Mercedes-Benz Says Auf Wiedersehen To V12 Engines

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I might be wrong but wern't some of the V12s turbocharged anyway like the SL65 AMG?, I didn't know BMW were changing thier engines either, does anyone know when this will happen?.
 
BMW made a modular engine design with the E60 M5. It could be cut down for a 4 litre V8 (as they did) for the M3. Why not make a 3 litre V6 with it with 300bhp. Then tie it to a properly lightened car.

I would imagine it might have something to do with smoothness and V angles. BMW are known for the engine making (and they keep winning engine of the year with multiple engines in multiple categories, so it's a fair assessment) and they're known for their inline 6's in particular.

Smoothness is supposed to be a big thing for BMW, and just about the only engine smoother than an I6 is a V12. V8's can do quite well, but V6's require a lot of balancing to get right[1].

The V10 in the M5 uses a 90 degree V angle (ie the angle between the two halves of the engine). afaik, there is some disagreement about the ideal V angle for a V10. 72 degrees I've heard being a ver popular one, but 90 isn't too bad either. the great thing about using 90 degrees is that it matches the ideal V angle for the V8 engine, and BMW have been making V8's for a long time.

as you say, this leads well to a modular design where you can reuse a lot of the tooling to make both the V10 M engine, the V8 M engine, and probably the other V8 engines too.

however, 90 degrees is not a good angle for V6's. you can make 90 degree V6's but they have to have wierd split pins on the camshaft and generate nasty end to end vibration which is not what BMW want at all.

besides, as they are committed to rear wheel drive, they don't have a huge incentive to want V6's. they don't need to mount the engine transversely, so engine length is not a big problem (I used to drive a volvo S80 which was one of the very few cars to use a inline 6 engine mounted transversely to drive the front wheels. apparently it also needed the worlds shortest production gearbox to fit in the engine bay).

BMW have an awful lot of experience making inlin 6's and I don't see them stopping anytime soon, in fact I can sooner see them abandoning the V8's and V10's for better I6's.

sorry if I got boring there, but there you go. ll of the above may be rubbish of course, anyone who knows better, feel free to butt in and correct me :)

dave

[1] I am not an engine designer, all this comes from my hazy knowledge of engine design piced up form reading the web
 
Then tie it to a properly lightened car.

genuine question. can a modern consumer saloon car be light anymore?

I mean stripped out racers are one thing (lotus elise, I'm looking at you) but looking at even a fast medium size car, say BMW M3, C63 AMG, Audi RS4 etc. can they ever be much less than 1500 kg's?

for one, they've got great huge engine lumps a the front, then complicated gearboxes and transmissions and differentials to get all that power down.

then there's all the safety equipment, crumple zones, strengthening bars, airbags. there's satnav, screens, great big leather, heated, electrically movable seats. nice quality interior materials etcetc.

all this stuff is expected and if a modern top of the range car didn't have this stuff, it would get panned for it. even then they are sticking carbon fibre roof's and panels on, aluminium this and monocoque that.

so with all that understood, are modern, usable cars going to get any lighter? History shows us that cars get bigger and heavier as time goes on. I'm not sure I see this trend changing...?

dave
 
genuine question. can a modern consumer saloon car be light anymore?

I mean stripped out racers are one thing (lotus elise, I'm looking at you) but looking at even a fast medium size car, say BMW M3, C63 AMG, Audi RS4 etc. can they ever be much less than 1500 kg's?



dave

Yes, if you remove the fancy sound systems, the electical bucket seats and fix manual adjustment seats, and all the luxuries that come on the standard cars. Think of the 911 GT3 approach, and I bet it could be done.
 
Is this story even true? It seems Zonda will still get their supply of AMG V12s and aren't Mercedes are looking to share Cosworth V12 technology with Aston?
 
Yes, if you remove the fancy sound systems, the electical bucket seats and fix manual adjustment seats, and all the luxuries that come on the standard cars. Think of the 911 GT3 approach, and I bet it could be done.

according to parkers:

a 911 GT3 still weighs 1395kgs

a standard carrera weighs in as.. 1395kgs (doesn't sound right, unless the gt3's lightening is t counterbalance some other heavy extra?)

the heaviest 911 (okay, I guessed, but a carrera 4 tiptronic sounded likely) is 1490kgs, so still only 95kgs more than the GT3.

but bear in mind, I said a modern consumer saloon, and you picked a stripped out racer. a stripped out racer is allowed to forgo rear seats for scaffolding and not have a stereo.

however, the public have certain expectations of the level of trim in a top of the range saloon car/coupe, and not fitting a good stereo or electric seats won't cut it.

hence my point, are cars practically ever going to get lighter again?
 
Some intersting points, but I would hazard a guess here that wherever Mercedes builds its engines, won't be doing V12's.

I can imagine however, that AMG, or even Brabus will still make then. Or the Cosworth tie up might be the way forward. Mercedes don't do small scale, but they can outsouce the work.

And Rolls Royce are about to release a Baby rolls, that apparently should shift 3000 a year, with a V12.
 
[1] I am not an engine designer, all this comes from my hazy knowledge of engine design piced up form reading the web

That all sounded about right, flat horizontally opposed engines are the smothest but in line 6 is next best and V engines are used for balance and packaging as flat engines need a lot of width.

As you said, 90 deg for an 8 cyl, 60 deg for a 6 cyl, 72 deg for a 10 cyl.

Different angles cost a lot in tooling so manufacturers stick with 90 deg and fit balancer shafts for the 6 cylinder engines, which is not ideal but works to a point.

My guess as to why V12 are being phased out is cost against volume sold and emissions requirements.
A 12 cylinder engine of modular design uses 50% more fuel to overcome friction as opposed to an 8 cylinder.
 
Its still very nose heavy however.

Completely aside and unrelated to this thread I know BMW will go the turbo route with the M cars. This IIRC is a shame, those that have had a BMW on here, will recall how nice the N/A engines were on full song. Why not make the cars lighter instead, and that doesn;t just mean some carbon fibre on the dash.

well, that didn't take long... not just one bit of heresy, but two! a turbo-charged M engine... in an SUV?

X6 M prototype video

dave
 
My guess as to why V12 are being phased out is cost against volume sold and emissions requirements.
A 12 cylinder engine of modular design uses 50% more fuel to overcome friction as opposed to an 8 cylinder.

Well, Audi continue to introduce new models with V12 power. The last being the Q7 and soon the R8.
This is a very nice engine animation

http://uk.youtube.com/watch?v=eeUXOXo-lRw
 
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The voice is spreading Mercedes will begin phasing out V12 engines


“Mercedes-Benz, longtime stalwarts of the V12 engine, is considering lowering its preferred cylinder count by a third. While our first inclination is to assume that this change is being made to increase the fuel efficiency and lower the emissions of the overall Daimler line, the real reason that the bent-12 engine program is being dropped is simply because the block is too long. A V12 is, for all intents and purposes, the same length as an inline-six, and the German automaker's latest line of mainstream engines are all in a V-design, so its cars are no longer being designed with an engine compartment large enough to house such a lengthy engine. Fear not, power fans, as the company isn't abandoning high horsepower in general. The V12 program is apparently being shifted towards twin-turbo V8s, and the magic of forced-induction means there's no reason to assume that fewer cylinders will equal fewer ponies. Expect the moratorium on V12s to begin the next few years.”
 
With a little bit of Brabus help the V12 will fit in the E, CLS and C class. It's not that big.

Very true!!!

I am considering this conversion with a Brabus 7.3L V12 on a W124 500E :eek: :rolleyes:

BRABUSV12.jpg
 
There's certainly packaging advantages in a W12 format over a V12. The VAG W12 in the Bentley comes as something of a shock when you see it in real life, it's so short.
The piston format of the W16 in the Bug is neatly shown in this video

http://uk.youtube.com/watch?v=ziDh6...E8127747E&index=8&playnext=2&playnext_from=PL

The disadvantage is the W16 noise is rather agricultural.
I always thought the VAG units with their narrow V angles were almost like an inline 6 in overall length?
They are engineered like a straight 6 so have a single cylinderhead, 7 main bearings and individual crank throws for each piston. The engine itself is more of a stagerred inline 6 than a true vee engine from an engineering perspective.
The W12 will be similar, built essentially of two banks of narrow angle VR6's but a larger conventional vee angle between the two banks of 6 (if that makes sense:D ), so in overall length isn't all that much shorter than a traditional V12.
 
I always thought the VAG units with their narrow V angles were almost like an inline 6 in overall length?
They are engineered like a straight 6 so have a single cylinderhead, 7 main bearings and individual crank throws for each piston. The engine itself is more of a stagerred inline 6 than a true vee engine from an engineering perspective.
The W12 will be similar, built essentially of two banks of narrow angle VR6's but a larger conventional vee angle between the two banks of 6 (if that makes sense:D ), so in overall length isn't all that much shorter than a traditional V12.

I always thought this was quite a good website for picking up car design theory:

AutoZine Technical School

dave
 
I always thought the VAG units with their narrow V angles were almost like an inline 6 in overall length?
They are engineered like a straight 6 so have a single cylinderhead, 7 main bearings and individual crank throws for each piston. The engine itself is more of a stagerred inline 6 than a true vee engine from an engineering perspective.
The W12 will be similar, built essentially of two banks of narrow angle VR6's but a larger conventional vee angle between the two banks of 6 (if that makes sense:D ), so in overall length isn't all that much shorter than a traditional V12.

Er...no, in theory a W12 is one bore width longer than a compact V6 assuming all other things being equal.

6d5ca7d3.jpg
 
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