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BorgWarner expanding variable cam timing technology for I4 engines; OEM diesel and gasoline applications in 2015

New cam phaser for I4 engine. Click to enlarge.

BorgWarner is expanding its variable cam timing (VCT) technology with a new family of cam phasers for inline-4 engines. The modular design supports a variety of cam phasing technologies, including cam torque actuated (CTA) and torsional assist (TA) phasers with optional mid-position lock technology. (Earlier post.) Each phaser also features an integrated center bolt and spool valve for smaller package size and easier installation.

The technology is planned to launch with a major global automaker on diesel and gasoline applications in 2015. Both will be supported by production at a new facility in Eastern Europe. The new facility complements a number of existing global facilities producing VCT technology.

By allowing the camshaft to be phased relative to the crankshaft while the engine is running, VCT gives the engine designer added flexibility over a conventional fixed timing drive system.

Using the existing torsional energy in the valve train, CTA phasers actuate more quickly, use less engine oil and operate under a wider range of engine speeds and temperatures than conventional VCT systems. TA phasers, which use torsional energy and standard engine oil pressure to actuate the phaser, offer a wide range of authority, achieving 70 degrees of crank rotation or more.

BorgWarner phasers can actuate rapidly, resulting in improved low-end engine performance in downsized, direct-injected boosted engines.

For added calibration opportunities, BorgWarner’s patented mid-position lock technology allows an increased range of camshaft positioning with a default stop at an intermediate position within the expanded range of travel. The built-in failsafe ensures the phaser returns to the middle position for reliable engine starts in nearly any potential operating condition. All phasers also feature an integrated center bolt and spool valve, resulting in a compact design that has fewer parts and is easy to install.

I4 engines have captured about 75 percent of the global engine market and are forecast to power over 17 million additional vehicles in the next seven years. Our new cam phasing technology is engineered to offer automakers customized, fast-to-market VCT solutions to support increasing demand for efficient, downsized engines.

—Joe Fadool, President and General Manager, BorgWarner Morse TEC



Is this basically the technology needed to make a variable-compression ICE, kind of making the engine be both a regular engine or an Atkinson engine depending on the cam control?


I do not know if any of these ubiquitous VVT systems include late (or early) intake valve closing to reduce the intake charge with less throttling (Atkinson).

More to the point, have the newer systems been able to do both jobs - maximize torque over the speed range and shorten the effective intake stroke(Atkinson)?


"More to the point, have the newer systems been able to do both jobs - maximize torque over the speed range and shorten the effective intake stroke(Atkinson)? "

The system would have to do each to the exclusion of the other;

- maximize torque when power is needed,

- lower the intake charge when lower power is needed for idle, cruise, etc


I don't understand the statement " the I4 engine is used in 75% of global engines" , but estimate only seventeen million more in next seven years.


I assume you there should be MANY MORE than seventeen million ?

They do say "over" seventeen million more ...


This just appears to be an improvemnet of the conventional cam phaser. To take full advatage of the Atkinson cycle (or the Miller system), you need a more advanced fully-variable valve actuation.


Are the electrically actuated phasers that cost prohibitive? While these improvements are all good, they seem to be inferior to the electric versions, such as those employed by Mazda in their Sky-active family of engines. I believe they can phase up to 180 degrees, provide faster response and even adjust before the engine is running. You would think the next jump for everyone would be to this type of setup.

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