100 horsepower per liter naturally aspirated
#41
Originally Posted by LSGunZ28
I still dont understand why we dont use variable valve timing in our cars, cant engineers think of something? even though its a in block cam.
#42
Originally Posted by FieroZ34
And since, in inlines, size is related to displacement, HP/L becomes a VERY important figure.
Since that is what you actually mean, then why have the BS middleman?
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Originally Posted by FieroZ34
Did you even read what I wrote?
My point wasn't that HP/L is important, it's that it is in sportbikes, where power required from a given weight/size is of the utmost in importance. And since, in inlines, size is related to displacement, HP/L becomes a VERY important figure.
My point wasn't that HP/L is important, it's that it is in sportbikes, where power required from a given weight/size is of the utmost in importance. And since, in inlines, size is related to displacement, HP/L becomes a VERY important figure.
also you are comparing sportbokes with LSX engines. Its different, LSX engines go in sport cars, not bikes.
I dont doubt your knowledge, but Im just sayin'
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Originally Posted by black_knight
The newest LSx family engines do. The L92 has VVT. The reason why not before is because it wasn't needed: they spent their research $$$ on improving head flow and intake design and it did the trick pretty well I'd say.
#45
Originally Posted by LSGunZ28
so do they have a single cam that changes lobes/lobe location on the shaft? or actual 2 cams that switch lifters?
Variable valve timing
Variable valve timing (VVT) is a standard feature on 6.0L and 6.2L engines; it helps optimize camshaft timing to improve low-rpm torque and high-rpm horsepower. The introduction of variable valve timing through the unique dual-equal cam phaser is the industry’s first application of VVT on a mass-produced V-8 cam-in-block engine. The unique dual-equal phaser adjusts the camshaft timing at the same rate for both the intake and exhaust valves.
The system incorporates a vane-type camshaft phaser that changes the angular orientation of the camshaft, thereby adjusting the timing of the intake and exhaust valves to optimize performance and economy, and help lower emissions. It offers infinitely variable valve timing in relation to the crankshaft. The cam phaser vane is attached to the camshaft on the front journal. As driving conditions warrant, the cam phaser system can reduce ignition timing at higher rpm levels to increase power. At lower rpm levels, torque is enhanced with increased timing.
This cam phaser feature was pioneered by GM and introduced on the new 3.5L and 3.9L V-6 engines in 2005 – a first for the use of variable valve timing on a cam-in-block engine design. As driving conditions warrant, the cam phasing system can reduce ignition timing at higher rpm levels to increase power. At lower rpm levels, torque is enhanced with increased timing.
Precise camshaft timing is the key to the variable valve timing system’s capability to optimize performance. Like the 58X ignition system, cam phasing is directed by the E38 ECM. It relies on data from a camshaft position sensor – a target ring with four equally spaced segments – that communicates the camshaft’s position quicker and more accurately than previous systems that used just a single segment. Also, a leaf spring-type tensioner is used on the timing chain to ensure precise tension.
The aluminum-block 6.0L version uses variable valve timing in conjunction with Displacement On Demand technology to bolster fuel economy. With cam phasing, Displacement On Demand technology allows the engine to run longer in fuel-saving four-cylinder mode, while producing instant V-8 power and response as soon as the driver calls for it.
Variable valve timing (VVT) is a standard feature on 6.0L and 6.2L engines; it helps optimize camshaft timing to improve low-rpm torque and high-rpm horsepower. The introduction of variable valve timing through the unique dual-equal cam phaser is the industry’s first application of VVT on a mass-produced V-8 cam-in-block engine. The unique dual-equal phaser adjusts the camshaft timing at the same rate for both the intake and exhaust valves.
The system incorporates a vane-type camshaft phaser that changes the angular orientation of the camshaft, thereby adjusting the timing of the intake and exhaust valves to optimize performance and economy, and help lower emissions. It offers infinitely variable valve timing in relation to the crankshaft. The cam phaser vane is attached to the camshaft on the front journal. As driving conditions warrant, the cam phaser system can reduce ignition timing at higher rpm levels to increase power. At lower rpm levels, torque is enhanced with increased timing.
This cam phaser feature was pioneered by GM and introduced on the new 3.5L and 3.9L V-6 engines in 2005 – a first for the use of variable valve timing on a cam-in-block engine design. As driving conditions warrant, the cam phasing system can reduce ignition timing at higher rpm levels to increase power. At lower rpm levels, torque is enhanced with increased timing.
Precise camshaft timing is the key to the variable valve timing system’s capability to optimize performance. Like the 58X ignition system, cam phasing is directed by the E38 ECM. It relies on data from a camshaft position sensor – a target ring with four equally spaced segments – that communicates the camshaft’s position quicker and more accurately than previous systems that used just a single segment. Also, a leaf spring-type tensioner is used on the timing chain to ensure precise tension.
The aluminum-block 6.0L version uses variable valve timing in conjunction with Displacement On Demand technology to bolster fuel economy. With cam phasing, Displacement On Demand technology allows the engine to run longer in fuel-saving four-cylinder mode, while producing instant V-8 power and response as soon as the driver calls for it.
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Originally Posted by black_knight
Some corrections, here:
Excuse me but what does size and weight have to do with LITERS? Nothing. Don't compare power per liters, compare power per size/weight.
Excuse me but what does size and weight have to do with LITERS? Nothing. Don't compare power per liters, compare power per size/weight.
Obviously, the pushrod designs don't provide physically smaller packaging in bike style engines. I would suppose this is because there aren't enough cylinders for it to "pay off." Maybe an engineer can correct me if I'm wrong.
But the bottom line is still that "liters" as such is not relevant.
No, that's simply not true. There's a reason they don't make inline, DOHC 8 cylinder engines: they're huge. Also inline engines are quite heavy when compare to vee configured ones of the pushrod or OHC variety, at least once you go beyond 4 cylinders. Check out the weight of BMW's inline 6 on the old M3: it weighed more than an LS1, I think.
You're right, the M3 engine does weigh more than the LS1. That's because it's made out of iron! No **** a cast iron block is going to weigh more than an alloy. You're simply genius. A DOHC inline 8 wouldn't be huge in height or width, it'd be very compact actually. But the length would go beyond a limit that most engine bays could handle. So they take the 8 slugs, put them in a V configuration, and double the width. But most engine bays can still handle this width, barely, with the pushrod engine. However in terms of width and height, the inline is much more compact.
Clearly, sport bike engines are too different from automobile engines for meaningful comparison in this regard.
But, bear in mind: this only works if you are comparing two engines of similar configuration, application, and output. Like say an LS1 vs an LS2 or LS7. But even then, what is the sense in it? All three of those weigh the same and are the exact same size, so why compare power per liter? Why should liter-specific output be meaningful rather than total output or output per weight or output per fuel consumption? I have yet to hear a reason for that apart from displacement-restricted racing or taxes.
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Originally Posted by LSGunZ28
I did read what you wrote. But Id take a harely over a sport bike, for the very reason that I want torque in all RPMs.
also you are comparing sportbokes with LSX engines. Its different, LSX engines go in sport cars, not bikes.
I dont doubt your knowledge, but Im just sayin'
also you are comparing sportbokes with LSX engines. Its different, LSX engines go in sport cars, not bikes.
I dont doubt your knowledge, but Im just sayin'
I'm not comparing sportbike engines to the LSX series, I'm simply pointing out a class where HP/L is very important. Because the manufacturer's keep such a high level of tune, and strive to keep displacements the same, that the power extracted from each unit displacement is crucial to that machine's ability to outperform the others.
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Originally Posted by black_knight
That's not what happened at all. Fact is, you're using ricer thinking: wanting HP/L for its own sake. There is no sense in this and so we called you on it.
If you don't think that it's ricer math, then answer one simple question: WHY? Why do you want horsepower PER LITER? Why not horsepower per engine size/weight/fuel consumption/$?
If you don't think that it's ricer math, then answer one simple question: WHY? Why do you want horsepower PER LITER? Why not horsepower per engine size/weight/fuel consumption/$?
While there is no doubt that fuel consumption, packaging, and weight all play pivotal roles in the use of one engine over another, there are some universal concepts that make one engine better than another. Just like the LSx engines are a vast improvement over the old flathead V8s, so too will the LS1 become "old" technology.
I think the combination of miami993c297 is the future of LSx engine development, at least in the aftermarket realm, but I would like to see this in production motors with MAF operating systems and great street manners. So, with that in mind, what innovations are needed for the future to get to the level of performance displayed by miami993c297 in a production vehicle?
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I think so many people get caught up in specific output they fail to see the real story. The LSx motors are so good at what they do because of there power density. Not many engines can contain 427 ci inside of an engine that weighs less and is smaller than a 281 ci DOHC Ford engine. Its the reason why a well maintained LSx motor can go to 150k or 200k miles because its relatively understressed for its power. There isn't a 505 hp car on the whole planet other than the C6 Z06 that comes with a 100k mile powertrain warranty. Now that says something about engineering an engine to have many contradicting goals.
1. Big Power Big Fuel economy
2. Big displacement small size
3. Cammy high rev power great low end torque
4. Long stroke High Rpm
This only gets better when they incorporate tricks like DI and VVT into the LS series.
1. Big Power Big Fuel economy
2. Big displacement small size
3. Cammy high rev power great low end torque
4. Long stroke High Rpm
This only gets better when they incorporate tricks like DI and VVT into the LS series.
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My argument against comparing any engine by HP/liter (or HP/CI) is that you are looking at a peak number at an instant in time that varies engine to engine. It has very little to do with a vehicles ability to accelerate unless you are sitting on that peak all of the time.
If you built an engine to optimize it's peak HP # you would most likely kill its ability to accelerate and hurt drivabilty.
If you built an engine to optimize it's peak HP # you would most likely kill its ability to accelerate and hurt drivabilty.
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Originally Posted by FieroZ34
You've obviously never ridden a sportbike. If you had read what I'd written, you'd see the part where the bike has low end. Almost too much for it's own good, as the CBR I rode could lift the tire, without any clutch input, in 1st or 2nd gear at any RPM. Not to mention there isn't a single point in the rpm range where the sportbike won't annihilate a Harley. From a 1500rpm roll, a GSX-R1000 would destroy any Harley made. It'd be like a Z06 lining up to a 13 liter 18-wheeler. Yah, the Z06 is down on displacement, power, and torque, but it still won't be a contest.
I'm not comparing sportbike engines to the LSX series, I'm simply pointing out a class where HP/L is very important. Because the manufacturer's keep such a high level of tune, and strive to keep displacements the same, that the power extracted from each unit displacement is crucial to that machine's ability to outperform the others.
I'm not comparing sportbike engines to the LSX series, I'm simply pointing out a class where HP/L is very important. Because the manufacturer's keep such a high level of tune, and strive to keep displacements the same, that the power extracted from each unit displacement is crucial to that machine's ability to outperform the others.
You still cant compare em though.
#53
You forget bike motors. Americans also can build small engines that produce. The 1200 h.p. 8 injector not running on pump gas 2.0 engine found in all GM mini pro stocks puts out h.p 1/4 mile at a times faster than 99% of the people posting here..
Reliable + h.p. try ever sprint car in America. Every from of motor sports in America.
NASCAR builds reliable push rod engines. The Japs are no match yet. Even filed, so many L's.
Those little Jap motors with all the H.P. is also horse p---.
GM build a 2.4 called an LD-9 engine. Who knows what it was in? Bad water pumps, bad oiling, a real junk engine. My experience was you could become a member of Club Si with a Chevrolet LD-9. You could offer to race any full interior, original factory engine, street tired auto or stick Honda. Could care less about h.p., within 500 miles of Dayton Ohio. You could do this for four years. Get removed from the web page 6 times. Facts are, one loss in 4 years. Driver error, got treeded.
H.P. is a great bragging point. HP will allow you to run more mph. There are hundreds of things other than h.p. to get a car from point a to b quicker. What is more important? So many h.p. per cuin, or something else? My vote goes for something else, but great topic.
Reliable + h.p. try ever sprint car in America. Every from of motor sports in America.
NASCAR builds reliable push rod engines. The Japs are no match yet. Even filed, so many L's.
Those little Jap motors with all the H.P. is also horse p---.
GM build a 2.4 called an LD-9 engine. Who knows what it was in? Bad water pumps, bad oiling, a real junk engine. My experience was you could become a member of Club Si with a Chevrolet LD-9. You could offer to race any full interior, original factory engine, street tired auto or stick Honda. Could care less about h.p., within 500 miles of Dayton Ohio. You could do this for four years. Get removed from the web page 6 times. Facts are, one loss in 4 years. Driver error, got treeded.
H.P. is a great bragging point. HP will allow you to run more mph. There are hundreds of things other than h.p. to get a car from point a to b quicker. What is more important? So many h.p. per cuin, or something else? My vote goes for something else, but great topic.
#54
Originally Posted by germeezy1
I think so many people get caught up in specific output they fail to see the real story. The LSx motors are so good at what they do because of there power density. Not many engines can contain 427 ci inside of an engine that weighs less and is smaller than a 281 ci DOHC Ford engine. Its the reason why a well maintained LSx motor can go to 150k or 200k miles because its relatively understressed for its power. There isn't a 505 hp car on the whole planet other than the C6 Z06 that comes with a 100k mile powertrain warranty. Now that says something about engineering an engine to have many contradicting goals.
1. Big Power Big Fuel economy
2. Big displacement small size
3. Cammy high rev power great low end torque
4. Long stroke High Rpm
This only gets better when they incorporate tricks like DI and VVT into the LS series.
1. Big Power Big Fuel economy
2. Big displacement small size
3. Cammy high rev power great low end torque
4. Long stroke High Rpm
This only gets better when they incorporate tricks like DI and VVT into the LS series.
Bingo. this one hit the nail on the head. you can scream and rant and rave about your 100 hp/L 4 cylinder all day long. i dont care that it can make the same amount of power that my v8 can make N/A. the bottom line is this: if you get 500 hp from a 2.4 liter turbocharged motor, and 500 hp from a naturally aspirated 5.7 liter motor, the only possible advantage for a street car would be IF that 2.4L motor weighed less and had a smaller dimension than the 5.7 Liter motor. the 2.4L motor will be more stressed, get worse gas milage, have worse manners at low rpms, and in general will be more costly in the end. and ya know what? with the advent of the ls1 you now have a production motor that is smaller and weighs less than a honda 3.0L v6 motor. the 3.0 is more efficient, per liter. it puts out 240-260 horse. the v8 is less efficient but creates more power, in a package that is smaller and lighter. fully dressed these things weigh around 430 pounds. last v6 we pulled from a new honda weighed damn near 500-550.
heres just an interesting little sidenote for ya. some locomotive details. these motors are not power per liter- but they pump out tremendous amounts of power and they run for well over a million miles. the engines actually run straight water in the cooling system, so anytime the temperature will be below 32 degrees the motors sit and idle continuously. even in warm weather, the engines are more likely to be kept idling continously between trips than shut down. at full throttle, a modern locomotive will produce 4400-4600 horsepower at right around 1000 rpm at load. there is a certain model that produces 6000 horsepower. these are 12 and 16 cylinder diesel motors with tanks that hold around 4-5000 gallons of fuel. modern locomotives dont even use the diesel motor to apply force to the track. instead they run generators and alternators of sorts, depending on what kind of current they are built to use, ac or dc. this current powers electric motors at each wheel. the current produced from this massive diesel motor runs up to 1000 volts. this system delivers "tractive effort," or force to the rails in the direction of travel in thousands upon thousands of pounds. think of 27,000 KLPs of pressure. this is enough to move something as heavy as say a coal train, which can tip the scales at around 16,000 tons, fully loaded. the engine alone weighs 200 ton, or about 415,000 pounds.
#55
how much of a role does # of cylinders/displacement really make? Does it change the necessary rpm to achieve hp? Ducati v-twins make nearly the same hp at lower rpm than i4's and are more streetable. On the otherhand, F1 cars distribute the displacement over more cylinders, wether it be 2.8l v-8 or 3.0l v-10, and make huge hp #s, and can rev past 20,000rpm(restricted to 19k), but are not very streetable or reliable for that matter.
On a different note, does anyone have anything to say about Wankle/rotary engines?
On a different note, does anyone have anything to say about Wankle/rotary engines?
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Originally Posted by gallardo259
how much of a role does # of cylinders/displacement really make? Does it change the necessary rpm to achieve hp? Ducati v-twins make nearly the same hp at lower rpm than i4's and are more streetable. On the otherhand, F1 cars distribute the displacement over more cylinders, wether it be 2.8l v-8 or 3.0l v-10, and make huge hp #s, and can rev past 20,000rpm(restricted to 19k), but are not very streetable or reliable for that matter.
I disagree that the Ducatti is more streetable. Having ridden both Ducattis and other 1000cc sportbikes, there is no difference in streetability. As I said before, the 4s have plenty of low end. And with the introduction of dual stage fuel injection, and precise tuning, the power delivering is strong, smooth, and without hiccups (Unlike the old days of carbs). And even in midrange power, the twin doesn't even have any advantages. They are pretty even up until about 8,000rpm, where the 4s start to really wake up.
Secondly, your numbers are flawed. The Ducatti does NOT make as much power as any of the competing I4 squids. From www.sportrider.com, the 20006 999s made 139whp @ 10,000rpm, whereas every I4 squid made right around 160whp @ 11,500-12,500 rpm. And that 20whp is a HUGE difference in these bikes.
Because F1 distributes the displacement over more cylinders, that is where they get their HUGE rpm numbers, and consequently power numbers from. Same as the bike theory, they have much lower internal weights, and they take the same headflow and give it to smaller cylinders, which means higher VE.
On a different note, does anyone have anything to say about Wankle/rotary engines?
Last edited by FieroZ34; 06-04-2007 at 09:32 PM.
#57
hey thanks for explaining it to me, and i like the rotary poster!! The Duc I was thinking of was an S4R (996 or 998 in 'Monster' form, naked chasis) that a friend of mine has that makes over 150hp, maybe it's not stock. So is it the ablility to put the power to the ground that the Ducati has, that makes it competitive in racing (WSB)?
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I've got a whole bunch of those. They're pretty funny, even if not completely true...hehe
Your friend's bike must be modified a bit, because the highest power Duc is the one I quoted, the 999s. The racing part for sportbikes I'm not too familiar with, however I'm sure they give advantages to the V-twins, like perhaps a lower weight limit or something to that affect, because especially in racing, the advantage of having a 4cyl would be tremendous. Putting the power to the ground is much different in bikes than in cars. You don't really have to worry about wheelspin, because tthe tire is wide, made of great compounds, and all the bike's weight transfers on it upon acceleration. Thus bikes are far more likely to pull the front wheel up, which is the equivalent to a car spinning (Looks cool, but doesn't make you go fast). But the rider can shift his weight onto the front to help keep the wheel down. Also, I believe the racing bikes have traction control nowadays...Correct me if I'm wrong on that.
Your friend's bike must be modified a bit, because the highest power Duc is the one I quoted, the 999s. The racing part for sportbikes I'm not too familiar with, however I'm sure they give advantages to the V-twins, like perhaps a lower weight limit or something to that affect, because especially in racing, the advantage of having a 4cyl would be tremendous. Putting the power to the ground is much different in bikes than in cars. You don't really have to worry about wheelspin, because tthe tire is wide, made of great compounds, and all the bike's weight transfers on it upon acceleration. Thus bikes are far more likely to pull the front wheel up, which is the equivalent to a car spinning (Looks cool, but doesn't make you go fast). But the rider can shift his weight onto the front to help keep the wheel down. Also, I believe the racing bikes have traction control nowadays...Correct me if I'm wrong on that.
#59
Originally Posted by FieroZ34
Believe it or not, a 1 liter engine is a bit smaller than an LS1. A little.
That's my point exactly. It isn't because they are bike engines at all, it's because they are an inline configuration.
So why do motorcycle companies sell pretty much identical bikes, but with different engine sizes? Because liters DO matter.
You're right, the M3 engine does weigh more than the LS1. That's because it's made out of iron!
Exactly. Their engines are tuned to such a high level, as are their competitors, that the HP/L extracted is very important.
An LS7 weighs more than the LS2, which weighs more than the LS1.
#60
Originally Posted by Quick Double Nickel
I guess I should have referred to the thread as "Horsepower per cubic inch displacement", and then maybe you'd understand what the question really was.