Home » 2011 Lincoln MKX: another use of the 3.7 Ti-VCT DOHC V-6

2011 Lincoln MKX: another use of the 3.7 Ti-VCT DOHC V-6

by DrivingEnthusiast

We’ve seen the spy pics for months, now the production vehicel has been announced. This isn’t a vehicle for a Driving Enthusiast of any sort… and it isn’t meant to be unless your definition of Driving Enthusiast is a nice ride in a very carefully conditioned environment.

What’s important here is that this is yet another user of the new Ti-VCT 3.7 liter DOHC V-6, previously shown in the Mustang. And what’s notable is that despite the transverse mounting, the engine stil makes the full 305 HP and 280 ft-lb torque. This helps pay the bill for the use of the engine in the Mustang. This same engine has been spotted in spy pictures of the upcoming all-new Explorer as well (putting to rest another site’s claims that the Explorer wil be “all EcoBoost”).

What interesting is the technical discussion of Atkinson Cycle, the inclusion of fuel shutoff during deceleration, and some other fuel saving strategies. as Mazen Hammoud says, every component is optimized, as well as the operaiton of those components together.

Ford Press Release follows:
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2011 LINCOLN MKX EMPLOYS ARRAY OF TECHNOLOGIES, INCREASING HORSEPOWER, MAINTAINING FUEL ECONOMY

  • The 2011 Lincoln MKX boasts best-in-class horsepower and torque versus all V-6 competitors with unsurpassed fuel economy
  • The new 3.7-liter Duratec® V-6 engine employs several fuel-efficient strategies that also improve performance, including Twin Independent Variable Camshaft Timing (Ti-VCT), aggressive deceleration fuel shutoff and Smart Charging
  • Engineers applied lessons learned from Ford hybrid vehicles to the powertrain development of the 2011 Lincoln MKX

DETROIT, Jan. 12, 2010 – The 2011 Lincoln MKX, with industry-first MyLincoln Touch™ driver connect technology, is a high-tech showcase. That is true of the luxury crossover’s powertrain as well.

Its new 3.7-liter Duratec V-6 employs advanced technology and clever control strategies to increase horsepower and torque to best-in-class levels while achieving unsurpassed fuel economy.

“Fuel economy continues to be at the top of customers’ minds,” said Greg Johnson, Lincoln powertrain manager. “But customers refuse to compromise on power. With the 2011 Lincoln MKX, they won’t have to. We’re delivering increased power and torque with unsurpassed fuel economy.”

2011 Lincoln MKX customers will enjoy a luxury crossover that delivers best-in-class power and torque versus all V-6 competitors with unsurpassed highway fuel economy of 25 mpg – all on regular fuel. Horsepower has been increased to 305 – a 15 percent increase compared with the outgoing product – while torque is up to 280 ft.-lb., marking a 12 percent improvement.

The 3.7-liter V-6 is mated to a six-speed SelectShift Automatic™ transmission, which gives customers the option of a fun-to-shift manual experience.

In SelectShift mode, the transmission doesn’t second-guess the driver, offering total control over gear selection and performance feel. Upshifts, for instance, are not commanded at redline, and downshifts are allowed at the lowest gear possible as defined by the engine speed.

“When the system is in manual mode, engine speed matching provides faster and smoother downshifts, and the customer gets the gear they request within the limits of the rev limiter,” said Johnson.

When a lower gear is selected while descending a long downhill grade, the 2011 Lincoln MKX in SelectShift mode will hold that gear until the driver manually upshifts or returns to the fully automatic setting. To ensure safe shifting, the transmission will downshift to the lowest acceptable gear, based on a calculated maximum speed. That means if a vehicle were traveling at highway speeds, the driver could not downshift to first gear in SelectShift mode.

Improvements to engine hardware as well as the powertrain control strategies account for the gains in power and fuel economy. Here’s a closer look at how the 2011 Lincoln MKX delivers increased power without compromising fuel economy:

Twin Independent Variable Camshaft Timing (Ti-VCT)

What it is: Ti-VCT technology creates precise, variable timing control of both the intake and exhaust camshafts, which control the valve opening and closing events. Each of the four camshafts is controlled independently. Ti-VCT uses the intake camshaft phasing to advance the intake valve opening and the exhaust camshaft phasing to retard the exhaust valve closing. Ford’s unique strategy involves using a mild Atkinson cycle during part-throttle operation for fuel economy improvement. 

The Atkinson cycle: The Atkinson cycle is similar to the familiar four-stroke cycle – intake, compression, combustion and exhaust – except the intake valve closes well after the piston begins moving upward to compress the air-fuel mixture.

There are two key benefits of the Atkinson cycle. First, it reduces the “pumping losses” associated with all gasoline engines. Additionally, because a fraction of the air-fuel mixture is released from the cylinder back into the induction system without being burned, the effective displacement of the engine is reduced. The power stroke, or the distance that burning fuel pushes on the piston, is longer than the effective intake stroke. This helps extract more energy from each drop of fuel. The Atkinson cycle is employed in Ford’s hybrid lineup, contributing to the unsurpassed fuel economy of both the Fusion and Escape Hybrids.

How it helps: The ability to vary the overlap between the intake and exhaust valves helps eliminate compromises in the two processes. The result is greater efficiency, which leads to better fuel economy – approximately 3 to 4 percent improvement from this strategy alone compared to non-VCT engines. Another benefit of Ti-VCT technology is a broadened torque curve. Because the Ti-VCT strategy allows the intake valve to be advanced, instant power is delivered when the customer demands it. Approximately a 10 percent power improvement is enabled by this strategy compared with non-VCT engines.

Aggressive Deceleration Fuel Shut-Off; torque-based deceleration control

What it is: A control strategy that shuts off the engine when the customer doesn’t command engine torque, which helps save fuel. A typical maneuver when this comes into play is during deceleration at freeway speeds when in fifth or sixth gear. The fuel flow seamlessly resumes when the vehicle reaches a low speed or when the driver accelerates again. All other powertrain, braking and electrical systems continue to function normally while the fuel delivery is stopped.

How it helps: The system uses the torque delivered to the transmission to keep the engine running at a low, more efficient point whenever possible, using the momentum generated rather than more fuel to keep the vehicle moving.

Battery management: “Smart Charging”

What it is: A system that allows the battery to be charged or discharged at optimal opportunities instead of allowing the alternator to continuously charge the battery independent of customer use, which wastes energy.

Smart Charging increases the alternator output when the vehicle brakes or decelerates, converting the vehicle’s kinetic (motion) energy into electric energy without having to use additional fuel.

How it helps: The “free” electric current is used to recharge the battery so that it can be used by the electrical systems later. This could be when the engine is switched off during a stop or when the generator is operating in a less efficient mode. The battery’s advanced management system continually monitors its status and communicates with Ford’s Aggressive Deceleration Fuel Shut-Off system so the regenerative charging feature can charge the battery in the optimal way. The decel system knows how much battery charge is available so that it can leave the engine running if the battery does not have a sufficient level of charge.

Longer battery life, reliable starts: Smart Charging improves the life of the battery because it keeps the battery at a more consistent level of charge, which in turn aids in reliable starting. The one-touch starting in the 2011 Lincoln MKX enables starts of around seven-tenths of a second with precise fuel delivery for maximum fuel economy and minimal emissions.

Engine hardware improvements

What was added or changed: Piston-cooling jets, polished valvetrain buckets, improved intake manifold and cylinder head port flow.

How they help: The piston-cooling jets spray oil on the underside of the pistons and enable faster oil warm-up and a higher compression ratio; the polished valvetrain buckets reduce friction, which in turn aids fuel economy and also improves durability (wear) of the cam and bucket tappet; the improved intake manifold and cylinder head optimizes engine “breathing,” contributing to overall system efficiency.

“The key to the performance gains and fuel economy with the 2011 Lincoln MKX is that we don’t look at power and fuel economy as being mutually exclusive,” said Mazen Hammoud, Lincoln powertrain calibrations manager. “Instead, we focus on optimizing every component, every system and every control in the powertrain for greater efficiency overall, which enables increased power, better performance and response and helps to maintain the fuel economy found in smaller-displacement engines.”

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