Ford 6.7L Power Stroke Engine Specs, Problems & Reliability

While the majority of current diesel engines use heavy cast iron, the 6.7L Power Stroke has a cylinder block made from compacted graphite iron (CGI). Its deep-skirt block also has nodular iron six-bolt main caps, highly common on the 7.3L Power Stroke instead of the 6.4L's bed plate. This block layout in addition to the CGI material provides significant weight savings over the 6.4L predecessor. The 6.7 Power stroke also features a steel crankshaft, powdered-metal cracked-cap connecting rods made by Mahle, and Federal Mogul cast-aluminum pistons. The connecting rods have an end cap that is rotated 45 degrees to increase strength. The engine was equipped with piston cooling jets for lower piston and combustion temperatures. This affects positively on engine longevity. All 6.7L blocks are manufactured by American foundry company, Tupy.

First for the truck segment, Ford's 6.7L Power Stroke uses cast-aluminum cylinder heads. They feature the reverse-flow design. Each cylinder has for valves (two intake and two exhaust valves; 32 valves total). Every valve is equipped with its own rocker arm and pushrod. The intake air goes through ports inside the valve covers, while the exhaust gases into exhaust manifolds located in the lifter valley (in a traditional V8 engine, the exhaust exits from the outside). In engine valley, there is also a Garrett GT32 DualBoost variable geometry single sequential turbocharger (SST). The exhaust volume of this system is smaller, providing a much more dynamically responsiveness of the engine. The compressed and hot intake air is cooled by a water-to-air intercooler, which is connected to a secondary cooling system of the engine. This powertrain secondary cooling system is also used for cooling of EGR circuit, transmission fluid, and fuel cooler. The primary and powertrain cooling systems have their own water pump, thermostats, degas bottle, and radiator.

The 6.7L Power Stroke is equipped with a high-pressure common rail direct injection. The Bosch CP4.2 fuel pump supplies fuel under a 30,000 psi for the 19 mm piezo actuated Bosch injectors with 8 hole nozzles. The fuel injectors are capable of pulling off five events per combustion cycle.

In 2015, the GT32 SST turbocharger was replaced by the Garrett GT37 with single VGT. The GT37 features a larger 88 mm compressor wheel as well as increased turbine wheel to 72.5 mm, up from 64 mm in the GT32. The fuel system also was upgraded with a higher-flowing Bosh CP4.2 high-pressure fuel pump with a larger stroke and optimized injector nozzles. With made improvements, the engine is able to produce even more power.