W

[targa]

I've got lots of questions, this one is, what is a W engine? on the Road and Track-Road test Summary, the Bently Continental(sp?) and the VW Passat W8 have W engines instead of V. The Bently has a W12 and the Passat has a W8. What is this W?

[Sweeney921]

the W stands for the arrangement of the cylinders. While a V engine has 2 banks (rows of cylinders), a W engine has 4. It's like having 2 V engines combined. A W12 engine would have 4 banks of 3 cylinders, a W16 engine would have 4 banks of 4 cylinders, etc. The advantage of a W engine is you can have a lot of cylinders, but the engine is very compact. However, they seem to be prone to overheating, and desinging an oiling system for them is extremely complicated.

This link has a short description of the Bugatti Veyron's W16 engine:
http://auto.howstuffworks.com/bugatti2.htm

[Mustang]

a W12 is basically 2 V6's together side by side.

so the coniguration is something like this \/\/ instead of \/

[Coventrysucks]

so the coniguration is something like this \/\/ instead of \/

Not really, as they both run from the same crank.

Imagine it as a V but each side of the V is a narrow angle V engine.

So for the Passat it has two narrow angle V4s, the Phaeton, Touareg and Bentley have two narrow angle V6s (as in the VW VR6 engine), and the Veryunlikely is two narrow angle V8s.

[deffenbaugh03]

so does it look something like this \||/ except with the two lines in the middle closer together?

[KnifeEdge_2K1]

Not really, as they both run from the same crank.

Imagine it as a V but each side of the V is a narrow angle V engine.

So for the Passat it has two narrow angle V4s, the Phaeton, Touareg and Bentley have two narrow angle V6s (as in the VW VR6 engine), and the Veryunlikely is two narrow angle V8s.

itll be like this

o o
o_\/_o where the "o" is top dead center for each cylinder in the cross section

one thing though, are all 3 angles identicle? or are they litterally 2 v6s sharing one crank?

[Sweeney921]

yes, it's basically 2 Vs together. the angle in the middle is almost always the biggest, and the other 2 are the same.

[Egg Nog]

I did not write this, but it will be very helpful...

---------------

The W12 engine shown in the mid-engined W12 supercar is virtually a combination of two VR6s. This is confirmed by its 5.6-litre displacement. It is constructed by mating two 15° VR6 in an inclined angle of 72°. In fact it is the earliest VR engine having 4-valves head, although this car was never put into production.

The only short-coming of W-engines is that they require very thin connecting rods, as the crankshaft is much shorter than V-engines. While VR6 uses con-rods with 20mm thickness, the W-engines run with 13mm ones. This prevent it from becoming racing engines. Tight cylinder heads may also limit its breathing and ventilation.

[Coventrysucks]

Here's a little diagram of a W12 I knocked up quickly.

Hope you can understand it. (Its in perspective btw.)

[henk4]

Here is a picture of a Lancia Appia V4 engine, which gives you an idea how a narrow angle (13deg) engine works. You see that the ignition is in the centre of the V, while the carbs are on one side and the exhaust on the other. Now for the W concept you have to imagine that you put two of these engines together on ine crank, whereby of course the flow of the gasses will be inverted, to have the carbs in the middle and the exhausts both to the sides.

[RacingManiac]

It is really the fact that VW makes their VR-series of engine that enables them to make the W motor. As in the 15 degree VR6s already needs only one cylinder head enabling a compact packaging of a 6 cylinder motor in a confined space, in a W8 or W12 the same thing applies, you can stuff a W12 engine in a space only meant for a V8.....

albeit in Conti GT, the sparkplug change can only be accomplished by removing the engine from the confined engine bay.....it boggles the mind...

[targa]

i had the part where there were 2 V sections, in a W layout, what i was really asking was, why, how is that practicle(sp?)?

[Matra et Alpine]

i had the part where there were 2 V sections, in a W layout, what i was really asking was, why, how is that practicle(sp?)?

Hopfeully the pictures from egg-nog and tyhe drawing from coventry has helped.

What may not be obviosu is that it is a single crank.
All 12 pistons are connected to one crankshaft ( see egg-nogs middle picture )
It's no different a 'challenge' to producing a V12, just different timing ( and more compact )

Now the Matra U8 is another matter and covered elsewhere on UCP. IT used 2 cranks connected together !!!!!!!!!!!!!!

[Coventrysucks]

Now the Matra U8 is another matter and covered elsewhere on UCP. IT used 2 cranks connected together !!!!!!!!!!!!!!

And the BRM H16, sounds like fun...

[Matra et Alpine]

And the BRM H16, sounds like fun...

Yeah it was even crazier than Matra's attempt.
Taking two straight 8s and linking them was a mad idea and never worked out.
Heard it on a 5.1 DVD and it is AWESOME.
Wish I'd seen/heard it in real life