Fuknmovin

iTrader: (1)

Yes I totally agree, I think the reason is that they are already the top of the food chain, why waste your chess moves in the first round....I am sure it is coming, jus only as much as we need to be the best performers out there for the money.

-MOVIN

Tuner@Straightline

I dont know if this was mentioned before, I didn't take the time to read all 33 pages, but the first production motor to exceed the magical 100hp/liter was the BMW M series V12 used in the McLaren F1.

Louie83

iTrader: (3)

Very good post. If everyone understood the first part I made in bold, then people would be able to compromise and agree that there is no one way to make a good engine or single criteria to judge them by.

I also highlighted your last post because it reminded me of something. The NSX, Honda's supercar, does not even make 100 peak bhp / L. Does that make it inferior to the Honda engines that do make 100 peak bhp / L? Heck no, it's a top of the line engine with good torque and hp for it's weight.

hammertime

iTrader: (1)

Excellent! The post the majority of us have been waiting for for 32+ pages. Can we please stop bickering about differences in opinion on OHV/OHC/DOHC and HP/ltr and finally get to the real meat and potatoes of the discussion? Or is it too late?

black_knight

iTrader: (1)

Not my point. I was simply saying the 5.4 was bigger than the 4.6

That's odd, since the last M3 was known for being loud, raspy, and metallic sounding.

So, translation: you're talking out your ***. If I accept your premise that we'll never know the goals, then we can only look at the facts: more hp/L, more weight, more cost, less power. Because this is even possible (and quite frequent, actually), hp/L is a senseless means of comparing the worth of engines.

Yes, to show that such a thing is possible and therefore it is nonsensical to use hp/L to compare the worth of engines.

Maximized displacement for what exactly? Not size/weight obviously! So therefore what does this have to do with my point? Nothing.

Engine builders for displacement limited racing would beg to differ, I imagine. Hp/L is definitely near the top of their lists and for them it actually makes sense - they have an artificial limit on displacement.

Listen, I asked him to rephrase it without using ricer math and he didn't do it. If he was simply asking that, then he has had ample opportunity to simply ask that.

First of all, you danced around nothing. WTF do you think "Specific Output" is? Second of all, that "benchmarking" is precisely what is wrong with this.

As I said,

The engines used as examples of 100 hp/L by the original poster are completely different configurations from the LS series and comparing them to the LS series on a hp/L basis is entirely invalid. There are things about the LS series (cost, weight, size) that give it less hp/L but also make them superior to those "lofty" imports.

To ask "why can't we make 100 hp/L like the imports" is senseless. The answer is: because we don't want to get the bad things that come with configuring your engine to make hp/L instead of hp per size/weight/cost."

It's the "like the imports do" part that is messing this up. If we made power "like the imports do" then the LS series would suck "like the imports do." Understand that there are very good reasons that the LS series is not like the imports - things that make them superior to the imports. Sure, they make less hp/L, but what would you rather have? Hp/L or the stuff that makes the car actually go?

This isn't mere semantics. This isn't a matter of my getting on his case for using a word or two wrong. These are some very bad premises. The question could be made valid but the poster has so far refused to do that. Based on his first three replies (which completely missed my point; rephrasing to hp/cubic inch, and then rephrasing to "specific output") I don't think he is really listening and utterly refuses to even consider the idea that he may have done something wrong.

I offered several times to do just that but every single time the original poster has brought the ricer math back into it and insisted he did nothing wrong.

black_knight

iTrader: (1)

Exactly so. Simple point I've been trying to make is that of the things you can do with hp/L, using it to compare the worth of engines is not one of them. It does not in any way tell you which engine is better.

And saying that it will tell you the better engine if the displacements are equal is silly. Equal displacements cancels the displacement out of the equation.

engineermike

Well no friggin crap. You could have pointed out that the 5.4 deck height is 1.14" taller due to small 3.937 bore spacing about 4 pages ago.

Yea, you're right. After producing that thing they probably just throw NVH out the window for all future designs also. [/sarcasm]

Okay, so let me get this straight: You claim to KNOW that hp/liter was BMW's chief design goal with this 4.0 v-8. I claim that you and I don't know what exactly the design goals were, but the main goal was certinly not hp/liter, and I'M the one talking out of MY ***???

Let's see, I think we've been through this already. . . but more hp/l = not necessarily more weight (AMG 6.2), not necessarily more cost (countless examples, for chrissake the LS7 has a bunch of Titanium parts and CNC head porting), and not necessarily less power (countless examples, like the Porsche M80). I like how your "facts" aren't really "facts" at all.

You picked the BMW V-8 to show that it's possible to make a high hp/liter engine heavy? Well it's possible to make ANYTHING heavy! Re-arrange the design goals of a sport bike or ZO6 and we could make those heavy too! Your whole point is that you could find some heavy high hp/liter engine, so therefore hp/liter is an invalid metric. I could find an engine with good flowing cylinder heads, but doesn't make any power, so does that make head flow an invalid metric? I could find high hp engines that weighs 2 tons, but does that mean hp is also an invalid metric? I'd like to see you start trying to tell people that "Hp is not a valid discussion because it doesn't tell you the worth of an engine. They build lots of very heavy high hp engines that are worthless for racing, therefore hp is ricer math and should not be used to compare the worth of engines."

So allegedly BMW maximized hp/liter for what exactly? Not size/weight obviously! So therefore (by your own logic), it should also have nothing to do with your point either. You show me a high hp/liter small displacement engine that's heavy and I'll show you a low hp/liter large displacement engine that's heavier. Something tells me there's more of the latter than the former.

Pick an engine that increased hp/liter with the goal of decreasing size/weight and then you're on a fair playing field. Oh, but wait, the LSx loses then, and we can't have THAT on THIS website. . .

So, you believe the engine builders for displacement limited racing, as well as BMW v-8 designers both design engines solely for hp/liter, but somehow BMW makes them heavy and the race engine builders make them light. You don't think that BMW could have built a light engine if they wanted to? Do you think that their engineering staff is incapable of building a lighter engine like the AMG folks did? You can use available high hp/liter technology to make an engine lighter and more powerful than 2v and pushrod technology, but it's not always used that way.

His original question pretty easy to follow and made sense. I'm starting to wonder if you're trying to distract everyone from the original quesiton because you have no idea how to answer it. I've asked you this question at least 3 times and you seem to dodge it every time:

"As I already posted, the thread originator simply wanted to know if we could achieve 570 hp and keep stock-like driving characteristics from the LS1. He knew, by benchmarking the Japs and Germans, that the specific output had been achieved with other designs and simply wanted to discuss if it was possible with the LS1.

Once again, my answer to this question is to find a production engine that makes alot of power using a 2v head, scale it based on displacement (this is where hp/liter comes into play), then adjust it based on piston speed limitations. Again, I ask you black_knight, how would you go about answering this question and what is wrong with my approach?" -engineermike

. . . which is precisely why he created the thread. He probably wasn't aware of some of the high hp/liter 2v engines out there, like the Seca 600, which is over 100 hp/liter.

If the imports achieved 100 hp/liter with a 2v cylinder head, then is it too much to ask if we can get there with the LSx while retaining the 2v head? This is where benchmarking comes in. Find an engine with a similar layout to the LSx and see what specific output it makes, then you know what the limit is without applying something like DOHC. Would all those "bad things" that you claim come with DOHC automatically come with the higher hp/liter then?

I really think you're just a die-hard LSx guy that doesn't want to believe that there is something better out there, and are highly offended by anyone insinuating that import or Ford technology may be superior. One thing that you can not deny is that high hp/liter is indicative of an engine that has a well tuned and high flow induction and exhaust system. Am I the only one impressed by a highly developed and effective induction and exhaust system?

If you were to take the technology that the imports use to achieve high hp/liter, then apply to an engine with alot of liters (LSx), then what do you wind up with? Alot of horsepower, which IS the stuff that makes the car actually go, and the crux of the thread! We don't have to all switch to 4-bangers to enjoy higher hp/liter.

YOU have ridiculed any conversation about how to increase the hp/liter of the LSx. Again, if you don't like talking about "ricer math", the no one is forcing you to. You could discuss methods to achieve 570 hp from 5.7 liters (if you chose to phrase it that way). Or, you could just refrain participation if you don't like the discussion.

Do we go into your threads and tell you that you asked the wrong question?

Mike

IWantAnA6

actually torque is the stuff that makes the car go and horsepower is a function of that. Dynometers specifically measure torque and engine rotational speed and horsepower is calculated from their findings. When talking about engines and their worth it's important to know that horsepower marks the highest possible output from the engine in a single instance. Torque is similar except that this measurement is 80% true for the rest of the useable revline - at least for LSX motors anyway.

In real life, the '98-on-down v8 mustang made a bit more horsepower than the 96-02 f-bodies of that time, which means that a race would be close, but the 'stang should just barely edge me out, right? Well no because mustangs made back the have a 68 ft-lb advantage in torque over me, so I've got no chance. With a Civic Si, nothing changes, except the increase in distance between my car and his. Even with 100 hp/L, That's not a race. That's not even an argument.

Quick Double Nickel

iTrader: (5)

engineermike has hit all my points exactly. I posted a simple question on how we can achieve 570 horsepower from 5.7L. I used the examples of the import engines not because it's an apples to oranges comparison with regards to engine design and layout, but because, frankly, I know of no other comparable engine that does it. Is there a pushrod, 2 valves per cylinder, production engine that we can compare the LSx to besides the new Hemi? If there is, please let me know. Also, I think that it's pretty pathetic that we have to limit a comparison of an engine to a domestic counterpart. Just because a different manufacturer chose to take a different route to obtaining power than the beloved pushrod engine, doesn't automatically disqualify them from outperforming the LSx engine in several categories, or warrant them being called a "ricer". I'm pretty impressed with Toyota's new 5.7L V8 with 380 horsepower and 400 lb-ft of torque. Sure it's DOHC, and it may way more than an equivalent displacement LSx engine (maybe it doesn't), but do you think that matters to 99% of the people who buy these things? Buyers like it because it has got great horsepower and torque for its displacement and gets good gas mileage while maintaining low levels of NVH and has a ULEV II emissions rating.

Now, I know that looking strictly at a specific output from an engine in no way defines its entire potential or its ability to move a vehicle. But, the good thing about large displacement engines is that even in a situation where an engine is tuned for maximum horsepower, there is usually a good amount of torque also being produced, so it's a win-win situation. There is no way a 6.0L engine that has 600hp will have a maximum torque reading in the 200 lb-ft range, even if the engine is DOHC and reaches peak horsepower at 7,000rpm. If that engine was tuned to make 1200hp NA then maybe it would only make 200 lb-ft, but most likely it would still make more.

engineermike

Man, I wish you didn't bring that up. This is a freakin' embarrassment for Chevrolet:

2007 Tundra 4x4 crew cab (5.7 liter DOHC) versus 2007 Chevy 4x4 crew cab (6.0 liter pushrod)

Cost: $41,494 vs. $41,054
Weight: 5,637 lb vs. 5,457 lb
Power rating: 381 hp vs. 367 hp
Torque rating: 401 ft-lb vs. 375 ft-lb
rwhp: 320 rwhp vs. 295 rwhp
test average gas mileage: 14.4 mpg vs. 12.7 mpg
Quarter mile: 14.8 @ 94 mph vs. 15.5 @ 88 mph

source:
http://www.edmunds.com/insideline/do...ticleId=119281

I really shouldn't have brought this up, though, as it's part of the defense of DOHC and that debate was already over.

Mike

black_knight

iTrader: (1)

It doesn't have to necessarily be more weight. The point is that since different engine configurations can fit different amounts of displacement, then it is senseless to compare engines on the basis of hp/L and say that this one is better than that one because of hp/L. It doesn't have to necessarily be the case; it only has to be possible and not totally rare.

So what? The point is that a bigger displacement does not mean a bigger engine. That is the only point I need to make and it is eminently true.

Well obviously they didn't do it. So either they couldn't do it or they were being idiots. Either way, one thing they were trying to do was limit displacement. I know you don't believe that, but a 5 liter V10 is a displacement-limited engine. That's a small displacement for a v10. So either way, they set hp/L as a higher priority. So either way they sucked and it was because of hp/L.

Sure, if you ignore the part I focused on in my last posts. I simply refuse to ignore that error until he withdraws it. After that, feel free to discuss away.

I'm not interested in that question. As I said, my criticism of hp/L is when it is used to say "this engine is better than that engine." To say that because imports get better hp/L then we should be more like them. As I have told you several times now, I don't care if you use it to guesstimate the effects of changes on engines that have very similar configurations. I don't know why you think I'm dodging since I told that to you several times.

I'd say comparing the VVT gains from the LS3 vs LS2 and extrapolating that out to the LS7 would be valid, so long as you put the caveat out there that it's only a guess. You have to be careful with this kind of guess, though; you can't compare any two engines just because they're both 2v.

And one thing you definitely shouldn't do is compare two engines of totally different architecture, such as OHC vs pushrod. You can't just "apply" the former to the latter, you're basically talking a total redesign where you might compromise some integral parts of the engine (such as its light weight and compactness, for example)

Yes, but he only wanted to know that because he benchmarked the imports and thought that since they do it why can't we. And I'm saying that benchmarking different configuration engines on the basis of hp/L is not sensible. The engines he's talking about may have "achieved" 100 hp/L but they did so in ways that we would not want applied to the LS series. As I said, the LS series has less hp/L for very good reasons; reasons which make them superior to the small-displacement imports. I just don't see the sense in taking inferior engines and saying "why can't we be more like that?"

And I say no it is not. Or at least, you wouldn't want to do so. Because sometimes specific output comes at the cost of other things... more important things. Things you don't want to compromise.

There are you happy? I'm answering the question. But my point remains that the question has an invalid premise behind it (that you can just outright compare unalike engines on the basis of hp/L).

It depends on the engine. How different is it from the LS series? Would making the LS series like it be easily done or would it compromise the advantages of the LS design? Also, would it cost a ton when we could just as easily up the displacement? Questions like that need to be asked.

For the displacement, you mean. You can't just throw a "well tuned" honda head on an LS1 and expect it to work (pretending that it would fit). You can't even "scale up" said head and expect it to work. Things that work on small engines don't necessarily work on large ones. If you happened to be a master engineer who had extensively studied both designs, you might be qualified to say whether the one had anything that could be applied to the other. Otherwise, you're just talking out your ***.

For instance, something that is easy to do with small, light valves might be impossible to do with big, heavy valves. Take CVT transmissions, for instance: they work pretty well for low power engines. But scale one up to work on a high-power engine and then it becomes so heavy that you lose any advantage you would have gained and then some. Hell, on top of that there are economies of scale. Something that is relatively cheap to do for a small engine might be prohibitively expensive to do for a large one. There are a million considerations like this which mean you can't simply say that a 4.0 German engine makes 100+ hp/L and our LS series doesn't so why don't we do like the Germans and then we'll make 570 hp?!?

And that's without even bringing up the fact that the 4.0 German mill is heavier than the LS7 is at 7 liters.

I disagree that it means they are "highly developed and effective." Effective means it makes the car go. I would say they are comparatively developed, that is, for the displacement. In other words, if they don't have the displacement to back it up then it all amounts to a hill of beans.

I don't tend to be impressed by a "highly developed and effective induction and exhaust system" that is so big and heavy that it eliminates the whole point, which is making the car go. Impressive is when you can swap an engine out into another car and it will actually make it go faster. That is why the MB engine is far more impressive to me than the BMW.

The reason is because I care more about the end result of what works in reality than how "impressive" something is on paper. It's like cars that are total dyno queens but don't knock down good quarter mile times. Some people are impressed by that. Not me.

Likely, you end up with crap. Because it doesn't work that way.

There, I have given more than enough detail. My objection is not some kind of knee-jerk, thoughtless categorical reflex to a mention of "hp/L." The original question, as asked, is invalid. It contains faulty assumptions. Trying to answer it, as asked, would be impossible.

So, once again and after due consideration...



Not as a knock against anyone, as such, but because the entire premise of this thread is invalid. The question is flawed so as to be unanswerable. What answer, as such, is possible, I have given. Enough is enough!

B T

As I already posted, the thread originator simply wanted to know if we could achieve 570 hp and keep stock-like driving characteristics from the LS1.

>>>
lol

B T

As I already said, the turbo 'busa motor was simply a convenient example since it has the same hp as an LS1 but less torque. ....the example really had nothing to do with a turbo 'busa engine. It simply used that engine as an example because it made the same hp as an LS1 but with less torque.
>>>

black_knight

iTrader: (1)

Interesting:

I don't see NVH there.

mzoomora

iTrader: (36)

And yet the 6.2l is the highest output engine in its class, and the Toyota engine is snapping camshafts.
Not really an embarrassment at all, the only bad thing is that GM didnt have 6.2l production at full speed and could only offer it in the Denali, but that will be corrected next year.

IWantAnA6

Why would you want to limit yourself to 100hp/L on the LSX anyway? Thats only about 570~600hp, depending on which displacement you choose. We've got FI people on this board that have already exceeded that and GM's New block (The LSX) is good for 2,500 hp (Good luck getting there on pump gas though...)

If 100hp/L is good, then certainly 2-300hp/L would be even better, right? On such a great engine, stopping at *just* 100hp/L is a waste of potential.

engineermike

Well don't claim that it is, "facts: more hp/L, more weight," if it's not necessarily more weight.

. . . and higher hp/liter does not mean a bigger engine also.

So you honestly think that the BMW engineers were not smart enough to make their engines lighter, or "they were being idiots"? Or is it possible that the goal was NOT to make a light weight engine. My bet is that weight was not a primary goal. Or maybe you could go over to Germany and teach those "idiots" a few things about engine design. . . er. . . not.

So, by that logic, then the Ferrari 365, with its 355 hp 4.4 liter v-12 40 years ago was also displacement-limited? Define "displacement-limited". Nevermind, that's neither here nor there.

What makes you think that hp/liter was the primary goal? You've been harping on this all along, so I would like to know where you got that from. And, besides, I thought you decided earlier that, since BMW didn't try to build a light-weight high hp/liter engine that it wasn't a valid part of the discussion. (Remember when I pointed out a very heavy, maximized displacement engine with low hp/liter and you said it they didn't try to make it light, so it wasn't comparable? ... or does that rule only apply when it works in your favor?)

Well if you're not interested in the original question in the original post, then why are you still here?

Okay, so you will allow me to use "ricer math" to figure out what the max hp is of the LSx architecture and determine what needs to be done to get there. However, you will not allow the original poster to use benchmarking of import designs to determine what the max hp is of the LSx architechture and determine what needs to be done to get there. That's not a fine line - it's no line at all.

You're dodging it because you never actually answered it.

If you find an OHC 2v engine making your specific output goals, then you most certainly can mimic it's port geometry and valve timing on a pushrod 2v motor.

Okay, so instead of saying "hp/liter is ricer math" for 33 pages, perhaps you can find some examples of engines with similar configurations to the LSx but higher hp/liter. Determine for yourself if the technology is something you would want on the LSx. That way we can better learn from other technology that's out there and something constructive can come out of this rather than incessantly repeating "hp/liter is ricer math" and demanding that quickdoublenickel apologize and rephrase his question. Maybe he chose some poor comparison engines since the architecture is so different (though he didn't demand that we compare to the Civic Si and Audi 4.2 - he just said that they "come to mind"). This is where others can come in and point out some valid comparisons and if the technology is applicable to the LSx platform.

So you say that reaching 570 hp from 5.7 liters using a big cam and big heads is perfectly acceptable, but achieving 570 hp from 5.7 liters while keeping stock driving characteristics will "cost...things we don't want to compromise"???

I guess I missed the answer. . . the question was (for the Xth time) "How do you achieve 570 hp from a 5.7 liter LSx and keep stock-like driving characteristics?" What's your answer again?

THAT'S EXACTLY THE DISCUSSION THAT NEEDS TO TAKE PLACE!!!! I'd LOVE to talk about those very things rather than defend the use of benchmarking specific output for 33 pages.

Well no crap, and that gets into the nuts-and-bolts of it - the technical discussion that should be taking place rather than 33 pages of "hp/liter is ricer math". This is the Advanced Tech section, isn't it?

I thought that we already determined that an induction and exhaust system doesn't have to be big and heavy in order to out-do the LSx stuff. Do you remember the AMG engine that's lighter than the LS7, matches the hp, and gets it from only 6.2 liters?

So, again, you're saying that we should continue to put big lumpy cams in our LSx's to get 570 hp from 5.7 liters and not even consider trying to increase hp/liter using other methods, because the other methods will leave you with "crap"?

You gotta' be kidding me. What a sucker for marketing! I don't see reduced weight or higher hp/liter on there either! Do you honestly think that those are the only goals in the engine design??? What about emissions? What about cost? OMG you are hilarious!

Mike

WizeAss

iTrader: (5)

Erik, you are right on the money.... stock Porshe Engine with all the bells and whistles... vs a LS2 block going in the same car. hmmmmmm To make power seems like those German's and Euro fellas have to add losts of size without the displacement!



looks like he now has room to put a turbo in there... and beat up on some TT 911's??

engineermike

Hey do you think you could find a picture of the porsche engine stripped down to the bare long block also? That thing has the fan, ac compressor, air intake piping, even the muffler! You can't even see the Porsche long-block! Of course the LS1 long-block is smaller.

Mike

black_knight

iTrader: (1)

I've explained the flaws in the original question. The benchmarking is all wrong. Even Engineermike, in a sideways fashion, is admitting this. It is not Engineermike who needs to rephrase the question, however. The original poster needs to understand his incorrect assumptions and misuse of benchmarking. (i.e. ricer math)

I'm not too hopeful of that, though. If he was prepared to actually listen and consider the possibility that he might have done something wrong, I would think he would have done it by now.