DEARBORN, MI –Motor Co. isn’t ready to share specific data – power and torque bragging rights are too critical in the heavy-duty pickup sector to let rivals get a look this far in advance, but the auto maker is promising its new homegrown Power Stroke diesel engine easily will surpass the previous generation in performance and efficiency.
A demonstration here of the engine running at idle proves the new 6.7L V-8 also will operate with only a fraction of the outgoing 6.4L Power Stroke V-8’s chatter, shimmy and shake.
Development of the new diesel, which began in 2006 and helped add fuel to a series of disputes with current Power Stroke supplier Navistar International Corp., will culminate with a public showing of the newF-Series Super Duty pickup Sept. 24 at the Texas State Fair.
Slated for production at Ford’s Chihuahua, Mexico, engine plant beginning in the fourth quarter, the diesel is scheduled to hit the market in second-quarter 2010 in the ʼ11 model Ford Super Duty and be available to Ford chassis cab customers.
The new overhead-valve engine, codenamed Scorpion by insiders, weighs about 160 lbs. (73 kg) less than the current Power Stroke, thanks in part to the use of compacted graphite iron for the engine block and aluminum for the cylinder head.
“We use CGI a lot on our European engines, so we have a lot of experience with that,” Adam Gryglak, lead diesel engineer, notes of the first application of the material in a Super Duty-class engine.
The CGI block offers twice the strength of a conventional cast-iron block, which allowed Ford to thin the cylinder walls to lower mass.
The weight-cutting aluminum cylinder head features dual water jackets, both upper and lower, for better cooling and long-term durability. Ford uses six bolts per cylinder, rather than a more conventional 4-bolt setup, for improved sealing.
The 4-valve-per cylinder head employs dual hydraulic lash adjusters, with two pushrods per cylinder, rather than the conventional single-rod design, plus individual rocker arms.
Perhaps the biggest innovation is the engine’s inboard exhaust and outboard intake architecture. Adapted from marine engines, Ford says the new Power Stroke is the first modern automotive production diesel to feature the design that flips around the exhaust manifold to the other side of the engine, cutting in half overall exhaust-system volume, reducing noise and heat and improving performance.
“When you drive this, you will be impressed with the throttle response,” Gryglak promises.
Another industry first is the application of a single-sequential turbocharger from Honeywell International Inc. that incorporates a double-sided compressor wheel mounted on a single shaft. Also unique is the positioning of the turbo low in the back of the valley of the V-8 between the two cylinder heads, a placement that helps keep turbo noise from creeping into the pickup’s cabin.
The new design provides twin-turbocharger-like power in a smaller package that can react more quickly and transition “seamlessly,” Gryglak says.
The common-rail, direct-injection system is new-generation RobertGmbH technology capable of feeding fuel at pressures up to 30,000 psi (2,070 bar). The system delivers up to five injection events per cylinder per cycle using 8-hole piezo injectors. Ford has the system set to two injection events per cylinder per cycle at idle, rather than one, a big contributor to the diesel’s ability to run silent.
In addition to the new turbo, manifold and fuel-injection technology, Ford minimizes noise, vibration and harshness via a composite oil pan and a tuned composite intake system that employs two molded-in resonators (plus a third resonator located elsewhere) tuned to different sound-canceling frequencies. Two acoustic covers on the sides of the engine block high-frequency noise emitted by the injectors.
The diesel utilizes a urea-based selective catalytic-reduction system to limit oxide of nitrogen emissions to tougher new standards set for 2010. Manufacturers must cut NOx output 80% from levels allowed in 2007.
Warranty issues plagued the Navistar Power Stroke, and disputes over which company should foot the bill prompted the lawsuit Ford launched against Navistar in January 2007.
So Ford engineers are quick to point out the new Power Stroke’s rigorous test regimen that included 250,000 miles (402,000 km) in the lab and thousands of hours running while over-boosted and overloaded. Engines were started some 2,600 times at 32º F (0º C), equal to more than seven years of cold starts, and put through a simulated 10 years of use in arctic conditions.
Although Ford won’t be specific about power outputs and fuel economy, Gryglak says the new engine will post “significantly improved” numbers from the outgoing 6.4L’s 350 hp and 650 lb.-ft. (1,013 Nm) of torque.
The first Ford diesel approved to run on B20 biodiesel, the auto maker says it also had to make a number of “material upgrades” to accommodate the fuel, which is growing in popularity, particularly among agricultural customers.
Maintaining the engine has been simplified, with all routine work capable of being performed with the truck cab in place. Time required to service certain components has been cut dramatically, Ford says, with turbocharger maintenance time slashed by 4.5 hours and servicing of the exhaust-gas-recirculation cooler trimmed by 5.2 hours.
Gryglak says Ford decided to bring the next-generation diesel development work in-house because “it was time.”
“We had the resources, and the Super Duty brand is important to us,” he says, revealing the auto maker has 111 patents pending with the new engine.
Ford says it controls about 60% of the commercial-pickup sector. Typically, about 65% of the Super Duty retail market opts for diesel, while only about 30% of more cost-conscious fleet buyers do.
About 40% of those buying a Ford diesel do so for personal use, the auto maker says, with about 20% commercial-use customers and the remaining 40% a combination of the two.
Although volumes typically have ranged from 175,000-275,000 annually over the years, the recent economic slump has taken its toll on the market in the past year. Ford says it has sold 45,000 trucks equipped with Power Stroke engines through the first eight months of 2009.
Ford will have capacity for 200,000-plus of the new diesel, Doug Scott, director-truck marketing says, noting forecasters are predicting a near recovery in the fullsize pickup market to about 2 million units (still down from a peak of about 2.5 million) in 2015.
Meanwhile, Ford officials say the prospects for a diesel in the light-duty pickup market remain dim, as long as fuel costs remain low and the pump price for diesel remain near that of gasoline.
Ford earlier pulled the plug on plans for a light-duty diesel application for 2010.
“We’re monitoring (the market),” Scott says, adding Ford would need considerable time to bring a diesel to the sector, even though some development work already had been done with an eye toward the 2010 launch.
“A lot has changed,” he says. “It might not be as quick as all that.”