DOHC or SIBC for Corvette C7

[regfootball]

i'd like to see them do both, a v8 pushrod, although smaller, and a v6 twin turbo. and maybe a kahuna v8 dohc turbo.

thing is which engine will score better when tested on the epa cycle? when they run a 3200 pound car at gramma speeds on the epa test loop?

we know the corvette gets good highway mpg in the real world, but i am guessing an ohc v6 like the camaro has with an 8 speed dual clutch may just do that much better.

and if 2/3 of the vettes sold are basic vettes, and this is what gets put in them, a nice 360+ hp v6 that can score 32+ on the highway......can you see where in Obamanation / greenhell / they made us tighten CAFEland I am going with this? Its the same reason why GM would rather sell you a nice 4 cyl Malibu for your 25 thousand bucks instead of a nice basic RWD v6 g8 for your 25 thousand bucks.......

if i take a 3700 pound camaro at 29 mpg and interpolate the weight down to 3200 pounds.......that is a weight reduction of 13.5%. if i increase the 29 mpg highway figure by the same 13.5% I get .......... 33 mpg.......... my guess is that goes to 35 with an 8 speed dual clutch.

what highway mpg does the corvette get now?

Edited November 18, 2009 by regfootball

[CaddyXLR-V]

You've been told time and time again. DOHC is actually older than pushrod.

You've also been told time and time again that the reason pushrods are gone from 4-cylinders (or any inline arrangement) is because there are zero packaging advantages.

The V6 pushrods are dying because they've gotten zero investment dollars because even the best DOHC beating pushrod would never satisfy the import humpers like you. You'd find some assinine reason to hate it like "doesn't rev to 8,000 rpm".

You've already been shown that blindly choosing a DOHC engine over a pushrod engine will have you looking at Chevy or Cadillac taillights growing smaller in the distance.

99% of non-gearheads don't have a CLUE what the acronym DOHC even stands for let alone means. They only like it "better" because Consumer Reports told them to.

The Buick Lucerne I rented had the 3.9 liter pushrod. I drove for 20 miles in 3rd gear at 75mph and the only reason I eventually noticed is because the instant MPG reading seemed a bit low. There is no audible or even visceral difference in the Lucerne at 75mph in 4 or 75mph in 3.

66Stang can back me up on this one, I took him out for a ride in it.

You have to love hundreds of pounds of sound deadening materials. That tells nothing about the engine.

[Drew Dowdell]

It wasn't just sound. You couldn't even feel it.

[CaddyXLR-V]

I don't understand how it can be argued that more valve mass, less valves and worse breathing, is better for a performance car. The only arguement that makes sense is nostalgia. The Corvette performs because of light weight, and a big engine, not because it is OHC.

[Camino LS6]

There simply is zero advantage to the idea of developing a new DOHC V8, and it won't happen.

Back when GM commanded a much bigger slice of the market, it made sense to do the Northstar for Caddy (if only for the snob-appeal). Right now, there is no earthly reason to do it - not even for Caddy.

GM uses the pushrod V8 because it is the best engine for the job, and no one does it better than GM.

DOHC as a measure of technology and sophistication is a pure red herring.

[CaddyXLR-V]

There simply is zero advantage to the idea of developing a new DOHC V8, and it won't happen.

Back when GM commanded a much bigger slice of the market, it made sense to do the Northstar for Caddy (if only for the snob-appeal). Right now, there is no earthly reason to do it - not even for Caddy.

GM uses the pushrod V8 because it is the best engine for the job, and no one does it better than GM.

DOHC as a measure of technology and sophistication is a pure red herring.

That's the only engine GM has for the job. The Northstar was developed when, 1992?

And DOHC is not a measure of technology, it just allows the engine to take in more air, with better control of the valves. For everyone who says 8 cyl is better than 4 or 6, why wouldn't 4 valves be better than 2? Why would less valve float be a bad thing?

I just think if GM stopped making OHV engines in the 60s, and switched to OHC engines, and if Honda and Toyota were still making OHV engines, every one here would be arguing how much better OHC is, because GM does it.

[Camino LS6]

The point is that DOHC is not superior to pushrods, it is merely an alternative.

Both approaches have advantages and disadvantages in theory, but GM has demonstrated again and again that a pushrod engine can be superior to the competition when done right.

And GM does it right.

[CaddyXLR-V]

The point is that DOHC is not superior to pushrods, it is merely an alternative.

Both approaches have advantages and disadvantages in theory, but GM has demonstrated again and again that a pushrod engine can be superior to the competition when done right.

And GM does it right.

GM does a good job with the V8s. But that doesn't mean they couldn't do better. Their V6s suck. 3.5L in the Malibu doesn't sound healthy. And my 99 2.5L Mazda 626 felt more powerful than the 04 3.5L Malibu that I am driving now, and was much smoother and sounded better.

GM could make a V8 sharing parts with the 3.6L, and make a 4.8 V8 with about 406hp. That would be a better engine for a Cadillac, and wouldn't be a bad base engine for the Corvette either.

[Camino LS6]

There is a whole host of reasons why this isn't a good idea, a business case cannot be made.

[CaddyXLR-V]

There is a whole host of reasons why this isn't a good idea, a business case cannot be made.

I don't understand why every other automaker can make a business case for it, but GM can't. GM always takes the cheaper option. According to GM, they couldn't make a business case for Pontiac, or to sell the UTE here, or to put more manuals in cars. It all comes down to cost. Whatever is cheaper, that is what they choose.

[Camino LS6]

It is much bigger than just development costs.

Warranty exposure alone precludes the idea.

GM's V8s are one of its strengths, a move to DOHC would jeopardize an overwhelming majority of GM's sales by impacting the trucks/suvs, Corvette, Camaro, CTS-V...

Any flaw could sink the whole ship.

Such a silly gamble all for the questionable goal of pleasing auto rags and DOHC fanboys just isn't going to happen.

Imagine then what impact this would have on CAFE and you'll see another fatal flaw with this idea.

Then think about how GM's V8 products are used. How long do you think these DOHC powerplants would survive under the abusive conditions many buyers subject them to? You'd be risking the most loyal customers GM has when the reliability tanked.

Such an engine would only make sense applied the way Northstar was, and even then would be highly unlikely to return a profit.

No, GM's V8s will evolve as they always have, the advances will come at a steady pace.

A DOHC "revolution" just isn't in the cards, nor would it be advantageous if it did.

[Drew Dowdell]

I don't understand how it can be argued that more valve mass, less valves and worse breathing, is better for a performance car. The only arguement that makes sense is nostalgia. The Corvette performs because of light weight, and a big engine, not because it is OHC.

I don't understand how an engine that weighs more yet has less displacement, has more internal friction, poor packaging options, and a higher center of gravity would be better for performance.... but that's just me....... and GM apparently.

I don't understand how it can be argued that more valve mass, less valves and worse breathing, is better for a performance car. The only arguement that makes sense is nostalgia. The Corvette performs because of light weight, and a big engine, not because it is OHC.

I don't understand how an engine that weighs more yet has less displacement, has more internal friction, poor packaging options, and a higher center of gravity would be better for performance.... but that's just me....... and GM apparently.

[CaddyXLR-V]

I don't understand how an engine that weighs more yet has less displacement, has more internal friction, poor packaging options, and a higher center of gravity would be better for performance.... but that's just me....... and GM apparently.

I don't understand how an engine that weighs more yet has less displacement, has more internal friction, poor packaging options, and a higher center of gravity would be better for performance.... but that's just me....... and GM apparently.

So your favorite engine would be a pushrod flat 4? Less internal friction lower weight, and a lower center of gravity. Why use a V8 when it is heavier and has higher internal friction than a 4cyl or V6?

[Drew Dowdell]

That's the only engine GM has for the job. The Northstar was developed when, 1992?

And DOHC is not a measure of technology, it just allows the engine to take in more air, with better control of the valves. For everyone who says 8 cyl is better than 4 or 6, why wouldn't 4 valves be better than 2? Why would less valve float be a bad thing?

I just think if GM stopped making OHV engines in the 60s, and switched to OHC engines, and if Honda and Toyota were still making OHV engines, every one here would be arguing how much better OHC is, because GM does it.

Who said pushrods could only have 2 valves?

If you're going to go on about valves and good breathing, why not a 5-valve setup like VW has been using since 2000? Why are Toyota, Honda (which is mostly SOHC btw), BMW, and Nissan so far behind on this?

[Drew Dowdell]

So your favorite engine would be a pushrod flat 4? Less internal friction lower weight, and a lower center of gravity. Why use a V8 when it is heavier and has higher internal friction than a 4cyl or V6?

V8 to V8 there SMK, a DOHC V8 has more moving parts and more internal friction than a pushrod

[CaddyXLR-V]

V8 to V8 there SMK, a DOHC V8 has more moving parts and more internal friction than a pushrod

And V8 also has more moving parts and internal friction than a V6, but I don't see you advocating that switch.

It's really simple. Engines need to breathe to make power. More valves is better than less valves. More control over the valves is better than less control especially in a performance car.

Edited November 18, 2009 by CaddyXLR-V

[Drew Dowdell]

I don't understand why every other automaker can make a business case for it, but GM can't. GM always takes the cheaper option. According to GM, they couldn't make a business case for Pontiac, or to sell the UTE here, or to put more manuals in cars. It all comes down to cost. Whatever is cheaper, that is what they choose.

So show us the business case for DOHC in the 'Vette. What does it buy you that the current Vette cannot do now?

And V8 also has more moving parts and internal friction than a V6, but I don't see you advocating that switch.

It's really simple. Engines need to breathe to make power. More valves is better than less valves. More control over the valves is better than less control especially in a performace car.

Why do you have the assumption that VVT and more valves cannot be added to the engine now?

[CaddyXLR-V]

So show us the business case for DOHC in the 'Vette. What does it buy you that the current Vette cannot do now?

Why do you have the assumption that VVT and more valves cannot be added to the engine now?

Higher redline, higher top speed, more power if designed right. More percieved refinement. VVT can also be added to DOHC easier.

More valves can be added, with twice as many pushrods, and they still need to come up with a design for where to put those pushrods, and still less control over the valves. Who knows how reliable that will be.

[cletus8269]

The fact remains that one of the fastest, most exclusive naturally-aspirated Corvettes in the history of the name was DOHC.

DOHC LT5 aluminum 5.7 L (349 cu in) small-block V8

405 hp @ 5,800 rpm

385 ft lbs @ 4800 rpm

Compression Ratio 11:1

Bore x Stroke 99 x 93 mm

LS6 aluminum 346 (5.7L) small block v8

405hp @ 6,000 rpm

400 ft lbs @ 4800 rpm

Compression Ratio: 10.5:1

Bore x Stroke: 99.00 x 92.00mm

http://www.cheersandgears.com/index.php/topic/40869-which-engine-for-the-c7-corvette/page__view__findpost__p__534612

[CaddyXLR-V]

DOHC LT5 aluminum 5.7 L (349 cu in) small-block V8 1992

405 hp @ 5,800 rpm

385 ft lbs @ 4800 rpm

Compression Ratio 11:1

Bore x Stroke 99 x 93 mm

LS6 aluminum 346 (5.7L) small block v8 2002

405hp @ 6,000 rpm

400 ft lbs @ 4800 rpm

Compression Ratio: 10.5:1

Bore x Stroke: 99.00 x 92.00mm

http://www.cheersandgears.com/index.php/topic/40869-which-engine-for-the-c7-corvette/page__view__findpost__p__534612

Doesn't seem like much of an advance in ten years time. GM could probably get 600hp out of a 5.7L DOHC if they tried now.

Edited November 18, 2009 by CaddyXLR-V

[Drew Dowdell]

Higher redline, higher top speed, more power if designed right. More percieved refinement. VVT can also be added to DOHC easier.

More valves can be added, with twice as many pushrods, and they still need to come up with a design for where to put those pushrods, and still less control over the valves. Who knows how reliable that will be.

They already have VVT for the pushrods.

Who cares about higher redline? that's what gears are for.

Did you just imply that the competitors to the Corvette aren't designed right?

Much like a SOHC can still have 4 valves per cylinder, a single pushrod can actuate more than one valve.

Perceived refinement is hogwash.... particularly in this segment.

[Justin Bimmer]

I don't think I have ever seen an automotive journalist say the Corvette's engine is unrefined.

While we all get hung up on performance. Don't forget about fuel economy.

[Drew Dowdell]

Doesn't seem like much of an advance in ten years time. GM could probably get 600hp out of a 5.7L DOHC if they tried now.

What are the exterior physical dimensions of each engine. The LT5 just barely fit in the 'Vette engine bay.

What displacement could the pushrod be increased to and still be physically smaller than the DOHC engine?

[CaddyXLR-V]

They already have VVT for the pushrods.

Who cares about higher redline? that's what gears are for.

Did you just imply that the competitors to the Corvette aren't designed right?

Much like a SOHC can still have 4 valves per cylinder, a single pushrod can actuate more than one valve.

Perceived refinement is hogwash.... particularly in this segment.

Higher redline would make more power. It would also need to shift less. Perception is reality, in every segment. Maybe if Buicks engines had more refinement, they could cut down on the sound deadening materials. Don't they also use shock absorbing motor mounts too?

[regfootball]

There simply is zero advantage to the idea of developing a new DOHC V8, and it won't happen.

Back when GM commanded a much bigger slice of the market, it made sense to do the Northstar for Caddy (if only for the snob-appeal). Right now, there is no earthly reason to do it - not even for Caddy.

GM uses the pushrod V8 because it is the best engine for the job, and no one does it better than GM.

DOHC as a measure of technology and sophistication is a pure red herring.

no, caddy needs a v8. for the sixteen / flagship.

[regfootball]

I don't understand why every other automaker can make a business case for it, but GM can't. GM always takes the cheaper option. According to GM, they couldn't make a business case for Pontiac, or to sell the UTE here, or to put more manuals in cars. It all comes down to cost. Whatever is cheaper, that is what they choose.

right.

speaking of the UTE> on GMI they have some nice new pics of a real Pontiac grilled SSV ute in red, in you'd we want to see what that looks like on a showroom floor. its curiously missing the Pontiac logo however.....

[Drew Dowdell]

Higher redline would make more power. It would also need to shift less. Perception is reality, in every segment. Maybe if Buicks engines had more refinement, they could cut down on the sound deadening materials. Don't they also use shock absorbing motor mounts too?

a higher redline does not mean more power. Many/Most engines' power tapers off before redline. Redline and Max power are almost never at the same RPM.

I"m sure Buick does use shock absorbing motor mounts also... but nothing nearly as high tech as the active motor mounts Honda uses in some of it's V6es.

[CaddyXLR-V]

a higher redline does not mean more power. Many/Most engines' power tapers off before redline. Redline and Max power are almost never at the same RPM.

I"m sure Buick does use shock absorbing motor mounts also... but nothing nearly as high tech as the active motor mounts Honda uses in some of it's V6es.

That's why I said if designed right. The engine needs to be designed to take advantage of the higher redline, which will mean more power.

And a quick search shows that the 6.3L AMG engine weighs about 450lbs, while a 6.0L LS2 weighs 537lbs. Add in a supercharger or turbo and their plumbing to match the power of the DOHC, and the engine gets even heavier.

Edited November 18, 2009 by CaddyXLR-V

[CaddyXLR-V]

Correction to the weights of the engines above. The LS2 weighs 448lbs. The AMG engine is 438lbs. The LS9 is somewhere around 550lbs.

The 3.6L weighs 370, so a V8 based off that would be about 493lbs. I would say the trade off of 50 extra pounds would be worth it.

Edited November 18, 2009 by CaddyXLR-V

[Drew Dowdell]

How much does the AMG engine cost?

How much of a horsepower bump would the LS series get if they added direct injection?

How much of a performance bump would the LS series get if they added VVT?

[Justin Bimmer]

AMG Engine HP:518

LS9 Engine HP:638

AMG -120HP

AMG Torque:465

LS9 Torque:604

AMG -139 Torque

AMG +27,000 price

[Chevy Nick]

I don't understand how it can be argued that more valve mass, less valves and worse breathing, is better for a performance car. The only arguement that makes sense is nostalgia. The Corvette performs because of light weight, and a big engine, not because it is OHC.

Caddy XLR-V, from reading your comments, it seems that you don't understand the concept of external displacement, how much physical space an engine occupies. Displacement for displacement, a OHV engine takes up much less space than a DOHC engine. see picture:

As you can see, the 5.0L OHV engine (internal displacement) is significantly smaller than the 4.6L DOHC (internal displacement) engine. If you had to jam a DOHC engine in a corvette engine bay, it might not fit. If it did fit, it would have much less internal displacement, like 3.0L.

OHV engines allow more internal displacement for a given volume of engine bay.

[CaddyXLR-V]

Caddy XLR-V, from reading your comments, it seems that you don't understand the concept of external displacement, how much physical space an engine occupies. Displacement for displacement, a OHV engine takes up much less space than a DOHC engine. see picture:

As you can see, the 5.0L OHV engine (internal displacement) is significantly smaller than the 4.6L DOHC (internal displacement) engine. If you had to jam a DOHC engine in a corvette engine bay, it might not fit. If it did fit, it would have much less internal displacement, like 3.0L.

OHV engines allow more internal displacement for a given volume of engine bay.

No, I completely understand it. Do you not understand that Ford design is not a very good design, and is big even by DOHC standards? And I have done work, and rebuilt both DOHC, and OHV engines before. So I know their size.

Edited November 18, 2009 by CaddyXLR-V

[hyperv6]

Let's not pretend that Ecoboost is anything more than a nice turbo setup. GM is getting 300hp out of it's 2.8 liter "ecoboost" engine in the Cadillac SRX. Some quick math tells me that Cadillac is getting 107hp/liter while Ford is getting 104hp/liter.

What would happen if a turbo were put on the 'Vette? More power of course.

Lets also not forget the 2.0 LNF with the GM Performance Turbo Up grade that is California legal with a 5 year 100,000 mile warranty get 145 HP per liter.

Do not underestimate DI and Turbo. DI thrives on Turbo's. What is the Leno Camaro 3.6 Liter turbo with 425 HP and V6 economy per GM? I think these engines show what GM can do with all the avaiable technology on the small engines. Imagine where they could go on the V8. The added features will be what saves the V8 into the future even if it is more limited.

The point is they have not even scratched the surface yet with the VVt, Turbo DI engines. The end result is the Valves in the LS engine will be the limiting area of the engine. You can only go so big. My company has taken them as large as you can go on the heads we produce.

[hyperv6]

No, I completely understand it. Do you not understand that Ford design is not a very good design, and is big even by DOHC standards? And I have done work, and rebuilt both DOHC, and OHV engines before. So I know their size.

The 4.6 was a paperweight from the start. That is why Ford has the new DOHC engine coming.

The fact remains all but two MFG use multi vlave engine and the two who hold to the old design are Chaper 11. The readson they never moved ahead was the cost to make a new engine just was not their and it was cheaper and more profitable to keep the old engines longer.

The problem is it will take all this new technology and multiple valves to meet the future goverment regs. All the other companies are not doing DOHC and all the other features just because it is cool but because to meet the new CAFE and Emissions they will need the more advanced designs.

At some point GM is going to have to move ahead.

I guess we just have to accept the fact You, I and about every auto MFG san 2 are wrong and the nostalgia gang here are right?

They once told Columbus the earth was flat and in time they came around.

In time the DOHC will surplant the so call SBC. Or they may adapt a similar block with new heads as the bottom end of the LS engine is strong enough to work with more up top. I could see a lite weight engine with multi cams with a similar block.

Edited November 18, 2009 by hyperv6

[Drew Dowdell]

PUSHROD ENGINES ARE NOT LIMITED TO 2 VALVES PER CYLINDER

can we all agree on that at least?

[hyperv6]

PUSHROD ENGINES ARE NOT LIMITED TO 2 VALVES PER CYLINDER

can we all agree on that at least?

No they have been around, GM left them on the Dyno years ago.

[Camino LS6]

And, that would be a more logical and evolutionary approach based on the excellent LS engines.

[smk4565]

I am in agreement with Hyperv6 and CaddyXLR-V. The DOHC is the way to go. GM often does what is cheapest, not what is the best idea (which led to bankruptcy). The pushrod is nostalgia. The Vette was 5.7 liter, then 6.0 liter, then 6.2 liter. To get more power they kept having to make it bigger, if it was so easy to add DI and VVT why hasn't it been done already? And how much can VVT help when there are only 2 valves to vary? 4 variable valves is better than 2 variable valves.

The pushrod vs DOHC argument isn't just V8s, it is all engines. Compare pushrod 4's to DOHC 4's, pushrod V6 to DOHC V6, pushrod V8 to DOHC V8, etc. DOHC is superior, that is why all the 4-cylinders and almost all the V6s are DOHC now. Power output is better, refinement/smoothness are better, and a DOHC 4-cylinder can replace a pushrod V6 and get better mileage, like with the Equinox.

Arguing that a pushrod V8 is better than a DOHC V8 is the same as arguing a pushrod V6 would be better for the CTS or a pushrod 4-cylinder better for the Equinox.

And to the ZR-1 lovers that claim it to be the ultimate in performance, the Koenigsegg has a top speed that is 48 mph higher. The Koenigsegg is only a 4.7 liter engine too, so why can't the ZR-1's 6.2 liter pushrod keep up? It is just fact that DOHC can breath more and create higher end power.

But all that being said, the Vette doesn't compete with Ferrari, Aston or other supercars, it is mid-priced sports car and the interior is by far it's biggest problem.

[smk4565]

And GM needs Revolution, not Evolution. Slow evolution led to bankruptcy as everyone else innovated faster than them, and they did business as usual. Rapid revolution is needed to at least catch up, but hopefully leap frog the competition.

[Camino LS6]

Moving to a DOHC V8 would be suicide, it's that simple.

[A Horse With No Name]

I like the idea of the evolution of the excellent LS series powerplants.

Riding in a Z06 driven "in anger" has convinced me!

Chris

[smk4565]

Moving to a DOHC V8 would be suicide, it's that simple.

So Ferrari, Porsche, Aston Martin, Jaguar, Maserati, BMW, Mercedes, Koenigsegg, and Audi are using the wrong engine? While the Vette has what the Dodge Ram and Chevy Silverado have. If I am building a sports car, I want what Ferrari has, not what the Dodge Ram has.

[Camino LS6]

Fortunately, what you want has no bearing on the issue.

Read my earlier posts (and others) to see why this is such a bad idea. It has nothing to do with Aston or Ferrari.

[Z-06]

So Ferrari, Porsche, Aston Martin, Jaguar, Maserati, BMW, Mercedes, Koenigsegg, and Audi are using the wrong engine? While the Vette has what the Dodge Ram and Chevy Silverado have. If I am building a sports car, I want what Ferrari has, not what the Dodge Ram has.

Where is your favorite brand Bentley?

[smk4565]

Where is your favorite brand Bentley?

I like Bentley, but they use DOHC and pushrod. But they also build tank like cars, not sports cars. And if Bentley had a 6.75 liter DOHC with 2 turbos, I imagine the torque numbers would be even more insane than they already are. A Bentley Arnage redlines at 4500 rpm, that isn't really ideal for a Corvette.

Edited November 19, 2009 by smk4565

[Drew Dowdell]

I am in agreement with Hyperv6 and CaddyXLR-V. The DOHC is the way to go. GM often does what is cheapest, not what is the best idea (which led to bankruptcy). The pushrod is nostalgia. The Vette was 5.7 liter, then 6.0 liter, then 6.2 liter. To get more power they kept having to make it bigger, if it was so easy to add DI and VVT why hasn't it been done already? And how much can VVT help when there are only 2 valves to vary? 4 variable valves is better than 2 variable valves.

The pushrod vs DOHC argument isn't just V8s, it is all engines. Compare pushrod 4's to DOHC 4's, pushrod V6 to DOHC V6, pushrod V8 to DOHC V8, etc. DOHC is superior, that is why all the 4-cylinders and almost all the V6s are DOHC now. Power output is better, refinement/smoothness are better, and a DOHC 4-cylinder can replace a pushrod V6 and get better mileage, like with the Equinox.

Arguing that a pushrod V8 is better than a DOHC V8 is the same as arguing a pushrod V6 would be better for the CTS or a pushrod 4-cylinder better for the Equinox.

And to the ZR-1 lovers that claim it to be the ultimate in performance, the Koenigsegg has a top speed that is 48 mph higher. The Koenigsegg is only a 4.7 liter engine too, so why can't the ZR-1's 6.2 liter pushrod keep up? It is just fact that DOHC can breath more and create higher end power.

But all that being said, the Vette doesn't compete with Ferrari, Aston or other supercars, it is mid-priced sports car and the interior is by far it's biggest problem.

Listen up SMK. I am completely, utterly serious about this.

You will be banned from these threads if you continue.

Understand these following statements before you post again.

1. There is no packaging advantage for pushrod inline engines. That is why DOHC is better on a 4 cylinder.

2. There has been an utter lack of development on pushrod V6 engines. The trait of having pushrods is not the cause of their "inferiority"

3. There is a massive packaging advantage that can be had with a pushrod V8. The differences in external dimensions are gigantic.

4. The Corvette, like the CTS-V, can smack around cars twice it's price and do it with a pushrod.

5. The Koenigsegg is over 5 times the price of a ZR-1. I find no trouble jumping to the conclusion that GM would have no problem coaxing 1,000 HP out of the LS series if they could charge even half that.

[Camino LS6]

And, consider this one last tidbit:

GM can't support two V8 architectures at this time, so they go with the one that works (and works well) across all of the lines that require it.

That simple reality means a pushrod V8.

Period.

[Justin Bimmer]

Why do some people not acknowledge others strong points in these discussions? That is the proper way to have a civil discussion.

[Drew Dowdell]

For those in this thread who wish to learn something, there was already anexcellent discussion between two people who know a thing or two about engines. Do yourselves a favor and read.