Found this stupid junk on Howstuffworks.com
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The Beer-man
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Found this stupid junk on Howstuffworks.com
Quoted from howstuffworks.com
"...the displacement tells you something about how much power an engine can produce. A cylinder that displaces half a liter can hold twice as much fuel/air mixture as a cylinder that displaces a quarter of a liter, and therefore you would expect about twice as much power from the larger cylinder. So a 2.0 liter engine is roughly half as powerful as a 4.0 liter engine."
Honda 2.4L 240hp
Ford 4.6L 300hp
Not quite half as powerful......maybe in a perfect world.
"...the displacement tells you something about how much power an engine can produce. A cylinder that displaces half a liter can hold twice as much fuel/air mixture as a cylinder that displaces a quarter of a liter, and therefore you would expect about twice as much power from the larger cylinder. So a 2.0 liter engine is roughly half as powerful as a 4.0 liter engine."
Honda 2.4L 240hp
Ford 4.6L 300hp
Not quite half as powerful......maybe in a perfect world.
It all depends how you think about it. The displacement really does provide the potential to produce more power. Althouth the "half as powerful" may be a bad statement to make. Imagine if Honda produced a 4 liter engine and put the same high tech engineering into it as a smaller 2 liter engine. Most likely the 4 liter would probably produce nearly twice as much power, but then you also get into a million different factors, like what is the engine designed for...etc. "How Stuff Works" is not meant to give you a detailed lesson in internal cumbustion engines, but they should at least mention that it really isn't as simple as they state.
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Originally Posted by acjones20
if all things equal, these statements are very true! Think of a turbo, twice the boost and fuel (on a built engine) will produce twice the HP.
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In fact heres some info for you
Stock S2000
at 6700 rpm the S2000 is putting down about 160 whp.
But still we are comparing at high output 4 cylinder to a fairly crude V8, soooo
To make this more fair, we could compare a crude 2 liter 4 cylinder to a crude 4 liter V8.
For that we could compare the 1993 Honda Prelude Si, 2.2 liter making 160 hp to the 2001 Mustang GT 4.6 liter making 260 hp, looks pretty close to me
You could compare the high output engines also, say the 2.0 240hp motor out of the S2000 to the 3.6 liter out of a Ferrari 360 Modena making 395 hp. If you extend the Ferraris displacement out to 4.0 liters it would be making about 440 hp. Again it seem pretty close to me.
Stock S2000
at 6700 rpm the S2000 is putting down about 160 whp.
But still we are comparing at high output 4 cylinder to a fairly crude V8, soooo
To make this more fair, we could compare a crude 2 liter 4 cylinder to a crude 4 liter V8.
For that we could compare the 1993 Honda Prelude Si, 2.2 liter making 160 hp to the 2001 Mustang GT 4.6 liter making 260 hp, looks pretty close to me
You could compare the high output engines also, say the 2.0 240hp motor out of the S2000 to the 3.6 liter out of a Ferrari 360 Modena making 395 hp. If you extend the Ferraris displacement out to 4.0 liters it would be making about 440 hp. Again it seem pretty close to me.
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Rep Power: 328 You guys are also forgetting something else: they are talking about same amounts of cylinders, whereas you are getting on their nuts using the reference of a 4cyl vr and 8cyl.
THeir theory works if you take a 2.0 liter 6cyl and a 4.0 liter 6cyl.
THeir theory works if you take a 2.0 liter 6cyl and a 4.0 liter 6cyl.
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Rep Power: 300 Also you forget other factors that increase hp like valve timing mechanisms, compression, ecu's, etc... They are saying that all things being equal, exactly equal, a 4 will have twice the power of a 2 liter. This means you can't really compare out of brand engines.
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acjones20, if you double your boost and fuel, you will not double hp. the more air and boost you cram in the engine , your volumetric efficiency decreases. me and some friends had this argument that if you had 14.7 lbs of boost, it would be double of atm pressure therefore a N/A car with 14.7 lbs of boost would be double hp, not to say that a civic with 14.7 lbs of boost wouldn't hit 254 hp, but the volumetric efficiency does change.
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Originally Posted by shady88
acjones20, if you double your boost and fuel, you will not double hp. the more air and boost you cram in the engine , your volumetric efficiency decreases. me and some friends had this argument that if you had 14.7 lbs of boost, it would be double of atm pressure therefore a N/A car with 14.7 lbs of boost would be double hp, not to say that a civic with 14.7 lbs of boost wouldn't hit 254 hp, but the volumetric efficiency does change.
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Originally Posted by ctx66
theres always exceptions. but "theres no replacement for displacement" is still the truth. i dont think that comment will get much love on a honda board though. 
and so does my crude but effective 5.9L v-8 
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Rep Power: 0 It's all about torque curves. It's not uncommon to spin a 4 cyl to higher rpm to make hp. That means the torque curve, which is primarily dictated by the cam, has been moved up the rpm range. The high spinning 4 cyl will have crap for low end torque, but make it's power by spinning the motor higher.
V8s don't need to spin the motor to make hp because they have more torque thanks to more displacement. Take a V8 and cam it to spin higher and you'll make even more hp, but at the loss of low end torque.
My 351C spins to a modest 6,800 rpm, but makes plenty of hp. Good enough for consistent low 12s in a '69 Mach 1. My 440 spins to the same rpm, but puts my '70 Challenger down the track in the 10s. More displacement = more torque in the same rpm range. I could build the 351C to run the same times, but it would have to spin in the high 7000s to do it.
All things being equal, it's cheaper and more reliable to have more displacement and spin the motor slower. The motor is less stressed.
V8s don't need to spin the motor to make hp because they have more torque thanks to more displacement. Take a V8 and cam it to spin higher and you'll make even more hp, but at the loss of low end torque.
My 351C spins to a modest 6,800 rpm, but makes plenty of hp. Good enough for consistent low 12s in a '69 Mach 1. My 440 spins to the same rpm, but puts my '70 Challenger down the track in the 10s. More displacement = more torque in the same rpm range. I could build the 351C to run the same times, but it would have to spin in the high 7000s to do it.
All things being equal, it's cheaper and more reliable to have more displacement and spin the motor slower. The motor is less stressed.
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Rep Power: 328 You guys just dont get it. The example is two virtually identical motors, from the same company, same number of cylinders, the only difference being one is 2 liter and one is 4 liter.
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The Beer-man
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Originally Posted by EManEX
Metallica454 Myth BUSTED!
Metallica454 myth? I found it on howstuffworks.com. It aint my work. There's the way it works in theory and the way it works in the real world.
I sure wish my car was newer
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Rep Power: 364 Some of you are also forgetting that Honda puts tons of money into getting all the hp out of their newer engines that they can. Ford and Chevy detune the f'ing **** out of their muscle cars for the average driver. They let Edelbrock and other companies make the engines work at their full potential. That's why an intake will give us 3whp and will give a Mustang 26whp.
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Rep Power: 0 you guys turned an easy and good comparison and made it too complicated. It's like saying if you had 1 16oz glasses you could hold twice as much water as 1 8oz glass. Then you guys are going on to argue, "Yea but what if my hand gets tired from holding the heavier glass" or "yea, but what if i only had 12oz of water to fill the glasses up."
GEESH, give it a rest. It's true. Do the math. 2.0L engine can hold X amount of air and X amount of gas. A 4.0L motor can hold 2X amount of air and 2X amount of gas. So, it can also produce 2X the amount of power. No whatiffs, no buts, no nothin. It's mathematically true.
GEESH, give it a rest. It's true. Do the math. 2.0L engine can hold X amount of air and X amount of gas. A 4.0L motor can hold 2X amount of air and 2X amount of gas. So, it can also produce 2X the amount of power. No whatiffs, no buts, no nothin. It's mathematically true.
