• Shorter airflow from the exhaust system to the turbocharger sitting between the engine’s cylinder banks improves turbo responsiveness.

• Positioning the turbo inside the engine’s valley helps isolate the engine’s hottest temperatures, improving performance and efficiency, while also reducing noise, vibration and harshness.

Ford engineers built upon the benefits of this design as they upgraded the Power Stroke. One improvement is a larger GT37 turbocharger that replaces the previous GT32 model, enabling more airflow to the engine to produce more power beyond today’s 400 horsepower (298 kW) and 800 lb-ft (1,085 N·m) of torque.

GT37 turbo. The GT37 features a single, larger 88-millimeter compressor wheel that replaces the GT32’s dual-sided compressor design. The compressor forces air into the engine’s cylinders to improve performance—especially at high altitude where the air is thinner than at sea level. The turbine size is increased to 72.5 millimeters from 64 millimeters, so exhaust gases have a larger surface area to spin the turbo, providing extra power. The wastegate and the wastegate controls are eliminated, because the turbo operates at lower peak pressures than the GT32.

The original designers of the current Power Stroke V8 diesel forecasted needs for higher output. This facilitated the larger turbocharger, increasing airflow and creating more power. We’ve dramatically improved performance while reducing overall engine complexity by focusing on the turbo system

—David Ives, Power Stroke technical specialist

A further benefit of the larger turbo is improved engine exhaust braking, manually controlled by a push-button switch on the dashboard. Extra braking power helps reduce wear and tear on wheel brakes and requires less manual brake application from the driver, especially on downhill grades.

Fuel system improvements. Turbo changes drove improvements to the fuel delivery system, specifically a new high-pressure fuel pump and fuel injectors. The pump’s cam stroke is increased to deliver more fuel when desired for increased power. All-new injector tips better atomize the fuel, resulting in improved combustion that enables lower noise, vibration and harshness. Other benefits include cleaner emissions and a reduction in the buildup of fuel deposits on the valves over time.

In addition, a new exhaust temperature sensor enables more accurate fuel control, which improves both durability and driveability—especially when towing.

Even though the fuel system delivers extra fuel as needed to provide more power, other efficiency improvements enable the 2015 Ford F-Series Super Duty pickup to deliver performance comparable to today’s best-in-class fuel economy, according to Ford.

Further enhancements to Ford Power Stroke diesel include:

• Ford-designed and -engineered 6R140 TorqShift six-speed transmission uses a new torque converter to manage increased horsepower and torque

• New polymer coating on main bearings for improved wear-and-tear durability and lower friction

• Improved crankshaft fillet design—the transition point between the crankshaft’s journals—to increase crankshaft power carrying capability

• Increased crankshaft damper weight to reduce rotating forces on the crankshaft when the engine is performing at peak power levels

• New five-layer head gasket to handle wider range of engine firing pressures resulting from more powerful engine performance

• Added material to the engine’s cylinder heads, exhaust manifold and valvetrain to handle increased power levels

• Redesigned turbo oil and cooling lines to improve sealing

• Piston assembly upgrades to increase load-bearing capability

• New four-layer exhaust manifold gasket for improved durability

Gen1 Power Stroke hits 500,000 mark. Ford also announced that the 500,000^th first generation 6.7-liter Power Stroke V8 turbo diesel engine was installed into a new 2014 Ford Super Duty F-350 Lariat at Kentucky Truck Plant.

Other benefits of the 6.7-liter Power Stroke V8 turbocharged diesel engine include:

• Compacted graphite iron engine. Stronger than cast iron, the block structure is optimized for reduced weight and maximum strength to meet the demands of higher horsepower and torque

• The advanced inboard exhaust and outboard intake architecture reduces overall exhaust system volume, which leads to better throttle and turbo response for the customer; additionally, reduced exhaust system surface area minimizes heat transfer to the engine compartment and improves noise, vibration and harshness performance

• Engine architecture enables easier service work for all major engine components, potentially reducing downtime

• Turbocharger is uniquely center-mounted on a pedestal low in the back of the valley for improved NVH control

• High-pressure fuel system injects fuel at more than 29,000 psi. The system delivers up to five injection events per cylinder per cycle, using eight-hole piezo injectors to spray fuel into the piston bowl. The direct-injection system is calibrated and phased for optimum power, fuel efficiency and NVH performance

• Aluminum cylinder heads for reduced weight; the mid-deck construction with dual water jackets provides increased strength and optimal cooling; six-head bolts, instead of four as found on other engines, help improve sealing and maintain cylinder integrity

• Compatible up to B20 biodiesel