[doc7000]

LT1 drops off where it drops off because they were going for about 460BHP, if they kept it going strong it would have broken 500BHP.

Though the Gen V AFM system is an improvement as it seems over the Gen 4 AFM system, the L99 engine was very limited. However LPE runs AFM up to 550BHP on the LT1 engine...

A lot of people seem to think that whenever automakers produce an engine that they try to get as much horsepower as possible everytime. Which just isn't the case, and it isn't the case for many different reasons......

This is partly why people go to the after market (and the LT1 has a ton of power left on the table). It is also why you can buy a LS3 crate engine from GM with 525BHP.....

[Noob]

Originally Posted by KMPrenger

100%

I don't even know why there are complaints here. The LT1 rocks in the power department. Yes...TQ drops off a bit at a certain range, but the power curve is still much better than the LS3, and also much better than the 5.0 for my preference, not that I think the 5.0 is a bad engine at all.

But its two much different ways to achieve an outcome. the HP per liter argument is completely irrelevant when it comes to comparing these two types of engines. Its apples and oranges. Stupid argument for sure.

Also, its not like GM can't build a great DOHC engine...look at the V6 engines. Spectacular DOHC engines with as much or more tech in them than the 5.0. The LGX makes over 93hp/l. That's more power dense than the Coyote engine.

We've all seen how great the LT1 performs in the Corvette, and if one does decide to modify it, it will push 500HP easily with some bolt ons and a tune.
No complaints here.

hm, I would rather have a 6.2ltr. DOHC with 84.6hp/ltr. in that 2016 Camaro instead of "only" 74,2hp/ltr. due to old 2valves/1cam design.
My brothers AMG C63 is that engine which cranks out 525hp in his 2009 Mercedes. It revs 7200rpm and was "engine of the year" 2 times.
It weighs 439lbs.....i read.
http://mbworld.org/forums/w211-amg/2...ne-weight.html

Perhaps Chevy know the selling numbers of V8´s will fall as tax and gas prices increase. So they decide not to spend mch more money in further developing of a given and surely proofed design. A direct fuel injection is a small intervention adn cyl..deactivation helps saving fuel on an old design which normally drink 1-2ltr more per 100km compared to a newer design with less capacity but equal hp.

[doc7000]

Originally Posted by Noob

hm, I would rather have a 6.2ltr. DOHC with 84.6hp/ltr. in that 2016 Camaro instead of "only" 74,2hp/ltr. due to old 2valves/1cam design.
My brothers AMG C63 is that engine which cranks out 525hp in his 2009 Mercedes. It revs 7200rpm and was "engine of the year" 2 times.
It weighs 439lbs.....i read.
http://mbworld.org/forums/w211-amg/2...ne-weight.html

Perhaps Chevy know the selling numbers of V8´s will fall as tax and gas prices increase. So they decide not to spend mch more money in further developing of a given and surely proofed design. A direct fuel injection is a small intervention adn cyl..deactivation helps saving fuel on an old design which normally drink 1-2ltr more per 100km compared to a newer design with less capacity but equal hp.

The engine weights that most automakers put out are not comparable unless they state what is on the engine when it weighs that much. That Mercedes engine isn't fully dressed at 439 pounds.....

I think it is funny the assumption that if the LS3 for example was DOHC that GM would have tuned it for more horsepower, when in reality they wouldn't. You can buy a GM crate LS3 engine for less then $10,000 that produces 525BHP if you really want to compare the Mercedes 6.2L vs GMs 6.2L LS3 engine (and that is without VVT).

[ULTRAZLS1]

Originally Posted by Blackdevil77

I would consider those modifications that don't require tuning if they really show an improvement in 1/4 mile times/trap speeds and the extra power can be felt. If the gains are something that only a dyno would see, then I wouldn't bother. Now if I was loaded rich and bought 2 Camaro's, one would stay stock and the other would probably get cammed with long tubes, off road x-pipe, intake, etc.

15-20 hp is slightly noticeable. I bet if you did TB, pulley and cai all at once you would notice. Those mods are also easy to do ( the pulley can be a bit tough depending on tools etc) and fairly cheap. Pulley with new belts and bolt is around 350 bucks depending on brand ( u can pay a lot more for some). Same with cai. TB porting is 150 I think. So 850 bucks for about 20 hp and retained warranty... And easy install should not have to pay labor do it yourself. And I'm talking honest hp not what companies claim.

Those mods along with a cat back is what I did with my 2010 during the first 2 years 20k miles or so. Then it's on lol

[SpeedIsLife]

I think it's a bit silly to think that 460HP was the target they were always aiming for.

The LT1 in stock form is the very conservative balance chosen by GM of fuel economy, long term durability, reliability and able to run lower grade fuels if needed.

It looks like the majority of the difference in power is from the bump in the CR and DI as well as VVT. It's a great motor but also was obviously meant to be done by the low 6,000 range.

Making more power isn't as simple as throwing in a hotter cam at the OE level. It has to be totally recertified, tested, pass cold start emissions, etc. CAFE isn't going away or getting easier and it absolutely will not shock me if within this 6th Generation we see the V8 phased out below a Z** level car.

[ULTRAZLS1]

Originally Posted by LesserO2Evils

Haha! Nice try! You are SCREWED, JACK!!!
(Prompted internal monologue unfolding..."Hmm...'screwed'... I wonder if an Eforce or KB would fit under the stock hood? If I did that, I wouldnt have to worry about emissions compliance and wouldn't be nickled and dimed with 3/4hp here and there... I coukd get the Hp level I want in one fowl swoop!! Maybe I should consider THIS route, this time? It would still DRIVE LIKE STOCK?"

I've thought the same.

I just hate the extra weight on the nose, not being familiar with FI and the very large investment all at once. And believe it or not my NA builds have always ran with mild supercharged only set ups on comparable cars etc.

Tough choices...

[ULTRAZLS1]

Originally Posted by Noob

hm, I would rather have a 6.2ltr. DOHC with 84.6hp/ltr. in that 2016 Camaro instead of "only" 74,2hp/ltr. due to old 2valves/1cam design.
My brothers AMG C63 is that engine which cranks out 525hp in his 2009 Mercedes. It revs 7200rpm and was "engine of the year" 2 times.
It weighs 439lbs.....i read.
http://mbworld.org/forums/w211-amg/2...ne-weight.html

Perhaps Chevy know the selling numbers of V8´s will fall as tax and gas prices increase. So they decide not to spend mch more money in further developing of a given and surely proofed design. A direct fuel injection is a small intervention adn cyl..deactivation helps saving fuel on an old design which normally drink 1-2ltr more per 100km compared to a newer design with less capacity but equal hp.

You do know that ford stays around 5 liters for a reason right?

They don't do it for fun or for the challenge. Or to give the fans something to brag about. The design is limited to around 330 cubes I think. The 6.2 in the trucks is a sohc 16 valve. Different motor completely.

Also... OHV ( pushrods ) design is actually a few years newer than DOHC. Even Fords new flat plane crank design/motor has been around since the beginning of the 1900s from Cadillac I believe.

I love the design and layout of a pushrod motor. The relative simplicity. Far easier to work on for the shop rat like myself. MASSIVE gains from a cam and you are only changing one for less cost, time and effort.

[doc7000]

Car makers have targets when they are designing performance cars....

They don't slap together an engine and see how much power they can get from it and move on from there....

The C6 Z06 was first planned to produce 450BHP, as during its development that is what the Viper was making. It was planned to have a 6.4L 450BHP engine, then they changed that when the Viper was shown to have 500BHP to produce 500BHP. Yes 500BHP was their goal when they produced the C6 Z06, however that wasn't their only target for said engine. There was a price target set for the C6 Z06 as well (the car launched at $65,000 starting MSRP). The car also had fuel economy goals for it as well, so yes when they start a vehicle program that have targets and they try to hit all of their targets.

When the C7 was in development they were probably looking for about 450BHP, they were also looking at being able to get 30+MPG on the highway. The engine needed to have a certain amount of refinement and street-ability, so yes GM targeting 450-460BHP for the C7 isn't silly it is exactly how things work in the auto industry.

It is on internet forums and arm chair racers where it becomes a point of pride and dick measuring where we think that they have tried to get every ounce of power from their engine.

Notice that the Mercedes 6.2L engine isn't producing 100BHP/L or higher....... infact in some trim levels it produced less then 500BHP why? because that was their target for the program at the end of the day. This isn't actually just US automakers that produce low range engine in performance vehicles. Hell the Zonda use to pack a Mercedes sourced 7.3L DOHC V-12 engine that produced 550BHP.

The real big change here is Ford Voodoo engine as US automakers generally never aim for such high rpm engines since the 1960s.

Want more examples of this?

If you look through the 1990s and 2000s when Ford went with a SOHC/DOHC GMs OHV 2 valve engine produces more BHP/L why? because that is what their targets were. Not the BHP/L but power output and they were using a 5.7L engine. Ford example the 4.6L DOHC Cobra engine produce 320BHP (after recall) from 4.6L (or 70BHP/L) and the LS1 produced 305BHP from 5.7L (or 71BHP/L).

My point is that there are many factors in what these engines are producing not just one....

[Noob]

@doc7000
i agree, but certainly there must be a reason why most engines have DOHC with VVT on both cams. I can live with that old pushrod truck engine (haha, sry...) but wished that AMG 6.2 in it

[SpeedIsLife]

Originally Posted by ULTRAZLS1

You do know that ford stays around 5 liters for a reason right?

They don't do it for fun or for the challenge. Or to give the fans something to brag about. The design is limited to around 330 cubes I think. The 6.2 in the trucks is a sohc 16 valve. Different motor completely.

Also... OHV ( pushrods ) design is actually a few years newer than DOHC. Even Fords new flat plane crank design/motor has been around since the beginning of the 1900s from Cadillac I believe.

I love the design and layout of a pushrod motor. The relative simplicity. Far easier to work on for the shop rat like myself. MASSIVE gains from a cam and you are only changing one for less cost, time and effort.

I think the design is limited due to the bore spacing to allow it to be built on existing lines at the Romeo plant

[doc7000]

Originally Posted by SpeedIsLife

I think the design is limited due to the bore spacing to allow it to be built on existing lines at the Romeo plant

That was the huge compromise when they came out with the 5.0 Coyote engine, they use a pretty small bore spacing so to get displacements really over 5.2L of the Voodoo engine they would have to use a stroke that wouldn't allow 8,250rpms. Actually the Voodoo should make more then 526BHP considering how that engine is tuned, Ford needs a new engine with larger bore center spacings.

[SuperSound]

Originally Posted by Noob

@doc7000
i agree, but certainly there must be a reason why most engines have DOHC with VVT on both cams. I can live with that old pushrod truck engine (haha, sry...) but wished that AMG 6.2 in it

There is, it's called Fuel Efficiency and Emissions. The larger the displacement the more emissions the engine outputs and generally lower FE. You can develop technologies (like VVT, DOD, DI) to improve this of course, but OHC designs benefit from the same tech too. OHC engines are physically bigger and heavier than a similar displacement OHV engine, so engineers have to pick one over the other for most applications. OHV are cheaper to produce too. In the end, the difference can be summed up as:

Cheaper, smaller size, less weight, worse FE/Emissions - OHV
More expensive, lower displacement, better FE/Emissions - OHC

This is definitely a simplification, but I think represents the main points. In Europe FE/Emissions has been a bigger driving force for engine development than in the US. In the US, people really didn't focus on FE until gas hit $4 a gallon. The price in Europe has been higher than that for decades. So OHV died out quicker there than in the US, because it wasn't as big a priority, particularly in the V8 market for trucks and performance cars. Couple that with taxes on displacement in Europe and you have your answer as to why all you see is OHC engines.

[Blackdevil77]

One thing I'm slightly confused on, why do I keep hearing the LT1 referred to as a truck engine? Did I miss something?

[doc7000]

Originally Posted by Noob

@doc7000
i agree, but certainly there must be a reason why most engines have DOHC with VVT on both cams. I can live with that old pushrod truck engine (haha, sry...) but wished that AMG 6.2 in it

I think it is funny as most pickup trucks built today are built with DOHC engines......

Technical limitations at the time (1970s) and the fact that small engine (small bore engines) really favor 2 or 3 intake valves over 1 intake valve. During the 1970s big engines really died off and were replaced by smaller engines, this carried through the 1980s and early 1990s.

VVT was more about improving fuel economy along with low and mid range torque in multi valve head engines. We are at a point in time where really all of these engines are really strong and good engines. BTW GM OHV engines have gotten plenty of engine of the year award and their LS7R engine got motorsports engine of the year in Europe.

It just isn't the 1980s anymore where you had a 600 pound 205BHP V-8 engine in a Corvette.... . Remember the N/A DOHC engines weren't great on horsepower then either (sure they were better then that Corvette engine but a hamster is barely worse then that engine). Turbocharged engines were king, it was the era of the Porsche 930 with its 3.0L and 3.3L turbocharged flat 6 in the Porsche 911. The Ferrari F40 used a turbocharged engine, the Porsche 959 used a turbocharged engine. Hell one of my favorite cars the Jaguar XJ220 used a twin turbo V-6 engine instead of a planned N/A V-12 engine. We also had the sledgehammer Corvette which made 880BHP from twin turbos........