dado

Right and if you try really hard you can hear the turbocharger whistle in ANY turbocharged car. So, you point is? There is a reason why the LSA (14/19 MPG -- Camaro ZL1) has notably worse fuel economy numbers compared to the LS3 (16/24 -- Camaro SS). I am citing Camaro numbers for a fairer and more accurate comparison since we are comparing engines not chassis weight and aerodynamics. Point is you don't have to try really hard on CTS-V. In most articles i've read about CTS-v there was observations made about supercharger noise(i assume that is only when you are accelerating with pedal to he floor).Now this is all good and welcome for type of car CTS-V is...but for premium product like something that will go against new s class, audi s8, new maserati quattoporte,porsche panamera or BMW 7. I'm not sure it is acceptable..yes you can hear an engine roaring when you put pedal to the medal..but i'm not sure you can also hear turbochargers spinning. Maybe tested cts-V had problems with superchargers.I've read some CTS-V owners did have some noise problems with their CTS-V and GM change supercharger on their cars. I must admit i'm not big fan of german's product and i don't read test about them as much as i read about Cadillac cars so maybe you can hear turbochargers whine..but i doubt it. And if you want to compare engines..well there are certain criterias that are only specific to an engines..power (power curve) torque (torque curve) weight, size, specific fuel consumption, price, complexity...etc.etc. I am curious to see how would your LT1 "premium" engine compared to engine from mercedes audi, and bmw. As i see it is already falling behind in criteria of power, torque, weight if you take M157 engine for comparison.

Don't forget what top engine does the S class has.It is a twin turbo v12. So this supercharged v8 (if cadilac flagship will go against s class) must not be noisier (no supercharger whine in cabin) than the engine in the S class,Or at least is must not be heard in a cabin .Actually NVH should be on same level. Even on the ZL-1 there is nearly zero supercharger whine... so I'm not sure what tree you think you're barking up here... There is supercharger whine heard in cts-v. And that is a lsa engine. Nobody said it is loud. But you can hear it.

And what do you think high end customer wants? Cars that are worse than s class, A8,7 or better than S class, A8, 7? Few days ago GM announce that it will rise price and prestige of Cadillac cars to be better align with german cars. Why do you think they will do that? Why does GM wants Cadillac to go against Germans cars in luxury class if there are better cars out there? If Cadillac wants to be taken seriously in luxury car market they will have to be better than other cars in that market..And that cars are coming from Mercedes, BMW, Audi. Not Volvo, Lincoln, Acura. Also Cadillac is way behind on image in Europe. And it seems that it lack in image in USA too. Does Mercedes and BMW have over bloated image..Yes. But this is something Cadillac will go against on most markets in the world. So maybe if they build cars that are better than S class or A8 (but i think S class is still being considered king in its class...not to mention there is new one coming soon..but maybe i'm wrong), their image will go up. And maybe after time Cadillac will be considered Standard of the world again. Regarding J.D quality report...there is also J.D. Power 2012 Vehicle Ownership Satisfaction Study and according to this study Mercedes-Benz drivers are the most satisfied. I found this by just typing mercedes benz and J.D. Power. I'm curious is there any category where Cadillac has taken first place in J.D power regarding their cars(best premium cars, most reliable or anything regarding their cars)?

Don't forget what top engine does the S class has.It is a twin turbo v12. So this supercharged v8 (if cadilac flagship will go against s class) must not be noisier (no supercharger whine in cabin) than the engine in the S class,Or at least is must not be heard in a cabin .Actually NVH should be on same level.

Would this premium V8 LT1 be top engine for Cadillac? Even if we are looking at a present V8 engines this "premium" version of LT1 is behind in torque,HP and weight. Just take a look at 5.5 l v8 TT (m157) from Mercedes. This type of a engine is what will future engine in Cadillac compete against. And not just in flagships. GM can make a DOHC v8,v12,v10 etc. but if it isn't better or equal to a engines from competition GM would be wasting time and money for nothing. I also think LT1 version like 6.2 l v8 with turbochargers (maybe even a different displacement) would be a better choise for premium Cadillac. Also more important question is will GM be able to show this premium v8 as genuine Cadillac engine and not something which is shared with cheaper cars and trucks.

The LT1, for all it's merits, is already over weight. 211 kg vs 183 kg for the LS3 (15% gain in mass). If you switch to DOHC heads the engine gets even heavier (possibly around 240 kg). DOHC heads also make the engine taller and wider. Most importantly though, DOHC heads make the engine less fuel efficient by increasing the internal friction -- four times as many camshafts, twice as many lobes and much greater bearing surfaces in the valve train. As far as the new autos go, they won't arrive for another 2~3 years. Twin turbo 5.5 l,560+ hp, v8 DI DOHC v8 from Mercedes (m 157)- 204 kg 6.2 l v8 DOHC v8 from Mercedes , 570 hp (M159)- around 200 kg. BMW 4.4 v8 DOHC twin turbo DI ,from 400- 550+ hp- around 220 kg Viper v10 8,4 l 640 hp, ohv-around 220 kg Coyote v8, 440 hp, DOHC -around 200 kg Now put a supercharger on the LT1 (i doubt GM will increase displacement on this one) to have competitive HP&torque rating and you have an engine with over 220 kg and more. Now when small block has lost advantage on weight and if i have read correctly it is getting bigger in dimensions too (but still not as big as DOHC competition) ,i think GM should think about special engine for Cadillac premium vehicles. I can see even a coyote v8 with supercharger or twin turbocharger having less weight than a LT1 (LT4).

If GM doesn't offer DOHC v8 (or maybe 3 valve heads on LT version for Cadillac) than this is a least they should offer in premium cadillac model. But i doubt we will see a 7.0 LT version. A 6.2 l supercharger is probably the best and biggest LT GM will have in their LT portfolio.

This LT1 engine weights 465 lbs. Coyote v8 weights 430 lbs. it is also heavier than M156 or M159 engine from Mercedes.

Actually Katech sells even more powerful versions of this engine One with 280 hp and one with 426 hp(this one seems to have direct injection) Katech V4

So your criteria is power and torque.Am i right? To you by default most powerful engine wins (than the engine from SSC ultimate Aero should be better than all of this engine) ? Or is HP per liter also calculated here? Now LS9 has 638 hp and 820 Nm of torque.That is 103,5 hp/l Mclaren 838 has 617 hp( that is 162 hp/l) and 600 Nm of torque M157 from Mercedes -AMG makes 571 (103,8 hp/l) hp and torque of 900 Nm. Now according to yours criterias LS9 engine is better than M838TT (2 wins) and on pair with M157(LS9 has higher HP raiting but lower torque and preety much same Hp/l rating)? Am i getting this right?

I want to see criteria which smk4565 use to determine which engine is better? Fuel consumption doesn't depend only on engine but also on car, transmission etc. Specific fuel consumption is one of the criteria which is in relation to engine only. Just like Weight of the engine/ Hp of the engine. Or physical size of the engine. All this (and much more) can be used as criteria (by individual) to determine why is one engine better than the other. I don't have that much (and more) information to determine which engine is "better". i don't considere type of valvetrain to be criteria..but i know some people who does.

Well i can see DOHC V8 having better image...but ..what else? What is there i can use in real live that DOHC v8 does better than OHV v8? Is coyote v8 better than LS3? Yes, best DOHC v8 engine is maybe better than best V8 OHv (but i'm still interested to know which are criterias) but how much does best DOHC v8 cost? Does GM has car in which they could put that engine and price it accordingly? Also,just to see which criteria do you consider important (i don't mean to be offensive just curious) here is a list of some DOHC engines..which one do you think is(just the engine not the car) better? And why? 5.0 l v8 TT from koenigsegg agera 4.5 l v8 from Ferrari italia 458 M838 TT from Mclaren 6.5 l v12 (L539) from Lamborghini aventador Synergy V8 AMG M159 AMG M157

Do you maybe have any specific data on V8 twin turbo from Mclaren (M838T)? Or Ferrari engine from Italia 458? Graphs for specific fuel consumption, size (for mclaren turbochargers should be included), Co2 emission, price of the engine, etc.? just curious since i can't found those data . I think small block is excellent engine...for corvette...or tucks..or some "cheaper" cars. But if GM ever tries to go in price range of 200 000$+ they will have to offer DOHC..or something totally different with ohv .Like it or not small block doesn't have anywhere near the image of the engine like the uberrev,small displacement engines from competition . Not to mention GM has been experimeting with v8+ size ohc engine in cars (concepts) for couple of decades. There was v12 sohc from sixties then v12 from 1989 concept cadillac solitaire V12 from cien Of course there are V8 DOHC too in this mix. (northstar, LT-5, almost finished ultra V8). In this high price range which i just mentioned (200 000+$),advantages likes price of the engine, weight of the engine, fuel consumption...isn't soo much important .O.K weight is...and image... But you can use expensive but light materials to get weight of the car down (and we are not talking here about big differences..what 10-20 kg in engine weight between LS3 and other more expensive v8).Size ..well i don't have dimensions of Mclaren's or italia's engine but i think GM could make something similar in size with their DOHC v8 if they would want to. Fuel consumption..c'mon we are talking here about 150-200 000+ cars. But...if GM doesn't develope a car in that high price range i don't think they will ever offer or develope any v8 dohc for their lower priced cars..for them (and not just for them) it isn't worth it. But who knows.

Well mercedes 500l(actually it was designed by Ilmor and penske before mercedes took over) was build only so they can use some loophole in the engine rules. There were also one engine which was planned for racing .Brayton V8 LINK And i agree on marketing muscle overpowering mere technicall ability.

Dwightlooi do you really think Mercedes, Porsche, BMW etc can't make engine with cam in block if they want to? I bet they can. Same way GM could make very good DOHC V8, V10, V12 or any other configuration if they want to. To my understanding cam in block engine is cheaper to make, cost less so GM can put engine in cheaper cars (chevrolet ) and can be shared with less expensive trucks etc. Yes both design have their advantages and disadvantages . Also why haven't you put M159 engine instead of M156...or McLaren M838T engine..or V8 engine from ferrari italia? Yes a cam in block V8 engine is more simple design, more compact design, cheaper, etc etc. But it is still loosing battle against DOHC V8 in market around world. Not because one is better or worse. Was bentley 6.75 OHV v8 bad engine? Not to my knowledge. But rumors are GM is still considering special V8 for cadillac flagship..something in the line of engines not being shared with truck .Maybe even DOHC. Also why did GM build Northstar engine if they could use chevrolet small block engine instead, in STS, XLR.? And Ultra V8 DOHC was in plans until crisis hit GM. I don't hear any rumors about Mercedes, Jaguar, BMW, Lexus etc. trying to build cam in block V8, V10 engine? And i also don't think buyers would be to happy if Ferrari put CIB v8 in their cars. And i am betting that you will sooner see Cadillac having DOHC v8 engine in future cars than Mercedes,BMW, Audi having CIB V8 engine in theirs. Yes, let GM built CIB engine for chevrolet, truck etc. But for expensive, luxurie cars... I'm not so sure it is a best choice. Not because it is a bad engine or anything like that. It is more of a image small block from GM have. I do appreciate GM small block engine design..but this is turning in threads like the ones you can read on BMW forums: "My car (engine in this case) is best car (engine) in world. All others don't know how to build proper car (engine).They all suck" etc.