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Old 05-11-2019, 09:09 AM   #1
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How to know how efficient an engine is?

I was told that, given two engines, the engine that had the smallest gap between maximum torque rpm and maximum hp rpm is the one that is most efficient. Is this true?
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Old 05-11-2019, 09:40 AM   #2
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There is no correlation between those things and efficiency.

Horsepower is just a mathematical representation of torque over time. Torque is a real thing, it's a measurement of twisting force. Take that twisting force, multiply it by the speed at which you're delivering it (RPM), and divide by a mathematical constant of 5252 (a unit describing the amount of work a good horse can do) and you have your horsepower figure.

Being efficient is about wasting as little of the potential power of your fuel as possible. Somewhere north of 70% of the potential energy of your fuel is not turned into usable power at your rear wheels.
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Old 05-11-2019, 10:19 AM   #3
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There is no correlation between those things and efficiency.

Horsepower is just a mathematical representation of torque over time. Torque is a real thing, it's a measurement of twisting force. Take that twisting force, multiply it by the speed at which you're delivering it (RPM), and divide by a mathematical constant of 5252 (a unit describing the amount of work a good horse can do) and you have your horsepower figure.

Being efficient is about wasting as little of the potential power of your fuel as possible. Somewhere north of 70% of the potential energy of your fuel is not turned into usable power at your rear wheels.
So about 70% of the potential energy is converted into heat and friction? Wow! Quite a lot.
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Old 05-11-2019, 10:21 AM   #4
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Old 05-11-2019, 10:54 AM   #5
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what is efficient

Most of the energy from the fuel burned is going to go to the radiator. Some will be heat out the tail pipe. some will go to the crankshaft. This is a simplification, but catches what I think are the three main places, energy from the fuel goes to these places.

You can recover some energy from the exhaust by using a turbocharger. Now generally speaking, are more efficient when the air coming into the engine is as cool as you can get it. So , if you turbocharg, that heats the intake air, so you can cool it after it comes out of the turbocharger. Many different ways you can do this, but the most common is to use a kind of radiator called an "intercooler" or in the trucking world "aftercooler" cummins 6B is a 5.9 six cylinder diesel engine, 6BT is a cummins 5.9 with a T turbo charger, 6BTA is 5.9 with turbo and A aftercooler. Now you can even add water spray, like the one on your windshield washers and spray water on the intercooler when adding heat from heavy work, like, say, when you are going up a big hill. Air intake temperatures start going up, you turn on the sprayer to help keep the air cooler. You an enhance the effect by adding alcohol to the water.
any way here is the basic idea behind cool air in and hot out. take a balloon and blow it up about half way, and tie it off. put it in the freezer for half an hour. now take out the balloon and see the size. now turn on the oven to about 160 degrees and place the balloon on a sheet of paper and put that into the oven... take it out about 10 minutes later... See how much bigger the balloon is? Not counting any fuel at all. If you can get the air to expand inside the engine, cold air in, expands while in the cylinder, doing work pushing down on the piston, that by itself makes some power out put.

you can add a drop of water to the old air going in, and that drop, turned into vapor adds even more pressure inside that hot cylinder, even more work comes out and still we have not added any fuel.

So you have the cool in, hot out thing going on.

So if I can run the engine at 210 degrees all the time vs 190 degrees all the time, I will get a little better efficiency. The added benefit to hotter? is the water vapor in the engine oil will be driven out of the oil easier and faster. Means longer change intervals and the hotter oil will have less drag on internal parts along with other benefits. Cars and trucks in the 1960's often had 180 degree thermostats, now a new car often has 192 to 195 degree thermostats. the hotter engine can be made more efficient.

engine oil thickness, most efficient is thinner, but get it too thin and you will not protect your engine. synthetics are good here. In a diesel engine, a 10w40 at 20 degrees fahrenheit I would not be shocked if it took 30 to 60 seconds of run time for engine oil to make it to valve train on my cummins. at 100 degrees fahrenheit 15 seconds. thinner oil takes in and give up heat faster than a thicker oil. the pistons in our diesels are cooled with engine oil. Well most pistons are.

Injector timing - this is set in one place on my mehanical engine and has significant influence on fuel efficiency. The "e" electronic controlled injectors are not pinned down by this fixed parameter and is, in part, why they can make more power. You can also kill an engine within seconds if you change this and get it "wrong".

that is enough of this for now....

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Old 05-11-2019, 11:20 AM   #6
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In a gasoline motor, due to the fuel only burning when vaporized and mixed at a very narrow ratio with oxygen (air), a lot of waste is produced when the fuel doesn't even burn. It just goes out the exhaust pipe. Catalytic converters are added to finish burning the fuel, so it doesn't kill us and the planet as fast.


mixing in hydrogen, at the rate of roughly 5% of the BTUs of gasoline will make all the fuel burn in the cylinder and increase you efficiency greatly.


[[example with imaginary BTU values:
BTU of gasoline per cylinder cycle: 100
BTU of hydrogen per cylinder cycle: 5
]]


The fuel burns cooler also (unlike nitrous oxide enrichment) and protects your valves and motor that way.


The tech is simple, easy to deal with as propane (using new-fangled carbon fiber 10,00psi tanks), far safer than gasoline in a crash, and has been well developed since the 1960s. "THEY" don't want us to have industrial access to hydrogen, because that opens the door to using ANY fuel in your motor (diesel fuel or even veggie oil in a spark-motor gas burner!) and then they can't control the world and all the MONEY in it (why all oil is sold using US dollars, and why the US wants to oust Maduro, but ignores other "dictators")
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Old 05-11-2019, 11:24 AM   #7
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I have read that giant warehouses in Canada use hydrogen-enriched diesel forklifts inside all day long without air-pollution problems. All the fuel is burned completely in the motor. Water vapor and a bit of nitrous oxides is the only exhaust.
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Old 05-11-2019, 01:24 PM   #8
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there is a story in the area i live in about an engineer in the early 70s that made a workable engine that ran off of water and the GOVT bought him out to never produce it?
didnt live here then but have heard it many times.
interesting?
gotta research that?
thanks for the idea.
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Old 05-11-2019, 06:45 PM   #9
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Quote:
Originally Posted by Jolly Roger bus 223 View Post
there is a story in the area i live in about an engineer in the early 70s that made a workable engine that ran off of water and the GOVT bought him out to never produce it?
didnt live here then but have heard it many times.
interesting?
gotta research that?
thanks for the idea.
Water is not a source of energy: it is a highly stable molecule. It is a source of hydrogen, but it takes an input of energy to break the O-H-H molecular bond. you will never get as much energy out of burning the resulting free hydrogen as it takes to break that bond, so you will loose energy in the long run.
Electricity is used to break the hydrogen. If you could carry that much electrical charge on your vehicle, it is much simpler and more efficient and (as Tesla's 0-60 in about 2 seconds cars reveal) you get performance when you use an electric motor. So many more advantages.
Some say you could produce the electricity with your alternator, split water, and hyboost your gasoline motor, but the math does not work. You need an industrial supply of hydrogen produced with another fuel (fuel contains energy that freely releases for use): be it NG, LP, solar, hydroelectric dams, whatever. Hydrogen is just a wonderful universal carrier of the energy you can produce/release elsewhere. If it were found here on Earth in a free state (not molecularly bound to another atom), we could call it a source of fuel.
Hydrogen is a catalyst when burned with other fuels. This is called hyboosting.

Hydrogen boosting gasoline or diesel vehicles could "virtuously" instantly solve pollution problems. No new industry to replace. The same motors can still be used and continue to be made. The same old mechanics need not learn a whole new system (who here has repaired an electric vehicle's motor?) Someone designed hydrogen injectors that replace the spark plugs in gasoline motors (and porvide the spark also) so converting your 2017 Honda is as simple as converting your 1957 Chevy. They screw right in the motor. Modern diesels are trickier to get to work with hydrogen, due to its low flash temp. TBI systems can get backfires; running the stainless steel tubing that supplies the hydrogen down through the intake manifold to near the valves can help. And I know about nothing about using hydrogen with modern diesels with high-pressure injectors, etc, but if you could just hyboost those motors, you could ditch the DEF and get cleaner emissions. A properly configured hyboost engine actually cleans the air it breathes in (even the pollen for you allergy sufferers), especially in LA.
Sigh.....
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Old 05-11-2019, 07:01 PM   #10
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Quote:
Originally Posted by Mountain Gnome View Post
Water is not a source of energy: it is a highly stable molecule. It is a source of hydrogen, but it takes an input of energy to break the O-H-H molecular bond. you will never get as much energy out of burning the resulting free hydrogen as it takes to break that bond, so you will loose energy in the long run.
Electricity is used to break the hydrogen. If you could carry that much electrical charge on your vehicle, it is much simpler and more efficient and (as Tesla's 0-60 in about 2 seconds cars reveal) you get performance when you use an electric motor. So many more advantages.
Some say you could produce the electricity with your alternator, split water, and hyboost your gasoline motor, but the math does not work. You need an industrial supply of hydrogen produced with another fuel (fuel contains energy that freely releases for use): be it NG, LP, solar, hydroelectric dams, whatever. Hydrogen is just a wonderful universal carrier of the energy you can produce/release elsewhere. If it were found here on Earth in a free state (not molecularly bound to another atom), we could call it a source of fuel.
Hydrogen is a catalyst when burned with other fuels. This is called hyboosting.

Hydrogen boosting gasoline or diesel vehicles could "virtuously" instantly solve pollution problems. No new industry to replace. The same motors can still be used and continue to be made. The same old mechanics need not learn a whole new system (who here has repaired an electric vehicle's motor?) Someone designed hydrogen injectors that replace the spark plugs in gasoline motors (and porvide the spark also) so converting your 2017 Honda is as simple as converting your 1957 Chevy. They screw right in the motor. Modern diesels are trickier to get to work with hydrogen, due to its low flash temp. TBI systems can get backfires; running the stainless steel tubing that supplies the hydrogen down through the intake manifold to near the valves can help. And I know about nothing about using hydrogen with modern diesels with high-pressure injectors, etc, but if you could just hyboost those motors, you could ditch the DEF and get cleaner emissions. A properly configured hyboost engine actually cleans the air it breathes in (even the pollen for you allergy sufferers), especially in LA.
Sigh.....
a lot of research has been done into hydrogen generation using a process that mimics photosynthesis - actually there are two methods showing promise, very similar to each other using the photosynthesis mimicking method - I'm a firm believer that the research into solar panels and wind turbines are wasting time and money - small self contained hydrogen generators are the future of pollution free energy - on board hydrogen generators would virtually free people from the multi-greedy oil and gas empires and allow people to live almost off grind right in the middle of a city - here is a small blurb about just one idea out of pages of recent research into hydrogen generation - basically all it needs for energy is the sun -- Semi-artificial photosynthesis offers advantages over purely natural or synthetic routes to producing chemicals from solar energy, but devices based on it have remained elusive. Now, researchers couple a dye-sensitized photoanode with natural components to generate H2 photoelectrochemically from water without additional bias.
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