We seem to be stuck in a bully mentallity,"well our v 8s can do just as good as their 12s,so why should we?"imagine what American ingenuity could do with 4 more cylinders? with ethanol coming in the compression will go up,so why not,scared,or just plain stubborness.  

Ummmm...extra cost for pretty much no benefit in power or economy.  Sounds like a damn good reason to NOT build a V12 to me.

Actually at the moment auto manufacturers are downsizing their V8 programs...going with V6s instead to meet the new CAFE requirements.  

Fewer parts, lower costs as well. We've made bigger, we're now going for efficency.  

cause we have proven that all ya need is 8 to get the job done right  

plus do you really want to set the valve lash on a v-12? that's anywhere from 24 to 60 rockers?(one of the ferrari's has 5 vavles per cyclinder) Imaginge trying to port those heads? not only are there 60 of em but there only the size of dimes. I dont even think they are entirely round on those heads, not sure, but still thats a lot of work.  

I think we need just one american 12 just to put ferarri to shame.  

Z06 already runs with and beats (in many cases) the Ferrari F430 (their V8 car) and we have the ZR1 in development to take on and beat the 599GTB (their V12 car) using a supercharged 6.2L V8.  So...why do we need a V12 again?  

If we can already beat them with a v8 imagine how much we could beat them with a v12  

^^ Not much considering how much more the engine will cost...then adding in the additional development cost.  Not to mention the added internal losses from 4 more pistons, at least 8 more valves, 8 more rockers (OHV), 8 more lifters(OHV), and 8 more pushrods (OHV)...

Of course...we could go OHC...but then we're adding weight and making the engine physically larger...

There is no reason to add 4 more pistons to already great engines.  

oh just go hop up an old caddy v-16 roll into germany capone style and smoke them.  

Let's see, why don't American automakers build a V-12? Well other than developement costs and virtually no performance gains, have you seen that gas is $3.90 a gallon for premium? The Dodge Viper is a V-10 and it avgs. 10 MPG on the freeway with a freaking 6-speed!! Imagine what kinda mileage you'd get with a V-12 with NA tuning. You'd see 12 MPG coasting down a 70% grade in PA, with a 20mph tailwind, in Neutral, at 75 MPH.
V-8's get the job done just as well and do it more economically, and efficiently.  

There's no point to it. V-12s are physically big, complicated, and not well suited for mass production. The quote above is right, there's nothing a V-12 from Europe does that our American V-8s don't.

Back when GM was developing a new big motor for their trucks, the engineers toyed around with making a V-10 LS based engine. They built two prototypes, and testing revealed they weren't great. Out of that research came the drive and design for the 8.1L big block.  

there goes the bully mentality,most answered why,if a v8 can do it... well obviously not a vette costs what 60 grand for what,plastic fenders,plastic quarters,and a v8 that can easily be surpassed by a teenager with a book and a medium fat wallet, the viper,its under powered for what its capable of,theres people with 180 mph hondas living in houston. all the fastest cars in the world run a V12.the koenigsegg v12 a AMG mercedies?V12,the stallions from italy,again V12.Americans seem to think we have the very best products in the world and if you dont like i
t ill browbeat you saying how my 70 ss 454 was the fastest car in the world,over 36 years ago.All ime getting at is why wont an american company go out and challenge the best in the world on their own turf. Ford did it,why not again? there are people with the money to spend and burn to go out and do it.I love my V8 but i think wouldnt it be cool to have a 8 litre or so hemi headed dohc 4 valve per cylinder twin plug,twin turbo charged intercooled  all wheel drive ALL AMERICAN SUPERCAR?
it would eat vetts for breakfast and poo silverados for lunch.
but ime pretty sure ime in the wrong forum for those kind of thoughts,no ,no forward thinkin here...or is there..  

Uh...dude...the Ford GT, the Corvette Z06, and the Viper (with its V10) all out run Ferrari's late 575 Maranello with its V12...

The Porsche Carrera GT is running a V10.

The Saleen S7 is one of the fastest cars in the world...and its running a V8...hell its got, in TT competition package form, a higher top speed than any production Ferrari (including the F40, F50, and Enzo)...

You're going solely off perception...and not reality.  Reality is the LS V8's used by GM are compact, light weight, and capable of putting out PLENTY of power (as shown in this month's Car Craft)...the current Viper with its V10 is putting down 600 HP...the upcoming Corvette ZR1 with its V8 is putting out 638 HP (both of which are on par with the Ferrari 599GTB with its V12)...the "problem" with American cars is generally handling...not power.  A V12 isn't going to help handling.

And the upcoming ZR1, according to GM, will beat any production car on any track...how's that for taking on the world's best?  We'll have to see whether or not they get it done...but they are doing EXACTLY what you say...without wasting money developing a useless V12.

Oh...and an AMG Mercedees is NOT a fast car...the SLR McLaren is the fastest Mercedes to have run around Nurburgring...it ran a 7 minute, 40 second lap...the Ford GT with its V8 ran a 7:42...the Z06 Corvette with its V8 ran a 7:43...the Nissan GT-R with its V6 ran a 7:29...

And for the record...that V6 powered Nissan out-ran the Koenigsegg CCR on the Nurburgring by 5 seconds...granted the Koenigsegg ran in cold conditions...but the Nissan was 600 kg heavier (about 1300 lbs) and had 240 HP less...

V12 means nothing...how much power you can get to the ground means EVERYTHING.  Nissan's incredible AWD system is a hell of a lot more impressive than adding a few cylinders just to say you have them...

How's that for forward thinking?  

Maybe this is just a case of 'piston envy'. Mine has more than yours.  The Europeans have always been enamored of small displacement high revving motors.  The Dodge V-10 is 488 cubes, Ferraris often don't go above half to two thirds that number.  Yes, it would be interesting to see what American ingenuity could produce but since all three American companies are in financial difficulty and have the new CAFE regs and mega costly gas prices to contend with it would be ingenuity improperly placed.  How about a small displacement turbo charged hybrid (shudder) AWD with CVT that folds up into a briefcase and won't get shreded the first time it comes in contact with a 18 wheeler driven by a guy torqued about $10 a gallon Ultra low sulpher diesel.  Now that would be inqenuity in action.  I'll just keep my 440 powered '68 B-body under wraps for the day i have to make that cross country run to avoid the Prius driving Eco-Nazis that will be roaming the hinterlands once the lefties take over the country.  (hmm, i think i covered all the bases.)