My internal combustion engine is more efficent than 30%

[mender]

lol.

Is that a good or a bad lol? Most recognize his contributions but wonder about the hot air engine.

 

[smokingwheels]

Ok I am learning heaps my brain hurts sometime so I stop for a coffee, after what Russ so kindly said I started to look at the data I do have.

You can grab a copy at "ftp://203.161.71.130/Engine%20Data/Raw%20Data/"[/URL] If you want the files are CITY.csv, CITY1.CSV, CITY2.CSV and CITY3.csv.

The values are at 1 second intervals and instantaneous values.
The header is RPM, time of day in seconds and vacuum advance.
If the vacuum is 20 then its above 300mm of Hg.
If the vacuum is 15 then its just below 300mm of Hg.
If the vacuum is 0 then its about 200 mm of Hg.

Then you have an idea of what I have posted on my forum [URL]http://203.161.71.130/Forum"[/URL] under fuel consumption.

I did a rough calculation last night and found from the data CITY3.CSV and the idle eg no load fuel tests I have done it only takes on an average 1.68 kw to do 40.95 km/h rear wheel power, I have no idea how good that is for a car with a dry mass of 1120 kg

What I can calculate is the fuel used at no load over the trips and then see how much is left pushing the car along over the test period also from the vacuum I maybe able to guess at fuel consumption.

Anyway I have a program to write to analyze my data from my trips this will keep me busy for a little while I can also generate an engine acceleration figure to but its uncalibrated.

 

[smokingwheels]

I need some one to check my research notes and evidence because...

I rang the Sarich corporation and got the dyno figures for my cars mass. Thanks to them.

The dyno load for 80 km/h is 6.7 kw so at 40.95km/h = 0.5118 times less so 6.7kw * .5118 = 3.475kw there maybe some error for wind drag not in my favor?

So on average I used 1.68 kw of fuel and drove at 40.95 km/h when the load is 3.475 kw on the dyno?

Is it I have roughly double the torques with the same fuel?
I can scan my 2 pages of calculations for you to see where I may have gone wrong?

I have measure my no load fuel consumption at 3 points then worked out consumption per rpm
then used that rate at a higher rpm to get no load fuel consumption I then worked out what was left for the trip and it works out to be an average power of 2.4kw at the engine.

 

[xxChrisxx]

Is that a good or a bad lol? Most recognize his contributions but wonder about the hot air engine.

He's just funny character on the motorsports landscape.

It's almost 100% certain he was a bullgarbageter, and was mostly successfull through the tactical use of not obeying the rules. The fact that in scrutineering he always had to change something for the car to be legal (on saying that no legal car has ever won a motorrace grey areas are part of the fun) I wouldn't point to him as an example of how to change something in a scientific way though.

An interesting chap non the less.

 

[smokingwheels]

I have a scan gauge that plugs into the OBD2 port and shows what the ECU is doing in real time. Quite fun to play with.

Thats a great idea but where would it plug into on my carby LOL!

 

[mender]

He's just funny character on the motorsports landscape.

It's almost 100% certain he was a bullgarbageter, and was mostly successfull through the tactical use of not obeying the rules. The fact that in scrutineering he always had to change something for the car to be legal (on saying that no legal car has ever won a motorrace grey areas are part of the fun) I wouldn't point to him as an example of how to change something in a scientific way though.

An interesting chap non the less.

Running the officials around was part of the game, but there was a solid core behind the show. His exploits tend to get mentioned more than his research though.

 

[smokingwheels]

Running the officials around was part of the game, but there was a solid core behind the show. His exploits tend to get mentioned more than his research though.

Thanks mender maybe I should start a new thread called please explane my new toy and offer the officials one tiny bit of info at a time so as not to make them just say its impossible when hitting them with too much change.

eg why is my peak idle (no load) rpm achieved when I fire 30 - 40 degrees BTDC?
see http://203.161.71.130/forum/topic.asp?TOPIC_ID=14"

 

[xxChrisxx]

Thanks mender maybe I should start a new thread called please explane my new toy and offer the officials one tiny bit of info at a time so as not to make them just say its impossible when hitting them with too much change.

It's becuase your problems with this are listed below. Please realize that I'm not saying this just to put you down, I don't want you to dismiss it becuase it's not what you think. I really want to help becuase I

You don't appear to know enough theory to realize what changes mean. This is evident with fairly clumsy use of numbers, calculations that don't really make sense. (Also your Carnot cycle thread shows this).
You don't appear to have a clear goal and targets for your testing regieme.
There doesn't apear to be any structure to your changes.
Unless I've missed something, you are only testing at idle. Which isn't even preresentetive of real world conditions.

The basic fact is, you are never going to get a great deal of efficiency gains out of messing with timing or fuel trim or even compression. Engines have been round for donkeys years now, you are not doing anything different to what has been done many times before.

You aren't making sweeping changes to the engine, they are relatively simple. So it's highly unrealistic to expect large changes in efficiency. As someone would have discovered and implemented it before.

You persist in that we are just doubting you. Look at the responses you've got so far in this thread and the Carnot thread. When everyone is telling you the same thing, you have to ask yourself, maybe they are right.

We can't help you with what changes to make, as you seem to have a fairly good grasp on the physical changes. We can help you to make a well structured, methodical test regieme and help interpreting results.

 

[smokingwheels]

It's becuase your problems with this are listed below. Please realize that I'm not saying this just to put you down, I don't want you to dismiss it becuase it's not what you think. I really want to help becuase I

You don't appear to know enough theory to realize what changes mean. This is evident with fairly clumsy use of numbers, calculations that don't really make sense. (Also your Carnot cycle thread shows this).
You don't appear to have a clear goal and targets for your testing regieme.
There doesn't apear to be any structure to your changes.
Unless I've missed something, you are only testing at idle. Which isn't even preresentetive of real world conditions.

The basic fact is, you are never going to get a great deal of efficiency gains out of messing with timing or fuel trim or even compression. Engines have been round for donkeys years now, you are not doing anything different to what has been done many times before.

You aren't making sweeping changes to the engine, they are relatively simple. So it's highly unrealistic to expect large changes in efficiency. As someone would have discovered and implemented it before.

You persist in that we are just doubting you. Look at the responses you've got so far in this thread and the Carnot thread. When everyone is telling you the same thing, you have to ask yourself, maybe they are right.

We can't help you with what changes to make, as you seem to have a fairly good grasp on the physical changes. We can help you to make a well structured, methodical test regieme and help interpreting results.

Thanks for the input

I have been working through the data and learning you are right I do not know much about the theory and most of the time I haven't a clue what is going on but I can now say I have shifted or moved the slope of the line for load vs efficiency. I now don't think I have a more efficient engine but I have moved the efficiency slope higher in the lower range so I must have taken it from some where eg my full throttle efficiency is low because my engine ingests roughly 2 times the fuel and air at high rpm eg a 2L engine consumes inexcess of 1 L/min but I would have to confirm that figure again.

I have done more calculations and compared engines for the first time in terms of efficiency of the power stroke see post under load see post #20 on this page https://www.physicsforums.com/showthread.php?t=480029&page=2"

Does anyone know of a place on the net that would list all variables I need to measure and test for the improvements I have made to my engine, oh and free?

 

[mender]

Does anyone know of a place on the net that would list all variables I need to measure and test for the improvements I have made to my engine, oh and free?

The efficiency of the engine is gauged by the amount of usable energy generated per unit of fuel used. You need to measure how much work the engine is doing against how much fuel it is using while doing that work - no guessing!

That's what I told you earlier. Once you are able to accurately and repeatedly measure those two things, you can start evaluating your changes.

Here's your homework:
http://autospeed.com/cms/title_Brake-Specific-Fuel-Consumption/A_110216/article.html

There will be a test.

 

[mender]

eg why is my peak idle (no load) rpm achieved when I fire 30 - 40 degrees BTDC?

Because that releases the most energy the most efficiently for those conditions. It also proves that having the spark occur well before TDC is not evil but necessary. You need to accept that fact and then learn why, so you can move on.

 

[brewnog]

Does anyone know of a place on the net that would list all variables I need to measure and test for the improvements I have made to my engine, oh and free?

Easy.

Under steady state conditions, measure the power your engine is producing (or measure the speed and torque). Under those same conditions, at the same time, measure how much fuel is being consumed by the engine. Repeat this until your between-measurements variation is less than, say, 2% of your measured figures.

Then post both those figures, along with the fuel type. If you want to make comparisons, run the same engine under the same conditions with your modifications made.

I'll tell you your efficiency, and I won't even charge you for it. Deal?

 

[jambaugh]

Does anyone know of a place on the net that would list all variables I need to measure and test for the improvements I have made to my engine, oh and free?

Buy, rent, or borrow one of these: http://www.taylordyno.com/catalog/engine-dyno" . (An engine repair facility in your area should have one. Whether they'd let you use it is a different matter.)

Hook it up to your engine.

Hook up a fuel metering device.

Measure the volume of fuel consumed for a given period of time, at a given power output.

Power x Time = Energy

Energy/Fuel Amount = Efficiency.

Energy/ Energy in that fuel = % Efficiency.

Repeat a few times for each load level and at different load levels (output power).

 

[smokingwheels]

Buy, rent, or borrow one of these: http://www.taylordyno.com/catalog/engine-dyno" . (An engine repair facility in your area should have one. Whether they'd let you use it is a different matter.)

Hook it up to your engine.

Hook up a fuel metering device.

Measure the volume of fuel consumed for a given period of time, at a given power output.

Power x Time = Energy

Energy/Fuel Amount = Efficiency.

Energy/ Energy in that fuel = % Efficiency.

Repeat a few times for each load level and at different load levels (output power).

Thanks for the tips

I don't repeat a test until I have made an improvement.
When this condition is false I will repeat a test.

Buy, rent, or borrow and steal...
I won't be able to afford to fuel to run my engine for 4 months at the moment so I will have to work on something else until then.

I would need a machine that measures the power of the torque pulse from every cylinder instead of a dyno and would need similar type of measurements to see what the drive train is doing.

Thanks Physics Forum peoples for all your help, I am working on my ignition controller now for a while.

In electronics if you know or measure 2 variables you can then calculate the the 3rd there is a law that covers that.

Why in an engine any different?

 

[xxChrisxx]

In electronics if you know or measure 2 variables you can then calculate the the 3rd there is a law that covers that.

Why in an engine any different?

It's not, it's a maths thing. For a problem to be solvable you need as many equations as you have unknowns.

So if you have an equation with three variables. If you know two, leaving one unknown you can solve it. If you have four variables and know two, you have two unknown and can't solve it until you have a second equation with one of the unknowns in.

In te case below of.
Energy / Fuel amount = Efficiency.
Power * Time = Energy

We have an equation that looks like this:

Power * Time / Fuel Amount = Efficiency.

If we measure power on a dyno and we measure fuel amount and we measure time. We know three of the four variables, so can solve the equation.

I would need a machine that measures the power of the torque pulse from every cylinder instead of a dyno and would need similar type of measurements to see what the drive train is doing.

An engine dyno measures torque and rpm and calculates power. As:
Power = Torque * Angular Velocity.


Whilst you are not able to conduct more practical test, here is some food for thought.

Comparing things like power output or fuel consumption are poor ways to compare different engines in terms of efficiency. You want to use things called 'non dimensional' comparisons. This is where outputs and variables are converted to a standard forn that can be directly compared.

Two to read up on are.
Mean Effective Pressure - http://en.wikipedia.org/wiki/Mean_effective_pressure
Brake Specific Fuel Consumption - http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption

These two variables can be used to directly compare engines. They use easy to measure variables.

 

[jambaugh]

I would need a machine that measures the power of the torque pulse from every cylinder instead of a dyno and would need similar type of measurements to see what the drive train is doing.

No, you need a device to measure the power output of your engine under load. Note that dynamometers can be used for either engine output measurements to calculate fuel to work conversion efficiency, or power train output to calculate transmission efficiency. Both are the same problem... what is the output power vs input power?

In electronics if you know or measure 2 variables you can then calculate the the 3rd there is a law that covers that.

Why in an engine any different?

An engine is a converter of one form of energy to another. What you are doing is comparable to designing a better solar panel or electrical generator, or electric motor. You measure the input, measure the output and get a ratio efficiency.

You want to calculate efficiency but the comparable calculation for an electronic device is quite involved typically invoking some substantial physics and typically only an idealized calculation, not reflecting real imperfect materials. Similarly with the engine.

The ultimate proof is in the pudding, what power is delivered to the crankshaft under load as compared to what rate fuel is being consumed. You cannot circumvent the need for this empirical test to determine actual efficiency. Only such an empirical test can support a claim of improved efficiency. Only such will tell if your modified engine will get you from Atlanta to New York using less fuel.

 

[smokingwheels]

No, you need a device to measure the power output of your engine under load. Note that dynamometers can be used for either engine output measurements to calculate fuel to work conversion efficiency, or power train output to calculate transmission efficiency. Both are the same problem... what is the output power vs input power?An engine is a converter of one form of energy to another. What you are doing is comparable to designing a better solar panel or electrical generator, or electric motor. You measure the input, measure the output and get a ratio efficiency.

You want to calculate efficiency but the comparable calculation for an electronic device is quite involved typically invoking some substantial physics and typically only an idealized calculation, not reflecting real imperfect materials. Similarly with the engine.

The ultimate proof is in the pudding, what power is delivered to the crankshaft under load as compared to what rate fuel is being consumed. You cannot circumvent the need for this empirical test to determine actual efficiency. Only such an empirical test can support a claim of improved efficiency. Only such will tell if your modified engine will get you from Atlanta to New York using less fuel.

"The ultimate proof is in the pudding" ok done a rough estimate if I could drive fairly constantly without too many hills at 60km/h I could do it Atlanta to New York 1418 km if I had a 20 L jerry can on board. It begs the question I will use overdrive on my next test to see if it is any better and will recalibrate one of my load sensors as well but that will be at the end of july now before I can retest any of my theory's.
Oh I can also push my engine to hard knocking without piston damage but the crank takes a beating though.

Unless some one sponsors me I will never get my engine on a dyno.

 

[xxChrisxx]

"The ultimate proof is in the pudding" ok done a rough estimate if I could drive fairly constantly without too many hills at 60km/h I could do it Atlanta to New York 1418 km if I had a 5 L jerry can on board. It begs the question I will use overdrive on my next test to see if it is any better and will recalibrate one of my load sensors as well but that will be at the end of july now before I can retest any of my theory's.
Oh I can also push my engine to hard knocking without piston damage but the crank takes a beating though.

Unless some one sponsors me I will never get my engine on a dyno.

I really don't want to seem like we're just bashing you.

A 'rough estimate' is not proof or evidence in any way, shape or form. By continuing to test in the way you have been doing, you are just wasting time and money. By not doing all these useless tests that tell you nothing concrete what so ever, you could have saved the money to do a proper dyno test.


Let's look at the bottom line here.
How much have you spent?
What data have you gathered?

By data, I do not mean speculation or estimates. What concrete data do you have?

 

[mender]

Oh I can also push my engine to hard knocking without piston damage but the crank takes a beating though.

This is not a smart thing to do; forcing your engine into detonation is a sure way to deplete what little funds you have. It also doesn't improve the efficiency, so there is no reason to continue doing that.

Stop it!

 

[smokingwheels]

ok Change of subject Gensets and there fuel consumption.

Rough figures

2.5 kva 5.5 HP 163 cc engine at 3600 rpm with 2kw load 15 L will last 6.5 Hours

So that is 38.46 cc/min with approx 2.4kw output (80% generator efficiency??).

The turbocalc program calculates fuel for 2.4kw at 13.26 cc/min.
Thus 30% efficient so times 3 to get 39 cc/min of fuel for 2.4 kw output out of engine.
So what I am trying to say, I think this program is correct.

Anyway a normal 4 cylinder engine uses 5 hp of fuel 20cc/min just to get to 750 rpm.
To output 5hp@750rpm would it need another 20cc/min = 40cc/min.
or is is 3 times 20 cc?

My engine uses 12cc/min for 750 rpm.
to output 5hp@750rpm it would need another 12cc/min =24 cc/min
or is it 3 times 12cc?

I have a problem!
Im giving up an going to collect data from other peoples cars I have a draft form at http://smokingwheels.dyndns.org"

I was thinking of betting 1 dollar if you can beat me on my test track in similar EFI car...
Gives me something to do instead of playing with figures.

...have att form...What am I missing from the drivers point of view?

 

[brewnog]

You've been told this already, but the amount of fuel used at idle is just not a way to compare what the fuel efficiency is like on load. To infer the fuel consumption on load from a fuel consumption at idle is irrelevant, meaningless, negligent, incorrect, wrong, and completely pointless.

 

[Bob S]

...2.5 kva 5.5 HP 163 cc engine at 3600 rpm with 2kw load 15 L will last 6.5 Hours

So that is 38.46 cc/min with approx 2.4kw output (80% generator efficiency??).

The official conversion used in BSFC (brake specific fuel consumption) maps is

100% efficiency ≡ 83 grams gasoline per kW-hr.

See http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption

"Certification gasoline = 18,640 BTU/lb (0.01204 kW·h/g)" = 83 grams per kW-hr

So a 100% efficient 2.4 kW engine should use 3.32 grams per minute, or about 4.5 cc per minute. This implies that your engine is ≈12% efficient.

The BSFC map in the above pdf shows a 40% efficient engine, with a minimum fuel consumption of 206 grams per kW-hr.

See table in above pdf for table of engine efficiencies. In particular note the Toyota Prius engine at 37% efficiency.

Bob S

 

[jambaugh]

"The ultimate proof is in the pudding" ok done a rough estimate if I could drive fairly constantly without too many hills at 60km/h I could do it Atlanta to New York 1418 km if I had a 20 L jerry can on board. It begs the question I will use overdrive on my next test to see if it is any better and will recalibrate one of my load sensors as well but that will be at the end of july now before I can retest any of my theory's.
Oh I can also push my engine to hard knocking without piston damage but the crank takes a beating though.

Unless some one sponsors me I will never get my engine on a dyno.

The drive test may indicate a qualitative improvement (or disimprovement) but you really need some numbers. So if you can't afford a dyno, make one. Probably the cheapest thing to do is fix a setup so your engine is vigorously stirring a big drum of water sufficiently to generate an appreciable load.

To calibrate it,
* measure the volume of the water in cubic meters,
* measure the initial temperature in deg. C,
* run the apparatus for a minute or so but measure the time to the second (100 seconds is a nice round number),
* measure the temperature afterwards and determine the change in temperature.

1 Calorie = 1000 calories = energy needed to raise the temp of 1m^3 of water 1 deg C.
= 4.184 kiloJoules = 4.184 kilowatt seconds.

This will allow you to calculate power output at a given engine RPM with your setup.
Follow this procedure for each run and carry out several runs at different RPM's.

Once you've calibrated the load you can then run the engine at constant load calculated for that RPM. Run it for 30min or so and measure the fuel consumed per calculated Joule of energy output and thus calculate explicit efficiency.

This setup should be quite accurate but the precision depends on your measurements. Try to find the calibration time which gives you a good temperature change but be sure your initial temperature is the ambient temperature, and it will help if you be sure the can is covered as much as possible to prevent evaporation loss. Insulation around the water drum would also help. Also the stirring apparatus should agitate the water but you want to make it turbulent, something like an egg beater or butter churn. But be sure no water sloshes out. (I recall once seeing a fellow tuning up the the outboard on his boat by running it in an drum of water in his back yard.)

Basically this is reproducing Joule's experiment measuring the http://en.wikipedia.org/wiki/Mechanical_equivalent_of_heat"

 

[HowlerMonkey]

Our dyno uses twin eddy current retarders.

https://www.youtube.com/watch?v=5VkDLfmGH7Y

That's only a 1300hp pull but it was enough to go from 0 to 252.9mph in a mile from a standing start.

We're finishing a 2500hp engine for some world record runs.

Engine management systems of today's EFI cars have the ability to display a relatively accurate mpg...unless the manufacturer purposely skews the data to show more favorable mileage.

They use injector pulse width, rpm, grams per second (from mass airflow sensor), gearing, downstream monitoring of exhaust gases, and the fuel trim correction values.

Miles per gallon increases require optimizations in many areas but the hardest area to optimize is the driver.

I've seen guys get 18mpg in a prius because the driver drove in such a way that he defeated any of the benefits of his car's design.

 

[smokingwheels]

Would exhaust manifold temperature tell how efficient an engine was?

My engine which has a cast manifold and I have a normal engine but its got extractors.
Problem..
Can I compare the two?

Test setup:
My engine temperature was about 95 deg C and warmed up and idling, the ambient temperature was 12.9 deg C, wind W25 km/h and wind gusts 43 km/h.
The Second engine temperature was below 88 deg C and still warming up, the ambient temperature was 9.5 deg C, wind W 29 km/h and wind gusts 52 km/h.
I melted 60/40 Solder on the exhaust path about 3-5 inches away from the head with the engines idling after going for a drive to warm them up.

My modified engine took some time to melt the solder the second engine did it really quickly with the flux smoking well.

I was wondering if its because of the extractors being thinner and less surface area would it be hotter?
With more surface area for the cast iron manifold would it run cooler?
Will ambient temperature affect the manifold temperature a lot or not?
The ambient temperature dropped after testing the modified engine.

I have a Video play list if you are interested to see the results from 4 short clips.
http://www.youtube.com/playlist?list=PLA7848D3EF5B27FF3

Solder (60/40) melts at 370 deg F and a soldering iron is about 700 deg F.
My engine with the cast manifold took quite a while to just melt the solder with not much smoke from the flux.

The other normal engine with the extractors did it very quickly and the flux was rapidly turned into smoke in a similar way to a soldering iron from my experience.
I know I need 2 of the same to compare so I need to find a few volunteers in Australia if
possible.

 

[brewnog]

So you're using solder as instrumentation while doing tests on two different engines under two different conditions at idle?

Firstly, thermocouples are the way to measure exhaust temperatures on engine test. You can get them for less money than you probably spent on your solder. Melting solder (and trying to draw a conclusion about the way it melted) doesn't tell you anything, except that the exhaust pipe is hot. It doesn't even give a good indication of the temperature of the exhaust gas!

Secondly, (and we've been through this before, but I'll say it again because it seems to have soaked in like water off a duck's back) performance indicators at idle tell you so little about what your engine is doing that when doing engine development work, we hardly ever take data at idle. It just doesn't tell you anything about what the engine will do under operation.

Thirdly, what do you mean by 'extractors'? The only exhaust extractors I've come across are ventilation systems for taking combustion products out of the test cell.

Finally, what are you trying to determine now?

 

[smokingwheels]

Thermocouples Ok but I would have to get a hole drilled and a fitting welded to my exhaust.

An engine under load is what's needed.

"what do you mean by 'extractors'?" They are smooth mandrill bent tubing providing a rounded flow for the exhaust gasses also usually larger than cast iron counter parts and they are freer flowing.

"Finally, what are you trying to determine now?"
To see if there is a relative difference between the two engines I guess I will have to find a similar engine setup to compare to mine.

I don't have any money to play with, I guess that is what my trouble is and why I don't give up.
Another reason I don't give up is my car has done a trip at 80 km/h one night and got a fuel consumption of around 4.1 L/100 km, worst case is as high as 5 L/100 km this is dependent on the slope of the pavement where I filled up, its about a 3L variation on a full tank from tests I've done since, so I am discounting if I got less fuel when I filled up that night. My consumption would of been around 3.3 L/100 km, I have a witness or two but I doubt if they would talk to me again (x girlfriend and her x husband). That 71 US MPG I serious do not think I can reproduce that ever. I have shelved my engine thing for a few months now maybe a bit longer is needed. But I could try and contact the x husband some how.

 

[jambaugh]

smokingwheels,

If you don't want to build/buy a dynamometer, and you have the engine mounted in a working vehicle, I would suggest you hook up an auxiliary fuel tank (which allows you to measure precise fuel usage), take it on the highway and make a few trips with and without your modifications. To be more scientific you could have someone else do the driving, not letting them know whether you do or do not have the mod installed. Try to drive at constant speed and work up the average mileage with and without the mods. See if there is a significant difference in fuel economy which will indicate whether there is a significant difference in fuel efficiency.

Be sure you use the same type of fuel each time. Look http://www.epa.gov/fueleconomy/data.htm" for information on what variables can affect fuel economy so that you can minimize variations and get good data.

And I'll repeat again what everyone has been telling you:
Performance information at engine idle is useless! You must test the engine under load!

 

[HowlerMonkey]

This one got a LD28 with a turbocharger for a while before going back to gas...and a turbo.

Post is related because it's the same year and model as being discussed.

http://princemakaha.homestead.com/files/IMG00069.jpg