12 replies to this topic

[Top Fuel F1]

Re: Posted PDF on desmo's Sticky Thread:

http://www.atlasf1.c...&threadid=28541

The W12 architecture used for the Paper, when looking at it from the front, is a "V" with a verticle line ( "l" ) raising in the middle of the "V". Another analogy would be demonstrated by spreading your fore finger, index finger and ring finger apart. Another thought would be that it's like a 3 cylinder segement of a 4 bank radial engine. In other words it's not a true "W" configuration. Not to be confused, the author(s) use the word "bank" in a different way than it applies to a radial engine. They call each row of of 4 cylinders, from the front of the engine to the rear, a bank. In any event the W12 architecture used in the Paper has two major problems: (1) With the center bank sticking straight up in the air, you can not realize the minimum height for a W12, (2) With this center bank stuck in the center of the V formed by the two other banks, you create a critical exhaust/ventilation problem. In all fairness this Paper was presented in Nov. 1998 and it was not until July 1999 that the second generation VW VR6 was realized. However the authors base the credability of the W12 design they used for the Paper on the W12 engine architecture used for Audi's AVUS concept car. Meanwhile, the fact is that Audi had spent years researhing the very W12 architecture proposed for the AVUS 4; but it never became workable because they never solved the exhaust/ventilation problems for the center bank of cylinders without wasting too much space or overheating the surrounding areas.

Mean while two of the 2nd generation VR6 cylinder blocks can be put together to form a W12 engine. If you just set two VR6 engine blocks together on the floor, the configuration forms a true "W". However the two blocks, which each have an asymetrical arrangement of (a 3 cyl. row) and (3 cyl. row) at about a 15 degree angle, are joined around a single crank at what can be about an included angle of 70 to 90 degrees from block to block. True it is now no longer a true "W" configuration; but that's what they continue to call it. At this point you can realize a configuration with the best opportunity for lowering the engines height. As well the exhaust/ventilation problem is solved, in that all induction enters from the Top/Middle of the engine and all the exhaust exists from the bottom of each side of the engine.

The Paper concluded favorably (W12 Vs V12 and more so over the V10) while using the discarded Audi W12 architecture. If the current combined VR6 (2nd gen.) design had been applied it would have been lower and a 1/2 cylinder longer; but still shorter than either a V12 or a V10. In any event I believe the conclusion of the Paper would still have favored the W12. However it would also have been based on a design that has proven workable on a practical basis.

[Zoe]

Unfortunately I forgot the details, but the Volkswagen VR6 engine is reported to have major problems; probably due to vibration and also thermal issues aren't as peachy as printed on those glossy Volkswagen prospectus.

Anyone know more about this specific item?

Zoe

[Top Fuel F1]

Originally posted by Zoe
Unfortunately I forgot the details, but the Volkswagen VR6 engine is reported to have major problems

The VR6 is a 12 valve, 2.8 liter DOHC 6 cylinder motor which came to the United States in 1992. The unique VR6, or "VEE Reinhenmotor" is technically a V6, but its two rows of three cylinders are only 15 degrees apart. This narrow angle allows it to have only one cylinder head, which makes it similar to a straight 6.
Whether it is a true DOHC motor is of some debate. It does indeed employ 2 camshafts, which is what Dual OverHead Camshaft implies. However, the VR6's camshafts are intake AND exhaust combined, but one for each row of cylinders. A true DOHC V6 uses 4 cams, one for intake and one for exhaust on each cylinder bank.
The VR6 delivers 174 hp and about 180 Ft. Lbs. of torque in stock form. The new 24V VR6 may deliver 204 hp, and should be on the market soon. This 4 valve per cylinder engine is the second generation VR6 I was talking about in the first Post. I don't know if they have been having trouble with the current 2 valve per cylinder engines; but they sure have a lot of them installed in a lot of different models. If that is the case, I suspect some one else on the BB would have heard about it. Not to mention that VW would be in a lot of trouble.

[Melbourne Park]

Top Fuel the VW would still be a V6 though. Lancia used to do that, with the narrow angles, on most of their 4 and but not their six cylinder engines, and they were always referred to as V engines ...

[Top Fuel F1]

Originally posted by Melbourne Park
Top Fuel the VW would still be a V6 though. Lancia used to do that, with the narrow angles, on most of their 4 and but not their six cylinder engines, and they were always referred to as V engines ...

Melbourne Park:

Please take a look at this:

http://www.fortuneci...e_packaging.htm

Also the new (planned) Bugatti with a W16 is basically using the same engine scheme as the W12 (comprised of two VR6 blocks). Although they don't commercially exist, that would amount to a engine comprised of two VR8s. I agree that once combining the two V blocks it is not necessarily an absolute W shape; but also it's certainlly no longer a V. In the end we'll have to go along with what the majority is referring to these as. So far you can see from the article, that although being made up from two Vs, they are going to refer to these as Ws.

Rgds;

[Melbourne Park]

Thanks TopFuel, thats good stuff. In fact, just the same as Lancia did years ago. Great site on the VW efforts.

I looked up a Lancia book, and regarding the site's reference to the " breakthrough achieved by Volkswagen in 1991, Lancia did it somewhat before that: 65 years in fact. The first monocoque car, the Lancia Lambda, had the same narrow angle single block idea - including the Asymmetric Configuration - engine configuration in its four cylinder back then!! Then the Dilambda had a short V 8 cylinder 4 litre engine. They were a bit different back then though: they were push rod, with the rods going through the centre of the block. The Dilambda also had independant suspension all round ... It also had the Lancia sliding pillar suspension, which was a McPherson strut with the spring at the bottom of the shocker rather than at the top. By 1932 the Lancia found a solution to its somewhat rough but compact and powerfull engine in a way later much copied:

but in the mounting of the engine in the frame a very great departure for Lancia has made, in that the unit is held flexibly at four points in rubber and coil spring bearers, there being, in addition, laminated springs running for and aft between each pair of mountings

. This mounting made the engine feel like a six it was so smooth. Well before fluid filled engine mounts!

By 1932 Lancia had converted to overhead cams for their narrow angle V engines. This arrangement carried on with 4 cylinder Lancias into the mid 70's Fulvias, when taken over by Fiat. Lancia had dropped the idea for the first front drive cars, which used water cooled boxer 4s, there was still a boxer four front drive Lancia coupe, the Thema I think, available in the 80s.

A description of one of the smaller fours, a little over one litre, says that it had 10 degree 14 minute V4.

The block is only 9 and a half inches long from front to back. A single csting in light alloy forms the cylinder head and carries the inlet valves on the right side and the exhaust valves on the left side

. Essentially the same Asymmetric Configuration. But time ran out, and Lancia never developed the four valve version of VW.

I've always had a soft spot for Lancia. Just after I married, my wife almost bought a beautifull Lancia Flavia Coupe. It was made by Pininfarina, and even had the same tachometer and speedo nacelle as the Daytona. She didn't buy it I think because besides fear of getting parts, she stalled it three times in row on a steep hill when trying to do a turn into heavy oncoming traffic. That car had the boxer four front wheel drive engine. Now Subaru copied that from Lancia, and many Subaru cars now have a device that holds the car on a steep road without using the hand brake... Ah ... poor old Lancia, they didn't deserve to be gobbled up by the conventional Fiat group...

[byrkus]

True, I always considered Lancia as a sort of Italian Citroën... Both had advanced technology, radical ideas, controversial bodyshapes... I just gope, that the new Thesis will bring Lancia back to its former glory.

[david_martin]

Originally posted by Zoe
Unfortunately I forgot the details, but the Volkswagen VR6 engine is reported to have major problems; probably due to vibration and also thermal issues aren't as peachy as printed on those glossy Volkswagen prospectus.

Anyone know more about this specific item?

Zoe

Actually I think that was the now shelved VR4 project, which was intended to be the basis of the next generation "mid-capacity" VAG engines. The other new engine that formed part of that programme, an inline 3 which will slowly replace all of VAG's small gasoline engines, has just made its debut in the new Polo.

[ray b]

V
^
or
X





but motor is a X not a W

[Top Fuel F1]

If you haven't already seen this on the plans for the new Bugatti (when I previously Posted this in another Thread), they too are also depicting the combination of two "VR" type engine blocks into a "W16" engine configuration:

http://www.vwvortex....tti/index.shtml

[Zoe]

Originally posted by david_martin
Actually I think that was the now shelved VR4 project, which was intended to be the basis of the next generation "mid-capacity" VAG engines. The other new engine that formed part of that programme, an inline 3 which will slowly replace all of VAG's small gasoline engines, has just made its debut in the new Polo.

I dunno. There are quite a few fatal engine problems reported from very new Volkswagens. Problem is, that the average Volkswagen owner doesn't know which type of engine is in there, so I am still trying to figure out which engine is most affected and what was the reason for the failure.

The VR6 does have some vibration due to the 15 degree Vee, but in practice they shouldn't cause major problems.

At least the Volkswagen engine do not seem to be as bad as the Opels ;)

Zoe

[Top Fuel F1]

Unfortunately this picture is not labeled:

http://home.uni-one....evue16/16-7.jpg

However at the top and from this angle I can count eight ducts. Also block bank appears to be very heafty. So I assume it's a W16.

[Top Fuel F1]

The Bugatti with the W16 seems a little way out; but this car with a W12 looks closer at hand:

http://www.cardesign...swagen-w12.html