Chicago Auto Show: 2008 Pontiac G8

[aloofman]

Which, ill have you know is based on the Renault 17 (Or at least the early Lancers were), again, designed in Europe.

This confirms what I knew all along. There are a lot of bad car designers in Europe too!

Are you apart of this group?

http://www.autoblog.com/2007/02/08/suicide-prevention-group-tells-gm-to-pull-robot-ad/

Seriously, I know people were going to be offended by the ad. You can't avoid it with ads like these. But, I can't stand how this country has become so politically correct.

No, I'm not. And I don't see how it's a matter of political correctness at all. I just think it's a strange, misguided ad. If I were one of the thousands of auto workers who have been laid off in the last few years -- many of whom have had their positions replaced by robots -- I would be irked at the idea that it would be a joke to GM. I suspect it was supposed to a bit of self-deprecation, GM making a joke to emphasize their quality-control improvements. But I don't see how the commercial they came up with does that.

And actually, you can "avoid it with ads like these". None of the other car ads could be construed that way. And I think that Snickers ad was funny, but for the opposite reason than they intended: it points out how lame homophobia is instead of reveling in it.

 

[Superdrive]

The Crown Vic platform was around before the guy who designed the Sable was born. Slight exaggeration, but only just. The Sable is a unibody midsize sedan with a FWD V6 drivetrain. The Corwn Vic is a full size sedan with a detuned version of the Mustang V8, ladder frame and weighs two tons. Totally different cars.

The Sable, Taurus, Impala, Camry, Accord and Bonnevile are all much smaller than the Crown Vic. The ladder chassis gives them the ruggedness of a truck, whuch is why cops and taki drivers use them.

Exactly right. The Ford Panther platform which currently lives as the Crown Vic, Grand Marquis, and Town Car feature body on frame construction and a live rear axle. These things are what make these cars the flagship sedans what they are. Ford has not made any public commitment to its Panther beyond 2010 and GM hasn't used its B/D bodies since 1996. Hopefully, this style won't be left upon the wayside.

 

[MacNut]

The Crown Vic platform was around before the guy who designed the Sable was born. Slight exaggeration, but only just. The Sable is a unibody midsize sedan with a FWD V6 drivetrain. The Corwn Vic is a full size sedan with a detuned version of the Mustang V8, ladder frame and weighs two tons. Totally different cars.

The Sable, Taurus, Impala, Camry, Accord and Bonnevile are all much smaller than the Crown Vic. The ladder chassis gives them the ruggedness of a truck, whuch is why cops and taki drivers use them.

My mistake, I was thinking the Grand Marquis when I said Sable. I don't understand why GM dropped the full size car, I think they are a better ride.

 

[quagmire]

No, I'm not. And I don't see how it's a matter of political correctness at all. I just think it's a strange, misguided ad. If I were one of the thousands of auto workers who have been laid off in the last few years -- many of whom have had their positions replaced by robots -- I would be irked at the idea that it would be a joke to GM. I suspect it was supposed to a bit of self-deprecation, GM making a joke to emphasize their quality-control improvements. But I don't see how the commercial they came up with does that.

It isn't a joke to GM. GM is shrinking. They can not support the work force they used to have. So they have to layoff people. I feel bad for the families, but GM had to do it to stay alive. Robots are more efficient then humans and make less errors which thus increases the quality of the car. If you couldn't see why the robot was fired for, then I am sorry. The robot dropped a bolt. GM can't tolerate even as small of a mistake as that( in real life I am sure GM wouldn't fire a person over a dropped bolt). So the robot was fired due to it not doing its job right and risked the quality of GM vehicles. It was in no way trying to make fun of the people that were laid off.

So no one can make an ad of a person getting fired because it will offend people that were fired and laid off by companies( even the company that is doing the same)? That is the thing that urks me and what I meant about the whole PC thing. That America has to avoid offending people and thus take away some of our freedom of speech because it offends someone( like saying black instead of African American).

 

[aloofman]

It isn't a joke to GM. GM is shrinking. They can not support the work force they used to have. So they have to layoff people. I feel bad for the families, but GM had to do it to stay alive. Robots are more efficient then humans and make less errors which thus increases the quality of the car. If you couldn't see why the robot was fired for, then I am sorry. The robot dropped a bolt. GM can't tolerate even as small of a mistake as that( in real life I am sure GM wouldn't fire a person over a dropped bolt). So the robot was fired due to it not doing its job right and risked the quality of GM vehicles. It was in no way trying to make fun of the people that were laid off.

You're missing my point. I'm not saying that GM didn't need to get more efficient, or that the layoffs weren't necessary, or that I didn't understand why the robot was fired in the ad. Robots don't get fired. They replaced human jobs because they can be more efficient and they don't need to be hired, trained OR fired at all. I also didn't say that GM was trying to make fun of laid-off auto workers. I said that interpretation could have been foreseen before the ad aired and they didn't think of it. It was a sloppy, badly-conceived ad that just might sum up how lame GM is these days.

So no one can make an ad of a person getting fired because it will offend people that were fired and laid off by companies( even the company that is doing the same)? That is the thing that urks me and what I meant about the whole PC thing. That America has to avoid offending people and thus take away some of our freedom of speech because it offends someone( like saying black instead of African American).

I didn't say any of that either, it was just what you wanted to respond to. I don't see how appearing needlessly insensitive to the workers you already fired is the same as being PC. It's bad public relations. Steve Jobs once bragged that as CEO he only got paid a dollar a year or something, and now he's embroiled in a stock options investigation. That's not PC either, it's bad public relations, and somewhat ironic.

Anyway, I shouldn't have thrown in that bit that caused this digression. We were talking about bland designs and GM's branding issues.

 

[Counterfit]

You guys do know it was a fan-directed ad, right?

they are great in snow and if Im in a crash I have some protection.

Hmm, sounds like my car.

 

[mojohanna]

Old people. Seriously, the surveys indicate their average driver is in their mid-60s or older.





Since the Crown Vic sells better, maybe it's the Sable that's the clone. (Not that it matters.) My grandmother had a Crown Vic that I drove numerous times. It was solid, comfortable and had some giddyup, but ride and handling were terrible, like trying to park a boat at a pier. It's not a bad car, just not a style that's popular anymore.

The crown vic is ford the gran marquis is its clone from Mercury. The sable is a taurus clone.

The only reason the crown vic is still around is for old people who cant afford a Buick or a Caddy and police departments. That is why GM killed off the Caprice.

Beaten to it...........

 

[iGav]

Oh my, seems my somewhat lighthearted, tounge in cheek comments appear to have provoked some consternation in the ranks.

There is nothing wrong with the OHV design.

Indeed. It's just not as good as the DOHC.

Two things:

A) The ICE is archaic itself.

But one form of it, is more archaic than the other.

B) OHC is actually older then OHV.

Oh come on, age has nothing to do with it, and it was obvious that I was using the word archaic not as a definition of age, but of being old fashioned. There is a distinction to be made.

I will take a 7.0 V8 making 505 HP over a 5.0 V10 making 500 HP. Two less cylinders needed.

Two less cylinders indeed, just an extra 2 litres required to make up the difference in power. That really does sound like the stereotypical 'Because bigger is better, an American Tradition' lazy arsed approach to building an engine.

But your statement above, really does highlight the main problem with OHV engines, that to produce comparable power, a significant increase in displacement is required, which is a detrimental characteristic in some countries.

So, I'd like to ask you a question in relation to your statement.

Would you still take a 7.0 V8 OHV making 505BHP over a 7.0 V8 DOHC making 707BHP? Equal displacement. Equal number of cylinders.

Let alone DOHC V8's of smaller displacement is actually physically bigger then the LS7. Let alone the LS7 is pretty fuel efficient. Hell, GM's OHV V8's are one of the most fuel efficient V8's. Then there is the 3 valve design coming and Direct Injection possibly as well.

Don't forget efficiency depends greatly on the what the engine is installed in.

The only car I know of (off the top of my head) that is currently for sale in the UK, that uses a GM V8 is the Monaro, which uses the 6 litre V8 (LS2 I believe) which is the engine I do believe I (lightheartedly) called into question in the first place.

It does compare reasonably favourably in comparison to Audi's 4.2 litre V8 FSI engine that I also defined as a benchmark engine. Other than it's not as efficient, produces less power, more torque but over a narrower band and more CO2 emissions than the equivalent V8 from Ingolstadt.

Obviously it's not a completely fair comparison, we should consider that Audi's V8 is installed in a Quattro drivetrain, and the subsequent loss in efficiency that that particular arrangement suffers from.

As I said there is nothing wrong with OHV engines.

...back in the 1960's.

Ehhhh, I see you are just one of those guys that just loves HP.

Oh please.

Anyway, as Quagmire mentioned in his earlier post, if you really wanna measure performance of an engine forget the displacement and the number of cylinders and just go with amount of horsepower/torque produced per actual weight of the engine.

Absolute nonsense, and one that is of course going to favour an engine that has to have a significantly higher displacement to be comparable to it's rival configuration. Take comparable engines, of similar displacement, and number of cylinders and the pendulum swings more favourably in the direction of the DOHC.

Anyway... lighten up people, if you love a small block V8, so be it... in the grand scheme of things it really doesn't matter.

G

 

[blitzkrieg79]

Absolute nonsense, and one that is of course going to favour an engine that has to have a significantly higher displacement to be comparable to it's rival configuration. Take comparable engines, of similar displacement, and number of cylinders and the pendulum swings more favourably in the direction of the DOHC.

Anyway... lighten up people, if you love a small block V8, so be it... in the grand scheme of things it really doesn't matter.

Difference between SOHC (usually 2 valves per cylinder although Mitsubishi engines have 4 valves) engines and DOHC (mostly 4 valves) is obviously in their name, one has a single cam and the other has a dual cam setup. SOHC engines are lighter than DOHC engines simply because the extra head weights more. SOHC also has a much better low end pull (makes more sense in daily stop and go driving traffic conditions and in real off-roading). DOHC has a better high end power and generally the same engine but instead of SOHC has a DOHC setup will generate greater horsepower (DOHC is better for sport performance, high speed).

http://paultan.org/archives/2005/06/22/sohc-vs-dohc-valvetrains/

Anyway, you can't ignore the weight of an engine, even Motor Trend this days has a statistic that shows HP per weight of an engine. Car is not just made up of an engine. The heavier the car the more HP/torque it needs to get it moving. Look at Lotus Elise, it has a small displacement engine yet because the entire construction of the car is light the car can compete with supercars that have a lot bigger engines but they also have a lot more weight on them.

The Corvette LS2 engine 7.0 V8 is over 75 pounds lighter than the smaller displacement BMW 5.0 V10. Higher displacement also means less stress for the engine. You cant ignore that. Otherwise you just don't know what you are talking about. Small displacement engines may be good for Europeans or other high agglomeration areas but in US the distances are really high and the lack of public transportation isn't helping much. It's not quite unusual to see 3 year old cars with 100K miles on them. In Europe it would take 7-8 years to do so. Americans simply drive more because they don't have much of a choice.

 

[Superdrive]

The crown vic is ford the gran marquis is its clone from Mercury. The sable is a taurus clone.

The only reason the crown vic is still around is for old people who cant afford a Buick or a Caddy and police departments. That is why GM killed off the Caprice.

Beaten to it...........

I'm not too sure about that reasoning. If the Crown Victoria was around only for fleet vehicles, why would Ford happen to have three vehicles in its lineup that are on the same platform as the Crown Victoria? Right now, you can not find a car in any lineup besides Ford's that compares to the size and design of these Panthers. I hardly believe the GM B/D bodies were killed off because old people preferred the Ford. Perhaps, our environmentally friendly driven economy lead to the demise of GM's rear-wheel drive vehicles. The removal of the Fleetwoods, Roadmasters, and Caprice Classics was a mistake just like the Camaro.

 

[aloofman]

Anyway, you can't ignore the weight of an engine, even Motor Trend this days has a statistic that shows HP per weight of an engine. Car is not just made up of an engine. The heavier the car the more HP/torque it needs to get it moving. Look at Lotus Elise, it has a small displacement engine yet because the entire construction of the car is light the car can compete with supercars that have a lot bigger engines but they also have a lot more weight on them.

So is it power per lb. of engine? Or power per lb. of car? Seems like the latter has more impact on performance.

The Corvette LS2 engine 7.0 V8 is over 75 pounds lighter than the smaller displacement BMW 5.0 V10. Higher displacement also means less stress for the engine. You cant ignore that. Otherwise you just don't know what you are talking about. Small displacement engines may be good for Europeans or other high agglomeration areas but in US the distances are really high and the lack of public transportation isn't helping much. It's not quite unusual to see 3 year old cars with 100K miles on them. In Europe it would take 7-8 years to do so. Americans simply drive more because they don't have much of a choice.

What does more displacement have to do with driving farther? If anything, driving that much more should make you want a more efficient engine, not a bigger one.

 

[Lord Blackadder]

Small displacement engines may be good for Europeans or other high agglomeration areas but in US the distances are really high and the lack of public transportation isn't helping much. It's not quite unusual to see 3 year old cars with 100K miles on them. In Europe it would take 7-8 years to do so. Americans simply drive more because they don't have much of a choice.

I don't know if I believe that. I've been doing a lot of 800+ mile trips lately in my Nissan Altima, with its cast-iron block 2.4L 16v twincam 4 cyl, and it has no problems whatsoever racking up the miles. A good friend of mine has an Integra GSR with a 1.8L twincam in which he does almost 50k miles per year and it runs like a top - AND I can personally vouch for the fact that it is a faster car than most V6 (and some V8) American sedans and coupes. My roomate drove from Death Valley all the way to upper peninsula Michigan in a ratty old Geo Metro with a 1.3L four-banger.

As for stress...big, lazy V8s are less "stressed" in that they usually spin slower and have more metal in them, but I think that the Japanese have more than proven that small, more "highly stressed" engines like the SR20DET or B16/B18 series can be as reliable as you could want. Beyond replacing the timing belt, the internals can go hundreds of thousands of miles with no overhauls.

Big American engines like the Ford 4.6L in the Mustang and Crown Vic are also very reliable and pretty smooth-revving, especially in DOHC form, but I wouldn't say they're more reliable than most of the Japanese engines - they're about the same. My family used to have a Crown Vic, and it had an SOHC version of the 4.6L with 200hp and 250lb-ft. It went almost 200k miles with no trouble.

 

[iGav]

Blah blah blah.... one has a single cam and the other has a dual cam setup.... blah blah blah.

Thanks for pointing that out. I didn't know that. Really.

Anyway, you can't ignore the weight of an engine,

I'm not saying ignore the weight of the engine, but your statement that 'if you really want to measure performance' is completely disingenuous.

Because it's not the only way of measuring perfomance, and it's not the most important, less so when comparing engines that are not materially equal, and that obviously specifically favours one layouts advantage over the other.

The problem you could have with that statement 'as the way to measure performance', is that it potentially falls apart if you compare the 2 engines, with the same displacement and number and configuration of cylinders. I have no doubt that you'll ignore this because it potentially weighs against OHV engines in comparison to DOHC.

The Corvette LS2 engine 7.0 V8 is over 75 pounds lighter than the smaller displacement BMW 5.0 V10.

Can you not see the glaring problem in comparing those 2 engines in the way you're doing?

It'd be much more fair, to compare the 7.0 V8 LS2 engine with a 7.0 litre V8 DOHC, which would be capable of putting out somewhere in the region of 707BHP (though if you used Ferrari's 4.3 litre V8, you'd be nearer 800BHP), and not be vastly heavier than the LS2 (unless it's completely made of cast iron ) I suspect that the power-to-weight of that engine, would be superior to that of the LS2.

Higher displacement also means less stress for the engine. You cant ignore that. Otherwise you just don't know what you are talking about.

I've never suggested otherwise.

Small displacement engines may be good for Europeans or other high agglomeration areas but in US the distances are really high and the lack of public transportation isn't helping much. It's not quite unusual to see 3 year old cars with 100K miles on them. In Europe it would take 7-8 years to do so. Americans simply drive more because they don't have much of a choice.

You don't have to drive everywhere at 8k/RPM you know.

And personally I wouldn't consider either a 4.2 or a 5.0 as "small displacement".

Okay... let me put this to you. If the fabled pushrod is the better engine. Then why is it now considered such a niche design? and why are all the other car manufacturers around the world not aware of this oversight?

 

[blitzkrieg79]

So is it power per lb. of engine? Or power per lb. of car? Seems like the latter has more impact on performance.

Actually both are co-related to each other. Let say you have the same exact car with same exact frame, same options, same weight (minus the engine). One of them has a Corvettes V8 engine and the other has a BMW V10 engine, guess which one will have a better 0-60 time?

What does more displacement have to do with driving farther? If anything, driving that much more should make you want a more efficient engine, not a bigger one.

Less stress on the engine means better engine reliability. Have you ever drove a 4 cylinder car lets say 10 hours straight in a 85-90F weather? Engine starts to get louder and louder, of course people don't realize it because they get used to the constant increase of engine noise but it's a proven fact. Efficiency is another thing as it also is a combination of things. How come you don't see 4 cylinder 1.8l engines in over 4000lb SUVs? Again, it's all about engine stress and reliability as well as performance and not everyone wants to drive a Pinto sized vehicles, some have large families, some just simply want to drive in a comfort which usually means bigger vehicles (more weight).

I'm not saying ignore the weight of the engine, but your statement that 'if you really want to measure performance' is completely disingenuous.

Because it's not the only way of measuring perfomance, and it's not the most important, less so when comparing engines that are not materially equal, and that obviously specifically favours one layouts advantage over the other.

The problem you could have with that statement 'as the way to measure performance', is that it potentially falls apart if you compare the 2 engines, with the same displacement and number and configuration of cylinders. I have no doubt that you'll ignore this because it potentially weighs against OHV engines in comparison to DOHC.

You were the one saying that the BMWs 10 cylinder engine is so supreme to Corvettes LS2 which in fact is not the case. I said if you want to compare the performance of ENGINES then you can't ignore the weight. If you want to compare performance of cars as a whole, again weight is an issue. Again, exactly same car, exactly same everything, but one has a LS2 and the other BMW 10 cyl., which one do you think will have better acceleration? Which one is more mod friendly?

Two less cylinders indeed, just an extra 2 litres required to make up the difference in power. That really does sound like the stereotypical 'Because bigger is better, an American Tradition' lazy arsed approach to building an engine.

But your statement above, really does highlight the main problem with OHV engines, that to produce comparable power, a significant increase in displacement is required, which is a detrimental characteristic in some countries.

So, I'd like to ask you a question in relation to your statement.

Would you still take a 7.0 V8 OHV making 505BHP over a 7.0 V8 DOHC making 707BHP? Equal displacement. Equal number of cylinders.

Now you are changing the subject, we were comparing two specific engines, if you are asking me which engine is better, the BMW V10 or LS2 I say definately LS2, by weighting less I can also add mods to it to have even greater power if you are talking about performance only. None of the big engines are really efficient and I don't think efficiency is the number one priority in designing engines such as these.

 

[aloofman]

Actually both are co-related to each other. Let say you have the same exact car with same exact frame, same options, same weight (minus the engine). One of them has a Corvettes V8 engine and the other has a BMW V10 engine, guess which one will have a better 0-60 time?

Where can I shop for this car with these two engine options? It's a hypothetical question. Unless you're going through the trouble of putting a different engine in a car, the whole car including the engine matters more than the weight of just the engine.

Less stress on the engine means better engine reliability.

Obviously. But in the real world, I don't see how a large-displacement, OHV engine has to be more reliable than a smaller-displacement, OHC engine. There are so many factors involved there. How effective is it's cooling system? How tight are the tolerances and seals? Is the vehicle used for hauling cargo in the city? Or highway cruising? What about the transmission gearing? There are so many things that affect engine wear, that I don't see how a blanket statement about OHV vs. OHC reliability can be more than academic either way.

These two engine designs each have their pros and cons. Automakers use them for different reasons. If OHV were such a terrible design, no one would use it anymore. If OHC were a scam, then everyone would still be using OHV. The car-loving public reaps the benefits of both.

 

[blitzkrieg79]

Where can I shop for this car with these two engine options? It's a hypothetical question. Unless you're going through the trouble of putting a different engine in a car, the whole car including the engine matters more than the weight of just the engine.




Obviously. But in the real world, I don't see how a large-displacement, OHV engine has to be more reliable than a smaller-displacement, OHC engine. There are so many factors involved there. How effective is it's cooling system? How tight are the tolerances and seals? Is the vehicle used for hauling cargo in the city? Or highway cruising? What about the transmission gearing? There are so many things that affect engine wear, that I don't see how a blanket statement about OHV vs. OHC reliability can be more than academic either way.

These two engine designs each have their pros and cons. Automakers use them for different reasons. If OHV were such a terrible design, no one would use it anymore. If OHC were a scam, then everyone would still be using OHV. The car-loving public reaps the benefits of both.

If I had to really get into discussion about engines then I guess I would have to write freaking essays and get into detailed specifics about how it all matters. Of course that the total car performance is not only measured by the engine put inside the car. Cooling is very important to engines performance. Even the same engine but with a different exhaust setup will turn different performance. We were just comparing the LS2 to V10 of BMW, I guess by accident I might have expanded the subject.

And for the last time, I am not saying that OHV is better than OHC and vice-versa, all I am saying that the LS2 is a better performance oriented engine than BMW V10. It's a specific case.

 

[Lord Blackadder]

Now you are changing the subject, we were comparing two specific engines, if you are asking me which engine is better, the BMW V10 or LS2 I say definately LS2, by weighting less I can also add mods to it to have even greater power if you are talking about performance only. None of the big engines are really efficient and I don't think efficiency is the number one priority in designing engines such as these.

Actually, the "efficiency" of any engine is the ultimate goal - efficiency gets the maximum amount of power out of the fuel and has the smallest amount of parasitic loss due to friction, high rotating mass or inefficient combustion.

The mod-ability of an engine has something to do with design but even more to do with the existence of a large aftermarket or OEM support of upgrade kits and parts, so that isn't really a fair argument.

 

[blitzkrieg79]

Actually, the "efficiency" of any engine is the ultimate goal - efficiency gets the maximum amount of power out of the fuel and has the smallest amount of parasitic loss due to friction, high rotating mass or inefficient combustion.

The mod-ability of an engine has something to do with design but even more to do with the existence of a large aftermarket or OEM support of upgrade kits and parts, so that isn't really a fair argument.

If efficiency would be #1 priority then we wouldn't see those large displacement supercar engines being developed in mass quantities. The number one priority for those kinds of engines is definately getting the most horsepower/torque out of it. I am not saying that fuel efficiency is not important but in this case it's not a #1 priority. Efficiency is important in cheaper, daily driver cars, people who buy a Corvette or a BMW V10 could care less about MPG, it's all about image and performance, and I am more than sure that a person that is able to afford cars like these can also afford to put a full gas of tank in them on daily basis.

Mod-ability has to do a lot with the design of the engine block, look at the 4G63 found in the Lancer Evo, small 2.0l engine (286HP stock, of course Turbo, but then again not every engine can handle Turbos to begin with and has to be designed with Turbos in mind) that is capable of making 600HP without touching it's block (and even more with slight block mods). Try that with the Corolla or Civic engine (comparable displacement class although both are 1.8l but still they can't get anywhere near those numbers).

 

[quagmire]

Okay... let me put this to you. If the fabled pushrod is the better engine. Then why is it now considered such a niche design? and why are all the other car manufacturers around the world not aware of this oversight?

Because the media has pushed it as that. Praising DOHC like it was the second coming and bashing OHV like it was satan. Now some of the bashing is due to GM and Ford's arrogance back in the 80's and slacked off on the refinement part of designing the engine. If someone who doesn't know much about cars and reads Motortrend and they say the 3500 VVT in the Aura XE is crude and unrefined due to it being OHV, you think the person will go to the dealer and test drive the XE to see how bad it really is? No, they will listen to Motortrend and not look at the XE because MT said it is unrefined. Although it might not be the case( I haven't driven the XE. I own the XR with the 3.6 DOHC V6). The media has pushed DOHC as a modern engine even though it is older then OHV design. Plus, GM is proving OHV can have the same features as DOHC with VVT on the 3500 and 3900 V6( although VVT is easier to implement on DOHC). GM is working on a 3 valve design OHV engine.

Anyway, as blitz said both designs have there advantages and disadvantages. I am not saying DOHC is crap and OHV is the best. Yes, in Europe having a smaller displacement engine is better due to taxes put on high displacement engines( then again, if you're going to buy a Z06 or a Ferrari, I think you can afford that tax).

PS: The LS2 is 6 liters. The LS7 is 7 liters.

 

[iGav]

You were the one saying that the BMWs 10 cylinder engine is so supreme to Corvettes LS2 which in fact is not the case.

Now show me where I said that? I did say however that I'd take either the Audi V8 or BMW V10 over the 6 Litre LS2 V8. And I would. Every single time.

I said if you want to compare the performance of ENGINES then you can't ignore the weight.

Not originally. You said.

if you really wanna measure performance of an engine forget the displacement and the number of cylinders and just go with amount of horsepower/torque produced per actual weight of the engine.

Which is implies that the horsepower/torque for a given weight is the better way of measuring an engines performance, and I merely pointed out that this is a flawed statement. And it is.

If you want to compare performance of cars as a whole, again weight is an issue. Again, exactly same car, exactly same everything, but one has a LS2 and the other BMW 10 cyl., which one do you think will have better acceleration? Which one is more mod friendly?

I've never stated that weight isn't an issue. I pointed out that your statement regarding power/weight as the real way of measuring engine performance as being nonsense, and it is.

Please read what I write 'eh.

You were the one saying that the BMWs 10 cylinder engine is so supreme to Corvettes LS2 which in fact is not the case.

Read what I said again. And yes, I do consider BMW's 5 litre V10 (and Audi's 4.2 V8) superior over the 6 litre V8 LS2 engine. Which is, if you care to read back, what I was comparing them both to.

Quagmire bought up the 7 litre V8, because that's the only way he could come up with a comparable engine, which was to do it the good old american way, and increase the displacement.

Of course increasing the displacement of one engine, so that it's a whole 2 litres more than it's competition isn't exactly fair, unless you're willing to bump the other up by the equivalent amount so that the displacement is comparable. But then, you find yourself back in the same position again. E.g. Behind.

Now you are changing the subject, we were comparing two specific engines

I've changed nothing, and no we weren't. Read what I've said in this thread.

It is you and quagmire that have changed the subject engines, from the 6 litre V8 LS2 engine (which I lightheartedly took the mickey out of) to an engine that was then bumped up by quagmire by a whole 1 litre (to 7 litres) to make it comparable to BMW's 5 litre V10 engine, and this is the engine that you now appear to be referencing... I was merely playing ball on the subject.

I have consistently referred to both Audi's 4.2 litre V8 and BMW's 5 litre V10 throughout this thread. Because of quagmire's insistence at increasing one engine's displacement to try and make it competitive, and the discrepancy in cylinder configuration between a V8 and V10, it was easier, and unarguably more fair to compare like for like, with regards to both displacement and the number of cylinders.

Do you not agree?

if you are asking me which engine is better, the BMW V10 or LS2 I say definately LS2.

Would you rather take the BMW 5 litre V10 or the 6 litre V8 LS2 engine? which was the original point of discussion. Forget modding, forget everything else, other than these two engines. Which one would you take, and why?

Regarding the 7 Litre LS7 that you and quagmire are both now referring. As long as I can increase the displacement of BMW's V10 by the same amount, would you rather have a 6 litre V10 (now at over 600BHP, and wailing like a BanSidhe having an orgasm) or the 7 litre V8?

But of course, one engine has 2 cylinders more, so why not make the comparison more even, with identical displacement and the number of cylinders.

Would you still take a 7.0 V8 OHV making 505BHP over a 7.0 V8 DOHC making 707BHP? Equal displacement. Equal number of cylinders.

 

[quagmire]

I don't really care about displacement. And to answer your question, I would take the 7 liter DOHC V8 with 707 HP simply because it has more HP not because of it being DOHC or having a good HP/L ratio.

 

[blitzkrieg79]

Now show me where I said that? I did say however that I'd take either the Audi V8 or BMW V10 over the 6 Litre LS2 V8. And I would. Every single time.

I don't know about you but when I say that I would take LS2 over the BMW V10 it means that I think it is a better (supreme) engine to the other.

Which is implies that the horsepower/torque for a given weight is the better way of measuring an engines performance, and I merely pointed out that this is a flawed statement. And it is.

I've never stated that weight isn't an issue. I pointed out that your statement regarding power/weight as the real way of measuring engine performance as being nonsense, and it is.

LOL, in your eyes it is but thankfully you don't design performance cars I do

Please read what I write 'eh.

Looks like I am not the only one without reading comprehension skills, whats worse, you write one sentence and follow it by contradicting it.

Read what I said again. And yes, I do consider BMW's 5 litre V10 (and Audi's 4.2 V8) superior over the 6 litre V8 LS2 engine. Which is, if you care to read back, what I was comparing them both to.

Quagmire bought up the 7 litre V8, because that's the only way he could come up with a comparable engine, which was to do it the good old american way, and increase the displacement.

Read again, I was only comparing two engines, the BMW V10 and the 6.0l LS2 that can be found in a Vette.

Of course increasing the displacement of one engine, so that it's a whole 2 litres more than it's competition isn't exactly fair, unless you're willing to bump the other up by the equivalent amount so that the displacement is comparable. But then, you find yourself back in the same position again. E.g. Behind.

Of course compressing small engines beyond 11.0:1 ratios while increasing the HP numbers will bring a lot of reliability to European cars which when you look at the statistics offer supreme reliability over Japanese and American counterparts. We all know that British, Italians, Germans (VW), and French produce the most reliable cars in the world.

Would you rather take the BMW 5 litre V10 or the 6 litre V8 LS2 engine? which was the original point of discussion. Forget modding, forget everything else, other than these two engines. Which one would you take, and why?

I work for a company that designs high performance after-market mod parts for various automakers. If I would ever buy a car such as Corvette or BMW, the modding potential woud play a crucial role in buying the actual car. I know for a fact that the LS2 can handle over 1000HP (I have seen one that was over 1300HP), however the most I ever seen a BMW with was maybe around 800HP. Big difference. Maybe you can ignore mods but I can't. Those are high performance sports cars meant for speed.

Would you still take a 7.0 V8 OHV making 505BHP over a 7.0 V8 DOHC making 707BHP? Equal displacement. Equal number of cylinders.

That depends on the price, DOHC engines are more complex and more expensive, if the price difference between 7.0 V8 OHV and 7.0 V8 DOHC would be greater than a $3500 mod I can put inside the 7.0 V8 OHV to get it over 700 BHP I would pick the 7.0 V8 OHV

 

[Lord Blackadder]

If efficiency would be #1 priority then we wouldn't see those large displacement supercar engines being developed in mass quantities. The number one priority for those kinds of engines is definately getting the most horsepower/torque out of it. I am not saying that fuel efficiency is not important but in this case it's not a #1 priority. Efficiency is important in cheaper, daily driver cars, people who buy a Corvette or a BMW V10 could care less about MPG, it's all about image and performance, and I am more than sure that a person that is able to afford cars like these can also afford to put a full gas of tank in them on daily basis.

I'm speaking of "efficiency" more in terms of physics. A more efficient design produces more power, all else being equal. Pushrod engines usually have a higher rotating mass, which means more of the power produced by the engine goes back into rotating the camshaft than it would in an OHC engine. More mass also means less revs. This means less horsepower per unit of displacement than a more efficient engine with less parasitic loss.

There's no doubt about it, GM builds some of the most high-tech pushrod engines around, and have worked hard at overcoming the pushrod's limitations....but at the same time there's no doubt in my mind that, all else bing equal, an OHC engine will rev higher and produce more net power than a pushrod engine. It's a proven fact.

Mod-ability has to do a lot with the design of the engine block, look at the 4G63 found in the Lancer Evo, small 2.0l engine (286HP stock, of course Turbo, but then again not every engine can handle Turbos to begin with and has to be designed with Turbos in mind) that is capable of making 600HP without touching it's block (and even more with slight block mods). Try that with the Corolla or Civic engine (comparable displacement class although both are 1.8l but still they can't get anywhere near those numbers).

My Nissan Altima's KA24DE 2.4L has been known to handle 400+hp turbo setups with stock internals, mostly because of the use of forged rather than cast components. You'll find that to be a big factor. Also, cast-iron blocks are easy to bore out as opposed to all-aluminum engines with steel cylinder sleeves like most Honda engines. Still, a dedicated aftermarket can work around most issues, which is why we see tiny Honda engines producing ridiculous power numbers

To be honest though, modification is a sideshow to our main issue here - sure, there are a lot of pushrod racing engines out there with excellent specific outputs - but OHC racing engines of the same displacement will always be more powerful. Why do you think the old GT40 LeMans winners got ~485hp with 7 liters of pushrod versus ~450hp from 4 liters of Ferrari DOHC? The Fords won, of course, but not becuase of Ferrari's design choices versus Ford's.

That depends on the price, DOHC engines are more complex and more expensive, if the price difference between 7.0 V8 OHV and 7.0 V8 DOHC would be greater than a $3500 mod I can put inside the 7.0 V8 OHV to get it over 700 BHP I would pick the 7.0 V8 OHV

But by modifying the OHV you make it more complex and expensive...it's a vicious cycle. The OHC layout always gives an engine an advantage in rev ceiling and power output over an otherwise identical pushrod engine.

 

[blitzkrieg79]

I'm speaking of "efficiency" more in terms of physics. A more efficient design produces more power, all else being equal. Pushrod engines usually have a higher rotating mass, which means more of the power produced by the engine goes back into rotating the camshaft than it would in an OHC engine. More mass also means less revs. This means less horsepower per unit of displacement than a more efficient engine with less parasitic loss.

There's no doubt about it, GM builds some of the most high-tech pushrod engines around, and have worked hard at overcoming the pushrod's limitations....but at the same time there's no doubt in my mind that, all else bing equal, an OHC engine will rev higher and produce more net power than a pushrod engine. It's a proven fact.



My Nissan Altima's KA24DE 2.4L has been known to handle 400+hp turbo setups with stock internals, mostly because of the use of forged rather than cast components. You'll find that to be a big factor. Also, cast-iron blocks are easy to bore out as opposed to all-aluminum engines with steel cylinder sleeves like most Honda engines. Still, a dedicated aftermarket can work around most issues, which is why we see tiny Honda engines producing ridiculous power numbers

To be honest though, modification is a sideshow to our main issue here - sure, there are a lot of pushrod racing engines out there with excellent specific outputs - but OHC racing engines of the same displacement will always be more powerful. Why do you think the old GT40 LeMans winners got ~485hp with 7 liters of pushrod versus ~450hp from 4 liters of Ferrari DOHC? The Fords won, of course, but not becuase of Ferrari's design choices versus Ford's.



But by modifying the OHV you make it more complex and expensive...it's a vicious cycle. The OHC layout always gives an engine an advantage in rev ceiling and power output over an otherwise identical pushrod engine.

I agree with everything you are saying, if I were to build an engine from scratch it would definately be DOHC based, I am not arguing that SOHC is superior to DOHC. I was just comparing a specific scenario, engine comparison between LS2 vs BMW V10.

 

[Lord Blackadder]

I agree with everything you are saying, if I were to build an engine from scratch it would definately be DOHC based, I am not arguing that SOHC is superior to DOHC. I was just comparing a specific scenario, engine comparison between LS2 vs BMW V10.

With the LS2 v.s. BMW V10...the V10 does more with its displacement than the LS2. GM engineers knew the pushrod design's limitations and focused on lightening the engine to compensate for the fact that they needed bigger displacement to get the power they wanted. The result is an engine that is quite light for its displacement and very torquey.

The BMW, on the other hand, uses a smaller engine that spins several thousand rpm higher to produce 100 more horsepower and nearly as much torque as the LS2 with 1 liter less displacement.