Wednesday, November 02, 2005

Volkswagen Narrow-Angle V6

Text from Volkswagen of America.
LAS VEGAS, Nov. 1, 2005 – To Vee or not to Vee. That was the question Volkswagen powertain designers asked themselves when they sat down to design the next-generation engine in the late 1980s. Throwing out preconceived notions and traditional thinking, these innovative German engineers focused on the “best” solution, not necessarily the most conventional solution.

What was the problem? VW needed an engine, larger and more powerful than the current range of inline 4- and 5-cylinders, to install in future Volkswagen models. A 6-cylinder was the logical choice, but which type? An inline six has the advantages of a single cylinder head, narrow width and excellent balance. But the length made it impractical for transverse installation in front-wheel-drive vehicles unless VW was considering something as wide as a semi-truck.

Why not a V6 to take advantage of this engine’s short overall length and compactness? Conventional V6s typically have an angle between the cylinder heads of 60 or 90 degrees. Sixty degrees is preferred because it results in optimal balance. We all know that optimal balance is achieved in a V8 when the banks are 90 degrees apart. But lop off two cylinders for a 90-degrree V6, and you create a vibration problem that requires balance shafts to remedy.

For VW, neither of these conventional V6 designs was an option. The width of a V6 would have required lengthening the vehicles for which it was intended to provide enough crumple zones between the front of the vehicle and the engine and between the engine and the passenger cell, allowing VW to meet current and future front-end crash standards.

This is when conventional logic gave way to out-of-the-box thinking. The result: an engine with all the advantages of both a V6 and an inline 6-cylinder with none of the disadvantages. Voilá, the VR6 design, which literally comes from the combination of Vee and the German word Reihenmotor. The combination of the two can be roughly translated as “inline vee.”

VW designers created a 15-degree V6 that is narrow, short and compact with excellent balance and requiring only one cylinder head. All of these attributes make it ideal for tuning. And the new-generation V6 introduced in 2005 takes the concept one step further with an even more compact 10.5-degree angle between the banks.

And like its predecessor, this latest VW masterpiece of engine engineering has the right stuff to spin the crank to high revs for increased output. Major components are a cast-iron crankcase, an aluminum crossflow cylinder head for better breathing and a drop-forged crankshaft that runs in seven main bearings. There are two overhead camshafts, one for each bank of cylinders. And the camshafts are operated by a rugged two-stage chain-driven assembly, not by a rubber belt. How durable are these chains? They are also used with the diesel version of this V6!

Designers placed a lot of emphasis on proper engine cooling. The water pump housing is cast integral with the engine crankcase, not bolted on. In addition to the belt-driven water pump, the V6 engines use an auxiliary electric pump to circulate water while the engine is running and during the cooling fan after-run cycle. Circulating the coolant during this time helps cool the engine block and prevent the possibility of air pockets forming in the cylinder head. In addition, V6 engines also use an oil-to-water heat exchanger to aid engine warming from cold start-up and to maintain proper oil temperature during driving.

The crossflow cylinder head has allowed the use of a single exhaust manifold rather than a manifold for each bank. This helps control under-hood engine temperatures by placing a hot exhaust manifold on only one side of the engine compartment.

The V6 not only helps satisfy strict safety requirements by fitting transversely in VW’s front-drive vehicles, the narrow-angle architecture delivers the smooth revs of an inline six and a torque-rich powerband. These are just two of the reasons why the V6 is a favorite with some of the world’s top aftermarket tuners, such as Marcel Horn of HPA.

An acknowledged expert on VW models, Horn said, “The VR6 design is the best kept secret in the VW arsenal. It is simply a bullet-proof motor, brilliantly simple in its design, which delivers the best torque-to-horsepower ratio across product lines.”

“Some call this a very stout, durable, well-designed powerplant,” Horn continued. “Every VW with this configuration will be competitive in power for comparable vehicles.”

The V6 should be especially interesting to the SEMA community, as this engine is an outstanding basis for drag racing and road racing when fitted with either turbocharging or supercharging.

Except for a select few, much of the speed industry has neglected to give Volkswagen’s narrow-angle V6 its proper due. Now with a new, more powerful 3.6-liter V6 that has arrived in the 2006 Passat, it’s time that Volkswagen opens the throttle and roars the news about an engine that deserves more than quiet respect.

Founded in 1955, Volkswagen of America, Inc. is headquartered in Auburn Hills, Michigan. It is a subsidiary of Volkswagen AG, headquartered in Wolfsburg, Germany. Volkswagen is one of the world’s largest producers of passenger cars and Europe’s largest automaker. Volkswagen of America and its affiliates employ approximately 3,000 people in the United States and are responsible for the sale and service of Audi, Bentley, and Volkswagen products through retail networks comprising in total more than 900 independent U.S. dealers.

"Volkswagen" and "4MOTION" are registered trademarks of Volkswagen AG. "DSG" is a trademark of Volkswagen AG. All other trademarks used in this document are the property of their respective owners.

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