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  #61  
Old 06-30-2006, 04:26 PM
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But they aren't intelligent which is the point and a very relevent one when considering any "information" he attempts to supply. This has alot to do with this thread.
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  #62  
Old 06-30-2006, 06:01 PM
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Quote:
Originally Posted by KnifeEdge_2K1
but for the cars they're putting it in, space isn't an issue, expecially with american cars
That's not neccessairly true. The LS3 or 4 (I can't remember which) version of the Gen 4 is used in several FWD cars now, and small packing would be needed for that. If you check out engine bay shots, they're crammed pretty tight with engine. In older cars, yes they had huge cars with huge engine bays with plenty of space, but the OHC makes the engine very tall. This is one of the problems with the BA- V8 Falcons, especially the higher spec one like the GT. The engine is so tall and the weight so high that can have an adverse effect on handling.

Quote:
Originally Posted by KnifeEdge_2K1
with your reasoning it should be the americans adopting dohcs and the europeans sticking with the older pushrods

so the small package excuse isnt valid at all, which leads back to the original question, why dont they change ??
Because they don't see a reason to. Pushrod gives them more than adequate results for their purposes, so why change? Same goes for Euro manufacturers.
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  #63  
Old 06-30-2006, 07:48 PM
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Originally Posted by h00t_h00t
But they aren't intelligent which is the point and a very relevent one when considering any "information" he attempts to supply. This has alot to do with this thread.
Using a blanket statement like “Everything you write is wrong” doesn’t provide anything valuable to the forum. If you feel that the information he has supplied is incorrect then you should provide the correct information.
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  #64  
Old 06-30-2006, 09:26 PM
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Quote:
Originally Posted by 2ndclasscitizen
That's not neccessairly true. The LS3 or 4 (I can't remember which) version of the Gen 4 is used in several FWD cars now, and small packing would be needed for that. If you check out engine bay shots, they're crammed pretty tight with engine. In older cars, yes they had huge cars with huge engine bays with plenty of space, but the OHC makes the engine very tall. This is one of the problems with the BA- V8 Falcons, especially the higher spec one like the GT. The engine is so tall and the weight so high that can have an adverse effect on handling.


Because they don't see a reason to. Pushrod gives them more than adequate results for their purposes, so why change? Same goes for Euro manufacturers.
i'm not gonna say all but in most cases the payoff from switching to ohc is greater then the effect on handling, the COG on the car moves only by a small amount and minor suspension adjustments can easily compensate

i'm not saying that pushrods dont have their place, but i'm saying that for 99% of the time nowadays, ohc is the way to go, and why american engines are still so far behind is beyond me
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  #65  
Old 06-30-2006, 09:30 PM
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i agree with you one one thing, the pushrods does provide adequate results for their purpose, which is profit, the engines are so old in design they're prolly much cheaper to make then a euro equivilant. i understand it's a corporation job to increase profits, but those profits should be reinvested into product design and R&D to make a better product, i just dont see that happening in american car companies
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  #66  
Old 07-01-2006, 02:54 AM
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Quote:
Originally Posted by KnifeEdge_2K1
so if you make the same horsepower with more displacement which naturally means more fuel, how is this efficient ??
the engines displacement has little to do with how much fuel is used. The total output is the main factor. If you have a 2L I4 that makes 200hp and a 4L V8 that makes 200hp then they use roughly the same amount of fuel (in real life the smaller engine would use more because it probably runs richer to control knocking)

Quote:
Originally Posted by KnifeEdge_2K1
if you increased the displacement of an engine which has vvt and lift, ohcs, direct injection, 4 valves per cylinder, etc
the benefits from those systems remain
I am not quite sure what you mean as VVTL, DOHC, DI, and 4valves per cyl. can have many varied benefits. Higher efficiency is possible through use of those systems and if that is what you mean than increasing displacement will increase total output and if the systems are redesigned to fit the bigger engine then yes their benefit to efficiency will remain.


Quote:
Originally Posted by KnifeEdge_2K1
you can only increase displacement so much before it becomes unfeasible, and at that point you'd rather have vvt and lift, ohcs, direct injection, 4valves per cylinder, then not
Well a 9L V10 seems feasible in the american market and you don't need any more power than that can give you. However in small cars that you want to give power to you are totally correct. I don't mean that using displacement to increase total output is the right thing to do, I am just trying to explain why americans do it and why it isn't a dumb thing to do.

Quote:
Originally Posted by KnifeEdge_2K1
assume i'm wrong about this efficiency thing, what in your definition is efficiency then ? mpg ? emmissions ? thermal efficiency ? volumetric efficiency ? what then
in most if not all of these areas american tuned engines fail to compare with euro or jap standards
This is a stereotype that is not true. First you where not wrong you where just using the wrong words (you said efficiency when you meant specific power) An engines efficiency for me is the amount of the theritical total energy available from the fuel that is transferred to motive force, (thermal efficiency) A very good measure of this is the Brake Specific Fuel Consumption (rated in lbs/hp/hr.) This number allows you to compare the efficiencies of any engine against any other as all the factors are taken into account. However there are a host of other efficiencies that you can discuss when talking about engines (volumetric efficiency, combustion efficiency, phase/pulse utilization efficiency, process[expansion and compression] efficiency, ect.) But you where not talking about any of those you where talking about HP/L which is a measure of specific output.

Now to address your stereotype. You said that american engines fail when it comes to efficiency but you are wrong. The LS7 is capable of a better BSFC rating than the Honda S2000's F22 engine however it will use more gas (it produces more than twice the power).

Hoot-Hoot: What is wrong? please if you do not agree with something I have posted tell me what ok? If not then keep your mouth shut about my posts.
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  #67  
Old 07-01-2006, 11:03 PM
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thermal efficiency is closely related to specific output tho, since a larger displacement engine tends to suck up more air, and thus more fuel, if they you double the displacement and keep everything else equal, you should double the power and thus keep specific output, obviously this is not a real world example as doulbing the displacement can have different effects depending on how it was done, but i think you see my point

anyways, this is just a disagreement on our opinions of what efficiency is, i still htink increasing displacement to increase output isnt the best way of doing it, i agree it will be an inevitible step when trying to obtain maximum power, given a 2 litre engine vs a 4 litre engine to work with all things equal the 4 litre will output more, but considering the added benefits of ohc and vvt and what not, it seems to me at least that just making bigger engines is an inefficient use of resources
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  #68  
Old 07-02-2006, 03:43 AM
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Quote:
Originally Posted by KnifeEdge_2K1
thermal efficiency is closely related to specific output tho, since a larger displacement engine tends to suck up more air, and thus more fuel, if they you double the displacement and keep everything else equal, you should double the power and thus keep specific output, obviously this is not a real world example as doulbing the displacement can have different effects depending on how it was done, but i think you see my point
Hmm I think you are missing something if you make an engine bigger it should produce more torque per revolution (due to the increase in air and fuel consumed) however peak HP relies on a high redline and normally the bigger the engine the lower the redline. So making an engine twice as big should only increase power by 2 if the redlines are the same This is another reason why americans like having big engines because it means you don't have to rev them as much to get the same power. However Thermal efficiency is not related to specific output (as I have shown with the huge diesel example [it can surpass 50% thermal efficiency but only makes 4.27hp/L] thermal efficiency and specific output are not related)

Quote:
Originally Posted by KnifeEdge_2K1
anyways, this is just a disagreement on our opinions of what efficiency is, i still htink increasing displacement to increase output isnt the best way of doing it, i agree it will be an inevitible step when trying to obtain maximum power, given a 2 litre engine vs a 4 litre engine to work with all things equal the 4 litre will output more, but considering the added benefits of ohc and vvt and what not, it seems to me at least that just making bigger engines is an inefficient use of resources
You are absolutely right I wonder when americans will finally put there substansal resources into making better use of the many engine advancements available today. They are started already but they seem to have a steep learning curve.
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Last edited by hightower99; 07-02-2006 at 03:49 AM.
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  #69  
Old 07-02-2006, 08:45 AM
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Quote:
Originally Posted by hightower99
Hmm I think you are missing something if you make an engine bigger it should produce more torque per revolution (due to the increase in air and fuel consumed) however peak HP relies on a high redline and normally the bigger the engine the lower the redline. So making an engine twice as big should only increase power by 2 if the redlines are the same This is another reason why americans like having big engines because it means you don't have to rev them as much to get the same power. However Thermal efficiency is not related to specific output (as I have shown with the huge diesel example [it can surpass 50% thermal efficiency but only makes 4.27hp/L] thermal efficiency and specific output are not related)


You are absolutely right I wonder when americans will finally put there substansal resources into making better use of the many engine advancements available today. They are started already but they seem to have a steep learning curve.
what ?? dude, horsepower is a measure of work per time, gasoline has a specific amount of energy per unit, if you consume more gas then you should get more power at equal conditions, that's why i'm saying it's closely related to thermal efficiency, if everything was held equal then doubling displacment wont affect specific output, but your argument is american engines increase displacement to increase power as opposed to technology (which naturally means higher thermal efficiency but ill leave that for another time), and since american engines have lower specific output compared to euro engines which have similar redlines and peak power rpm figures, i'm making the conclusion that american engines are inefficient

if you see a flaw in this let me know

the reason ur example doesnt work is because it operates in low rpms, almost all car engines operate in the same range between 5-7k rpm for the engines we're looking at, and thus this factor is more or less irrelevant
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  #70  
Old 07-05-2006, 04:05 AM
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Quote:
Originally Posted by KnifeEdge_2K1
what ?? dude, horsepower is a measure of work per time, gasoline has a specific amount of energy per unit, if you consume more gas then you should get more power at equal conditions
Yes you should gain more power when more fuel is used and you do.

Quote:
Originally Posted by KnifeEdge_2K1
that's why i'm saying it's closely related to thermal efficiency
You lost me here. You said that specific power (HP/L) is related to thermal efficiency but it is not, thermal efficiency doesn't come into the matter when talking about HP/L.

Quote:
Originally Posted by KnifeEdge_2K1
if everything was held equal then doubling displacment wont affect specific output
No it wouldn't if you kept all else equal, however americans make bigger engines so that they don't have to maintain the HP/L rating to achieve good total output.

Quote:
Originally Posted by KnifeEdge_2K1
but your argument is american engines increase displacement to increase power as opposed to technology (which naturally means higher thermal efficiency but ill leave that for another time)
Wrong increasing engine size increases total output because more fuel is used. But that does not mean that they have to be more thermally efficient, although in most cases they don't do too bad.

Quote:
Originally Posted by KnifeEdge_2K1
and since american engines have lower specific output compared to euro engines which have similar redlines and peak power rpm figures, i'm making the conclusion that american engines are inefficient
OK this doesn't make much sense and I will give you an example to explain: Engine A is a 4L V8 that produces 400hp@8000rpm

Engine B is a 6L V8 that produces 400hp@7000rpm.

Now engine A makes 100HP/L but engine B only makes 66.7HP/L, I believe you would look at only those numbers and say that engine B was less efficient.

Now let me tell you that Engine A has a volumetric efficiency of 120% (granted by DOHC amd 4 valves per cylinder as well as a supercharger)

Engine B has 80% (single "in block" cam working on pushrods on OHV with 2 valves per cylinder)

so both "breath" 4.8L of air, however engine A requires a 13:1 air:fuel ratio to help cool it and to control knock, Engine B runs with a 15:1 ratio which means that (if they are perfect engines that lose nothing to friction) then Engine A is 41.1% thermally efficienct and engine B is a whopping 54.7% efficient. Now it may not be the fuel ratio all the time but building bigger engines allows you to make the same total power without working as hard.

Quote:
Originally Posted by KnifeEdge_2K1
the reason ur example doesnt work is because it operates in low rpms, almost all car engines operate in the same range between 5-7k rpm for the engines we're looking at, and thus this factor is more or less irrelevant
Wrong if you say that the HP/L rating of the deisel is irrelavant then you can't use it for anything other than comparing engine which experiance peak HP at almost the exact same rpm (max 500rpm difference) However the measure of efficiency I mentioned (lbs/hp/hr) allows you to compare any engines...

see my point?

HP/L has nothing to do with efficiency and it is not a smart or valueable measurement when trying to compare engines.
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  #71  
Old 07-05-2006, 10:41 AM
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Quote:
Originally Posted by hightower99
Yes you should gain more power when more fuel is used and you do..
but the percentage % in power is not the same as % inrease in fuel consumed, doubling displacement means that at the same rpm a 4L engine would consume twice the amount of air as a 2L engine and thus twice the amount of fuel, given all other conditions are equal, burning twice the amount of fuel under equal thermal efficiency conditions would yield twice teh amount of power and thus keep specific output the same, dude this is as simple as i can put it, if you still dont understand then you shouldn't call urself an engineer


Quote:
Originally Posted by hightower99
You lost me here. You said that specific power (HP/L) is related to thermal efficiency but it is not, thermal efficiency doesn't come into the matter when talking about HP/L..
read above paragraph

Quote:
Originally Posted by hightower99
No it wouldn't if you kept all else equal, however americans make bigger engines so that they don't have to maintain the HP/L rating to achieve good total output..
i never said their output was bad, i said their output when you look at what they input to get it, it's like investments, two investments which yield $100
a year arnt the same if one costs $1 and the other $100, one is just 2x the yield while the other is 100x

Quote:
Originally Posted by hightower99
Wrong increasing engine size increases total output because more fuel is used. But that does not mean that they have to be more thermally efficient, although in most cases they don't do too bad..
i was refering to how technology naturally increases thermal efficiency, and volumetric efficiency, and etc.


Quote:
Originally Posted by hightower99
OK this doesn't make much sense and I will give you an example to explain: Engine A is a 4L V8 that produces 400hp@8000rpm

Engine B is a 6L V8 that produces 400hp@7000rpm.

Now engine A makes 100HP/L but engine B only makes 66.7HP/L, I believe you would look at only those numbers and say that engine B was less efficient.

Now let me tell you that Engine A has a volumetric efficiency of 120% (granted by DOHC amd 4 valves per cylinder as well as a supercharger)

Engine B has 80% (single "in block" cam working on pushrods on OHV with 2 valves per cylinder)

so both "breath" 4.8L of air, however engine A requires a 13:1 air:fuel ratio to help cool it and to control knock, Engine B runs with a 15:1 ratio which means that (if they are perfect engines that lose nothing to friction) then Engine A is 41.1% thermally efficienct and engine B is a whopping 54.7% efficient. Now it may not be the fuel ratio all the time but building bigger engines allows you to make the same total power without working as hard.
.
you're just making up numbers here so it's not really valid as an example, mine kept everything equal which is what you do when you're trying to measure changes caused by one variable on another even tho there are many other deciding factors in the equation. this is how science, engineering, economics, how the entire world works

Quote:
Originally Posted by hightower99
Wrong if you say that the HP/L rating of the deisel is irrelavant then you can't use it for anything other than comparing engine which experiance peak HP at almost the exact same rpm (max 500rpm difference) However the measure of efficiency I mentioned (lbs/hp/hr) allows you to compare any engines...

see my point?

HP/L has nothing to do with efficiency and it is not a smart or valueable measurement when trying to compare engines.
that's what i said, most cars opperate with max power figures within 500pm of the average which is somewhere in the 5-6k range
and you cant compare diesal and gas engines this way anyways since they're two different forms of fuel with different properties and applications
the lbs/hp/hr measure still only allows you to compare engines using the same type of fuel, and it still only allows you to compare two engines at a specific rpm, same limitation as hp/l

and next time, instead of just saying i'm wrong, say why i'm wrong and give valid examples instead of something you pull outta ur ass
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  #72  
Old 07-09-2006, 02:33 AM
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Quote:
Originally Posted by KnifeEdge_2K1
but the percentage % in power is not the same as % inrease in fuel consumed, doubling displacement means that at the same rpm a 4L engine would consume twice the amount of air as a 2L engine and thus twice the amount of fuel, given all other conditions are equal, burning twice the amount of fuel under equal thermal efficiency conditions would yield twice teh amount of power and thus keep specific output the same, dude this is as simple as i can put it, if you still dont understand then you shouldn't call urself an engineer
I understand that more fuel equals more power and that if everything else is equal burning twice the amount of fuel in an engine twice as big will maintain specific output, but that doesn't mean that specific output is related to the thermal efficiency of an engine. a 4L engine does not process twice as much air as a 2L engine and it doesn't need to. If it only processes 1.5 times as much air and uses 1.5 times as much fuel the output will be raised nicely, efficiency is kept the same but specific output drops. Do you see my point now?


Quote:
Originally Posted by KnifeEdge_2K1
i never said their output was bad, i said their output when you look at what they input to get it, it's like investments, two investments which yield $100
a year arnt the same if one costs $1 and the other $100, one is just 2x the yield while the other is 100x
I know what you are saying. But you seem to have misunderstood what I said. I said that american engines are big with low specific output because that is easier and cheaper to make than a smaller higher specific output engine. Just becuase american engines are big and low specific power does not mean they are inefficient, I have tried to explain this.


Quote:
Originally Posted by KnifeEdge_2K1
you're just making up numbers here so it's not really valid as an example, mine kept everything equal which is what you do when you're trying to measure changes caused by one variable on another even tho there are many other deciding factors in the equation. this is how science, engineering, economics, how the entire world works
First you only changed one thing once to make your example, to prove something it needs to be true for a number of examples and I have shown that it isn't and No I wasn't just making up numbers I figured two starting points (the stats of engine A & B) so that they are comparable and would be a valid comparison. The specific outputs I stated are true and I decided to show my point by having each engine have a different air:fuel ratio and I gave a decent reason as to why they would differ I also made sure that they processed the same amount of air to make my point clearer. The efficiency values I arrived at used the values of 1.29kg/m3 as air's density and 737.22kg/m3 as the density of petrol (gas) I converted the numbers to lbs/L using the conversion values of 2.2lbs=1kg and 1000L=1m3 No friction was taken into account. So my example is a very valid comparison and proves my point that HP/L has little to do with thermal efficiency.


Quote:
Originally Posted by KnifeEdge_2K1
that's what i said, most cars opperate with max power figures within 500pm of the average which is somewhere in the 5-6k range
and you cant compare diesal and gas engines this way anyways since they're two different forms of fuel with different properties and applications
the lbs/hp/hr measure still only allows you to compare engines using the same type of fuel, and it still only allows you to compare two engines at a specific rpm, same limitation as hp/l
Hmm you can compare diesel and gas engines, easily in fact. As long as engines are internal combustion you can compare them. lbs/hp/hr allows you to compare any engines, if you compare the average gas burning car engine against a super efficient diesel the values show that the diesel is the most efficient. Also about RPMs every engine that runs over a range of rpms will have different BSFC ratings at each rpm, however every engine has a maximum and minimum BSFC rating and an accurate average can be found easily removing the rpm restriction, which isn't even a restriction if you are comparing peak efficiency. HP/L is only a specific out rating it tells you absolutely nothing else why can't you understand that?

Quote:
Originally Posted by KnifeEdge_2K1
and next time, instead of just saying i'm wrong, say why i'm wrong and give valid examples instead of something you pull outta ur ass
I have been doing that most of the time and my examples are totally valid you just seem to not want to even pay them any attention.
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  #73  
Old 07-09-2006, 11:06 AM
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Quote:
Originally Posted by hightower99
I understand that more fuel equals more power and that if everything else is equal burning twice the amount of fuel in an engine twice as big will maintain specific output, but that doesn't mean that specific output is related to the thermal efficiency of an engine. a 4L engine does not process twice as much air as a 2L engine and it doesn't need to. If it only processes 1.5 times as much air and uses 1.5 times as much fuel the output will be raised nicely, efficiency is kept the same but specific output drops. Do you see my point now?


I know what you are saying. But you seem to have misunderstood what I said. I said that american engines are big with low specific output because that is easier and cheaper to make than a smaller higher specific output engine. Just becuase american engines are big and low specific power does not mean they are inefficient, I have tried to explain this.


First you only changed one thing once to make your example, to prove something it needs to be true for a number of examples and I have shown that it isn't and No I wasn't just making up numbers I figured two starting points (the stats of engine A & B) so that they are comparable and would be a valid comparison. The specific outputs I stated are true and I decided to show my point by having each engine have a different air:fuel ratio and I gave a decent reason as to why they would differ I also made sure that they processed the same amount of air to make my point clearer. The efficiency values I arrived at used the values of 1.29kg/m3 as air's density and 737.22kg/m3 as the density of petrol (gas) I converted the numbers to lbs/L using the conversion values of 2.2lbs=1kg and 1000L=1m3 No friction was taken into account. So my example is a very valid comparison and proves my point that HP/L has little to do with thermal efficiency.


Hmm you can compare diesel and gas engines, easily in fact. As long as engines are internal combustion you can compare them. lbs/hp/hr allows you to compare any engines, if you compare the average gas burning car engine against a super efficient diesel the values show that the diesel is the most efficient. Also about RPMs every engine that runs over a range of rpms will have different BSFC ratings at each rpm, however every engine has a maximum and minimum BSFC rating and an accurate average can be found easily removing the rpm restriction, which isn't even a restriction if you are comparing peak efficiency. HP/L is only a specific out rating it tells you absolutely nothing else why can't you understand that?

I have been doing that most of the time and my examples are totally valid you just seem to not want to even pay them any attention.
if it only processes 1.5x the amount of air then it becomes volumetrically inefficient leading to more pumping losses and thus less efficient, an engine's job is to pump as much air possible as quickly as possible, a 4L engine has the capacity to pump twice as much air in the same amount of time as a 2L engine, if it only pumps 3L of air then there is potential not being tapped, that to me is inefficient

and i have explained to you 3 times why a low specific output engine is inefficient compared to a high specific output engine of similar design

that's how scientific measures and study's are done, you change one variable to see it's effect on a target variable, even when there are other factors in the equation, my point is, bigger displacement shouldn't affect specific output if all other variables are held constant

your example was a specific example and doesnt hold true for all cases, mine is general and DOES apply to all cases with my stated restrictions, all you proved was that your engine A is less efficient then engine B, and would only hold true for engines with the same stats as A and B, you cant do inductive reasoning in this case

if you ever tried to use any of your examples in a thesis you'd fail for sure, you cant use inductive reasoning like this cuz it simply doesnt work, it's like saying my car has 4 wheels, therefore all cars have 4 wheels, it doesnt make sense, why can you compare any two internal combustion engines even though they're using different fuels ??

and back to the original argument, which was the efficiency of american engines vs euro or japanese engines, can you provide any examples of american engines being more efficient then euro engines ??
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  #74  
Old 07-10-2006, 07:51 AM
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http://www.chevyhiperformance.com/te...s/0508ch_carb/
Here is a link to a large american engine (A pushrod 5.7L LS1 with a carburetor! tuned to 519hp giving it 91HP/L) that shows a number of BSFC ratings where the lowest is listed as 0.382lbs/hp/hr.

And in this interesting paper: http://www.itepsa.com/samples/SIET199907_CH1_MAIN.PDF
it says that the best the Honda F20C can do is 378g/kWh so knowing that 1g/kWh = 0.00164398681lbs/hp/hr then the F20C is only good for 0.621lbs/hp/hr or roughly 63% more fuel used. And that is on a little 2L DOHC engine with high tech materials and a massive 120HP/L rating. Do you believe me now?

Oh and you can compare diesel and gas burning engines with only the BSFC number because diesel fuel weighs more than does gasoline per volume but its energy density is approximately the same. That makes it possible to compare the relative efficiencies of gasoline vs. diesel engines simply by comparing their BSFC numbers.

[QUOTE name=KnifeEdge_2K1]if it only processes 1.5x the amount of air then it becomes volumetrically inefficient leading to more pumping losses and thus less efficient, an engine's job is to pump as much air possible as quickly as possible, a 4L engine has the capacity to pump twice as much air in the same amount of time as a 2L engine, if it only pumps 3L of air then there is potential not being tapped, that to me is inefficient[/QUOTE]

Yes the volumetric efficiency is lower but that doesn't always mean that it has to work harder. You forget that if the engine is only moving 3L of air than that takes less energy than if it needed to move 4L of air. Most stock car engines are lucky if they reach 80% volumetric efficiency even though most engines are capable of over 150% with FI.

[QUOTE name=KnifeEdge_2K1]and i have explained to you 3 times why a low specific output engine is inefficient compared to a high specific output engine of similar design[/QUOTE] Funny I thought you where trying to show that lower tech american engines where less efficient than their high tech (not so similar) brothers. Also your explainations don't hold water and simply are not true and I think that you will see that by the end of this post.

[QUOTE name=KnifeEdge_2K1]your example was a specific example and doesnt hold true for all cases, mine is general and DOES apply to all cases with my stated restrictions, all you proved was that your engine A is less efficient then engine B, and would only hold true for engines with the same stats as A and B, you cant do inductive reasoning in this case[/QUOTE]
You missed the point of my example. You keep saying that your statement that engines with higher HP/L ratings are always more efficient than engines with lower HP/L ratings is general and is always true but I showed through a single valid example that this is not the case. I have now posted further valid proof that even though an engine has a higher HP/L rating it is not the most efficient (and in most cases is actually most likely to be the least efficient in a comparison). I have tried to tell you about the many other reasons why looking at the specific output measurement of HP/L will not tell you anything about efficiency but you don't seem to care?

So now you know: HP/L has nothing to do with efficiency OK!
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Engine torque is an illusion.
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