder head, is able to produce injection performance comparable with other systems in spite of the simpler camshaft layout. It does this by utilizing electronic control valves both at the pumps and at the injection nozzles and coordinating their functions with the engine control module.