aldw

To me this is code for "S-Class competitor? Don't count on it."

I heard "No, we're not going to make 4-door coupes, S-M-L-XL-XXL CUVs/SUVs, X6 fighters, or 5 Series GT fighters." But that could be my optimism flaring up again.

That's closer to the truth than "no S-class fighter."

What about using a gasoline fuel cell replacement for IC engines instead?

Cadillac would be penalized for engine sharing much more than Toyota with, especially since there's a greater perceived difference between a Chevy and Caddy than there is between Toyota and Lexus, and the market acts accordingly. That's one reason why having an extra $1000 charge for engine exclusivity may be necessary to win over the target customers.

On the engine cover thing, definitely agree 100% that GM needs to do much better.

Found one of these a few years ago in a junk yard. The only thing worth saving was the rood as the rest was left to rust beyond saving. We went over it all and it was a shame but nothing was left to save.

How hard would it be to build one from scratch btw?

The Tesla Model S has far more practicality too and is in a way an intriguing prospect. But to get the good range and acceleration you need to option up to the really expensive model. I just don't see a big market for electric luxury cars, let alone luxury coupes. Usually people buy a coupe because it is a fast sports car, not because it is slow and can go 40 miles on electric.

This is also the type of thing that keeps Mercedes and BMW on top, and the rest chasing. Cadillac, Lexus, Lincoln, Acura, whoever all default back to turning a Chevy/Toyota/Ford/Honda into a luxury car and it comes out half baked, because at the end of the day, that ES350 is still a Camry, the MKS still a Taurus, the ELR still a Volt, Escalade a Tahoe, etc. Mercedes and BMW are purpose built for the class on a clean slate, not modified from the parts bin.

Then the Omega should be a winner being purpose built for Cadillac...

Benz has built pushrod engines before, in fact one of their engines was used to win the Indy 500 back in the 90's before it was promptly banned, so it isn't a lack of ability for them to build CIB engines. In the end however, marketing muscle will overpower mere technical ability, from the 1930's to today (just look at Marmon, Duesenburg or Doble for example).

Given that Bentley is giving up the Pushrod for DOHC for future engines, my take is that GM will sooner rather than later be forced to used DOHC for V8s or face market oblivion.

Actually they did use the DOHC configuration for V8 engines. Twice actually. Once in form of the DOHC 5.7 liter V8 in the Corvette ZR1 and once more in form of the Northstar 4.6. They were discontinued because they were generally inferior to the Pushrod alternatives.

As far as "faith" based takes go, one can just as easily assert that "sooner rather than later, the superior performance and economics of Pushrod V8s will force BMW, M-B and everyone else to develop a pushrod engine or face market oblivion.

However, given that they are all using DOHC configurations rather than pushrods and continuing to develop such, empirically DOHC is winning the marketing war far more clearly than pushrods.

Given that Bentley is giving up the Pushrod for DOHC for future engines, my take is that GM will sooner rather than later be forced to used DOHC for V8s or face market oblivion.

The LS and Continental (w/suicide doors) always defined for me the best vehicles of Lincoln, and anything that brings back a modern equivalent can only be a good thing if Lincoln is to survive.

As long as the Alpha CTS keeps the double A-arm front setup I'll be happy...

Why not develop a constant speed diesel mated to an electric transmission system? This would get rid of a lot of combustion issues (since the engine will always be operated at its peak emissions and fuel efficiency level), while eliminate gearing issues with the electric drive system.

The better marketing in this case will be the key determinator in seeing which products win out, of which the TT DOHC V6 has the advantage for all intents and purposes. Technical excellence alone is not enough to win, and the history of the automobile has plenty of examples of such occurrences.

The ability to say that you outperform the competition is a very powerful marketing tool and one that is pretty easy to wield. Sure as hell easier to wield than having to recite the number of valves, turbos or intecooler systems while justifying why you make less power than M3 or C63. Let's put it this way... for the technically inclined audience, the merits of your engine does not need any convincing once you post your power, torque, fuel consumption, weight and/or acceleration times. For the technically challenged, it won't matter if you cite acronyms like DOHC, DI, VVT or IBC. They don't know what these mean nor do they care. To these types of crowd, you simply tailor the add to convey the message that it's a pretty car and it is very fast.

That's assuming all other things being equal, but if the competition is willing to spend more on lightweight alloys and greater refinement to boost overall performance (chassis-wise), extra power alone wouldn't be enough to make the difference, particularly since GM has been shown to be reluctant to spend for the same level of refined quality.

Horsepower to engine weight is not how I would classify an engine as superior. What about noise, vibration, harshness, fuel economy, displacement taxes, CO2 taxes etc. And if the pushrod was the superior valvetrain, why is there no pushrod 4 cylinder and only the Impala/Lucerne have a pushrod V6. GM fans want to say the pushrod V8 is better because it is what they have.

GM thought the pushrod was superior in the 90s with the 3800 V6, then in 2004, the HF V6 came out, GM could have put that into Chevy/Buick/Pontiac, instead, the 3800 soldiered on and 3500 and 3900 V6s were released. In the case of all 3 pushrod V6s, they paled in comparison to what the imports had, the market share loss GM sedans suffered in the 1990s and 2000s was gigantic.

If they put the pushrod V8 in the ATS-V (which wouldn't surprise me), they gain no credibility for being innovative. If I'm buying a V-series Cadillac, I don't want the engine out of a $30k Chevy. It better be special.

Noise, Vibration, Harshness will be no worse than an DOHC powerplant of equivalent displacement. It is only worse because pushrod engines tend to have larger displacement and higher reciprocating mass. But is really not bad at all. If you believe it's bad you probably haven't driven a Vette or CTS-V. Actually, the 3.6 DI V6 sounds harsher and is noisier than a pushrod 3.5 V6 -- really. Fuel economy can actually be equivalent or better. CO2 and displacement taxes do not apply to the USA, and generally does not sway buyers of this category of cars. BTW, a Pushrod V8 is not what I have, but it is what I'll prefer in an ATS-V over a DOHC V8 or a bi-turbo V6. My current cars are a M-B C55 AMG with an SOHC 5.5liter V8, before that it was a Bi-turbo Audi S4.

GM thought the Pushrod was cheap in the 90s. They never strove to make their pushrods state of the art. This has nothing to do with the configuration, it has everything to do with the bean counting mentality.

If they put a Pushrod V8 in the ATS-V it will have a more unique powerplant and better performance than a twin turbo V6. Everybody has a twinturbo, DOHC DI V6. No other luxury compact has a Pushrod V8.

The better marketing in this case will be the key determinator in seeing which products win out, of which the TT DOHC V6 has the advantage for all intents and purposes. Technical excellence alone is not enough to win, and the history of the automobile has plenty of examples of such occurrences.

Link to article

It's speculation at best, and I think they are wrong.

My guess is that the ATS-V will get a Normally Aspirated Pushrod V8. This alone puts differentiates it from the bigger and more expensive CTS-V. The Gen V Direction Injected Pushrods will make about 450~470hp out of 6.2 liters. This is less than the 556 from the LSA, but it'll be adequate to trump the M3 and the C63. The Pushrod V8 will have the additional advantages of being lighter, smaller and cheaper to build. Fuel Economy probably won't be that different and may actually be better since you are not dragging along 32 valves, four camshafts and all their drive parts.

If the choice is between marketing and simplicity for the same level of power, marketing will trump this one.

The MKR and Continental are two must-builds, along with a SL-level Mark IX type coup along with that. The current V-6s would be better than the old iron-block straight-6 though.

The article has some inconsistencies.

(1) There is no way Holden Commodores will be both Epsilon (FWD) and Zeta II (RWD). It is just not practical. They'll either stick to one, or they make one a Commodore and the other an entirely different model with a different styling and a different name.

(2) There is no mention of the Small Block V8 going into the "ultra Lux" Caddy based on the Sixteen concept being DOHC. Honestly, an LS9 or its Gen V equivalent of a supercharged SB V8 is more than good enough with over 630 hp and surprisingly civilized character. The biggest problem will be the transmission. Currently, GM's stoutest 6-speed auto transmission (6L90) is rated for 550 lb-ft of torque and a 6200 rpm max shift speed, ultra lux buyers are not going to want to row a stick. They may have to develop a new transmission, or if the usage is limited to this one model, go outside and buy one -- possibly the 5-speed ZF auto used in the S65 AMG.

GM was supposed to be developing a dry dual-clutch transmission, so something of that sort needs to come out anyways.

:roflmao: :roflmao:

Kind of..but in European version. But sad thing is..here are a lot of people who thinks like that.Like it or not it is reality. These kind of buyers don't know much about engines (and why should they) so they read what car magazines write about it. And thinks that the more expensive the car is that you have higher status in society. And more complicated engine means better . I don't think that in USA is much different. Or am i wrong??

The Luxury vehicle consumers I know think along those very lines, which is why I feel that Cadillac has to take those things into consideration when developing new vehicles, and why having parts like the Ultra V8 or TTV6 is so important also.

I don't think the ATS-V will get the LS engine. I'm fully expecting it to be something like a twin turbo 3.0 or 3.6

For me, if the ATS-V gets a 3.6 TT I would buy one as soon as I possibly could.

Using an intermediate idler to drive the DOHC sprockets on the heads would not be an efficient or convenient way to do it. If not anything because the high placement of the IBC cam sprocket puts it at a very shallow angle to the OHC sprockets making it necessary to introduce two more idlers just to get the chain to wrap around the OHC sprockets enough. Chances are, you'll drive the overhead cams directly from the crank. At least one of the two cams that is, the other can be driven via helical gear or another chain from the first cam.

The IBC accommodations can be used to house a counter-rotating balance shaft if you want to go overboard. A 90 deg V8 is very well balanced with crank weights alone. But, it is not perfectly balanced. There is a bit of residual wobble in the Cg. You can add a counter rotating shaft to further cancel that out for a really serene engine. It'll cost you a bit of complexity and a bit of fuel economy from the extra friction, but the resulting engine may rival an I6 in smoothness.

That's a very interesting concept, if GM were to do that it would be a really sweet engine for a luxury vehicle and be a technical one-up on the Germans.

Seeing the latest comparo between Mustang and Camaro on Road and Track covering the GM and Ford V-8s, they do list the benefits and drawbacks of both, but it also helps clarify why the DOHC engine would be preferable over the pushrod regardless of issues such as head width or parts complexity, especially for the consumer. That's also why reviving the Ultra V-8 would better for Caddy than the Gen 5.

Actually, that may not be the case. Let's put it this way...

There are in general two types of car buyers -- the tech savvy ones and the those that are not.

It is easy to sell technical merit to the tech savvy buyers. Just tell them how your solution is better -- better power to weight, better power to size, better economy, whatever. Most of the time you don't even have to tell them. Bury that marketing in a brochure and they will find it even before your sales guy does.

And then, there are the typical buyer who doesn't even know what DOHC stands for and thinks push rods is something that's part of the door. These types will probably look at the MPG numbers on the stickers and some may go as far as to ask you if it is a "Vee 6". If you tell them it's an I4, they may tell you "Oh, that's cool, just like an iPhone!" But that's about it. They'll go for a test drive, listen for road noise, feel the ride a little and they'll check out the amenitities in the car. How valves are operated in the engine won't come up in the conversation.

For the former, as long as the engine has merit it'll do fine. For the latter, whether an engine has merit or not probably doesn't matter as much as the seat cushions.

There's still the in-between crowd that thinks in terms of HP/L and '4-valves good, 2-valves bad' that is also pretty sizeable and spreads things via word-of-mouth, that's also something that marketing should take into account too.

Well, a few things of note here...

The first being that you can skew things significantly wit the choice of gearing. The 6.2 Small Block turns in 16/25 on an Automatic Camaro SS for instance.

The second being that you are looking at about 60 more horses and two more cylinders on the small block so it is not exactly an apples to apples engine comparison.

Overall, there seems to be a difference in fuel economy between DOHC and Pushrod engines of similar output, cylinder count and/or displacement. And, it seems to favor the Pushrod engines. For instance... the 6.2 liter Gen IV Pushrod turns in significantly better numbers than the Mercedes 6.3 liter DOHC V8 (AMG) or the BMW 4.8 liter (N54) NA engines. Better by about 2~3 mpg in city cycle and 3~5 on the highway. Despite perceptions to the contrary, there is a very good reasoning behind this. The Pushrod layout has less valves, less cam lobes, less cams, less bearing surfaces in the valve train. This in general translate to lower frictional losses. They do not have as much valve area and do not breathe as well at higher RPMs. But, engine breathing has practically nothing to do with fuel economy -- at part throttle and at cruise, the engine is making partial power based on an intentionally reduced amount of air actually being aspirated. Any amount of restriction not presented by the intake and valves, is intentionally created by the throttle plate! Similar pumping losses + higher frictional losses means higher consumption, all else being equal.

Reducing displacement in and of itself also sounds better than it actually helps. A 3.0 V6 in the CTS is no more economical than a 3.6 V6. A 1.4 turbo is only 2MPG better in a 38 MPG car than a 1.8 NA while making the same amount of power (albiet a bit more torque), and only with the help of lower rolling resistance tires. This shouldn't be that surprising either. Think about it, same cylinder count, same # of valves and cams means nearly the same frictional loss save of that associated with the very slightly smaller bore. Hence, the gains in frictional reduction is small to begin with. While the turbo brings additional power to make up for the power loss due to displacement reduction, it also brings with it a reduction in compression ratio which hurts cruise economy.

All in all, if you want to build the most economical engine, you'll want the minimum cylinder count, highest compression ratio, the least number of valves and the smallest number of camshafts that will still give you the required output. There are certain contradictions in this in that big bores and lower cylinder count tends to also hurt the maximum compression ratio you can run with a given fuel octane number. For example, a 3.0 liter I-4 for instance with say 11:1 compression on 91 octane, a single overhead cam and 8 valves will be more economical than a 2.5 V6 with quad cams and 24 valves. Another example will be a 1.8 liter 3-cylinder 2-valve SOHC ought to be more economical than a 1.5 or 1.8 liter 4-cylinder. When the objective is all out economy, Honda went for a 1.0 liter three port with 1 cam and 2-valves per cylinder in the original Insight. This is from a company who championed DOHC and cam switching VTEC on their sport compacts at the same time. On the big end of things, we see that a 6.2 liter V8 with 16-valves and 1 cam can be more economical than a 4.8 liter quad cam 32-valve V8. The question is whether you are willing to live with the increased vibrations of having bigger cylinders and fewer of them.

The persistent thing that's bugging GM is that no matter how good technically a pushrod design may be, it will still cost less to sell a DOHC-engine vehicle than a pushrod equivalent thanks to all the momentum the DOHC designs have been getting over the last 20 years, something that GM doesn't have the money or the time to overcome. This is also why I expect Ford to be able to sell more 5.0 V8 equipped vehicles of whatever type compared to their GM counterparts.

It really comes down to cost vs benefit. A high revving 3.6 can give GM a clearly class leading NA V6. In fact, even the "modest" version with nothing more than a compression bump, camshaft change and tuning for 91 octane will put the 3.6 in the #2 spot amongst "big" V6 class -- trumping the Ford, Hyundai, Toyota and Mitsubishi 3.5~3.7 liter mills, and fall in in just behind Nissan's 330hp CVVL 3.7 liter on power and beating it on torque. It'll do so without incurring the cost and complexity of a twin turbo setup.

A twin turbo DOHC V6 offers good power, but I am not sure it is more economical than a small block pushrod V8 -- not in terms of fuel economy, not in terms of power-to-weight, not in terms of power-to-size and certain not in terms of simplicity. For instance, the SHO's Ecoboost 3.5 makes 350~355 horses and turns in 17/25 mpg with an automatic tranny. A 6.2 liter small block offers 400~426 hp and turns in 16/24 mpg with an automatic tranny in an SS. Granted the SHO is some 300 lbs heavier and AWD. But it also makes 50~76 less horsepower and is basically FWD until the tires slip.

Wrt luxury vehicles the more important issue is having more exclusivity in the product especially the powertrain and not just the power output,

The market expects high tech

Pushrod OHV engines are not precieved as high tech no matter how good they may be.

Try telling a future Caddy owner that he gets to pay twice as much for what is the same engine as in a truck.

I think you get the idea

A luxury car should have the best Tech and the LS is not - its a good engine but its not high tech

GM has invested zero in combating the perception problem OHV engines have.

Unless GM is willing to invest the time and money to change perceptions (which they don't have), DOHC is the only viable route.

I'd still prefer to have a 6-cylinder for the mid-level versions, and I for one wouldn't like to have to purchase a BMW just because someone decided to leave that out.

Fair enough. I didn't expect you to be able to anyway.

The latest issue of Automobile magazine I saw had a nice rendering of the ATS in the preview section, if it turns out like that I would definitely be in line for one.

Yeah...

And the general public also knows that Hyundai was a pile of $h! not even 10 years ago, and that Audis were a death trap when they first came here, and that Toyota's (gasp*) kill people just like other cars, and that Fiat had huge relaibility issues, and that Mini's were unsafe little cracker boxes.

This 'mindset' of "we can't reinvent our brands" seems to only be prevalent in the domestic automaker circle and it is 1) ridiculous and 2) defeatist. Soon we won't have any brands to reinvent if we don't HAVE CONFIDENCE in what the brands truly represent and INFORM the rest of the public that the stereotypes are completely off base and false.

A brand/identity is WHAT YOU MAKE IT. It isn't ASSIGNED to you unless you allow that to happen.

Been saying that for a long time too, seems that the media prefers to box things in simplistic fashion for the unwashed masses to gulp down.