My internal combustion engine is more efficent than 30%

[smokingwheels]

What version of Turbocalc are you using?

Version 2.2

 

[smokingwheels]

How much oil was the engine burning at the time? I doubt the carbon on the plugs was from an overly rich mixture, agreed?

Knocking the bearings out is a sure sign of detonation, which is going to happen if you try to run high compression with low octane fuel; no surprise there.

Silicon?

The engine had no visible smoke from exhaust.
Yes the mixture was ok eg definably no black smoke or chugging from exhaust.

Silicon. my 2nd engine has had silicon put in it I had to remove the head to unblock the oil passage so that the cam could get oil again but it also damaged the bearings.
The plug of silicon was about 25mm long.

 

[mender]

Version 2.2

I have Version 2.3; where are you plugging in the numbers?

 

[mender]

The engine had no visible smoke from exhaust.
Yes the mixture was ok eg definably no black smoke or chugging from exhaust.

Silicon. my 2nd engine has had silicon put in it I had to remove the head to unblock the oil passage so that the cam could get oil again but it also damaged the bearings.
The plug of silicon was about 25mm long.

Silicone, as in RTV, not the metal silicon, right?

If there was no oil burning, then the carbon buildup is from incomplete combustion, i.e. not all the carbon atoms are combining with oxygen to form CO2 or even CO. You're wasting fuel energy, likely by having such late ignition timing to compensate for the excessive compression.

You'd be better off reducing the compression ratio and concentrating on increasing turbulence (swirl, quench, etc.) to get a better burn and make the engine less sensitive to detonation and plug fouling. You're concentrating too much on the expansion part of the cycle and giving up combustion efficiency - and damaging your engine. Also it appears that you consider ignition timing before TDC as evil; some will always be needed to get the mixture to burn and produce peak pressure at the right time but that can be reduced by increasing the burn rate (i.e. turbulence as mentioned).

 

[mender]

How much is this different to a normal car with a 2L engine and 1120kg dry mass?
Can you work out engine efficiency from this or not?

I know you have limited resources but to get some usable accuracy you should find some way of calculating the hp needed by your car at your test speed. You'll also need to keep good records of the weather conditions; a small change in wind direction and speed during a test will invalidate that test by skewing your readings. Otherwise you're only guessing.

How important is this to you?

 

[smokingwheels]

I have Version 2.3; where are you plugging in the numbers?

Go to the EFI section put in the kw then number of injectors 1 then mixture 14.7
Adjust the kw until you have matched you measured fuel flow.
Write down the kw then go to the turbo power enter engine config.
Set Boost pressure to 0 and Compressor efficiency to 2(has to be bigger than 0 or program error), turn off intercooler.
Now calculate engine and adjust VE% until you have the correct kw you found in the EFI section.
I have measured 2 fuel flows at different rpm eg 650 and 850 and its about 5% low but that probably because I changed the rpm without increasing VE%, this figure would have to increase with rpm to allow more air/fuel into the engine the error could also be my carby is running 5% rich.

Just had a coffee...
Once you know VE% you can then workout your change in rpm = kw then put kw into EFI and it will give you the fuel required cc/min from that eg .56kw = 3cc/min / 200 rpm= 0.015 cc/min per rpm for engine overhead. I would have to measure mine at several higher rpm points and see if it works out but for now its good enough.
The starter motor is rated at 1kw and drives 300 to 400 rpm on the engine, I would have to test and log the peak speed of the engine cranking with no spark to confirm that though but that is something I can do.

 

[smokingwheels]

I know you have limited resources but to get some usable accuracy you should find some way of calculating the hp needed by your car at your test speed. You'll also need to keep good records of the weather conditions; a small change in wind direction and speed during a test will invalidate that test by skewing your readings. Otherwise you're only guessing.

How important is this to you?

Thanks for the advise I am getting better since I found the http://www.weatherzone.com.au/"

My project is very important because my first engine would have been needed to be fired After Top Dead Center under load.
Here is a plot of my engine after I lowered the compression to ~8:1 from 12.5:1.
You will notice that the peak timing is reached by 1500 rpm which is normally 3000 rpm for my type of engine. After 1500 rpm the timing takes a dive back to ~20 deg BTDC this normally is about 2-3 deg up to the red line rpm. The values were tuned 1 step at a time over the rpm range so that most of them didn't knock, I did not understand much about tuning in 2003 because later on I found you got more grunt if you backed the timing off a little more and my programs had improved as well.

 

[JaredJames]

Thanks for the advise I am getting better since I found the http://www.weatherzone.com.au/"

My project is very important because my first engine would have been needed to be fired After Top Dead Center under load.
Here is a plot of my engine after I lowered the compression to ~8:1 from 12.5:1.
You will notice that the peak timing is reached by 1500 rpm which is normally 3000 rpm for my type of engine. After 1500 rpm the timing takes a dive back to ~20 deg BTDC this normally is about 2-3 deg up to the red line rpm. The values were tuned 1 step at a time over the rpm range so that most of them didn't knock, I did not understand much about tuning in 2003 because later on I found you got more grunt if you backed the timing off a little more and my programs had improved as well.

Are these actual measured values or approximations you've generated?

 

[smokingwheels]

Silicone, as in RTV, not the metal silicon, right?

If there was no oil burning, then the carbon buildup is from incomplete combustion, i.e. not all the carbon atoms are combining with oxygen to form CO2 or even CO. You're wasting fuel energy, likely by having such late ignition timing to compensate for the excessive compression.

You'd be better off reducing the compression ratio and concentrating on increasing turbulence (swirl, quench, etc.) to get a better burn and make the engine less sensitive to detonation and plug fouling. You're concentrating too much on the expansion part of the cycle and giving up combustion efficiency - and damaging your engine. Also it appears that you consider ignition timing before TDC as evil; some will always be needed to get the mixture to burn and produce peak pressure at the right time but that can be reduced by increasing the burn rate (i.e. turbulence as mentioned).

Yes Black RTV was found...

In my first engine it had 2 compression ratios 12.5:1 and 8:1.
I had plenty of power with the high compression engine but the spark plugs only lasted 3-4 days before shorting out with carbon.
In the low compression engine I was still replacing spark plugs every 2 months and it was on the edge of knock in certain rpm ranges but the correct Vacuum advance was not discovered until 2006.
I wonder how retarded you would have to run an engine to knock the plugs out in 150-200 km, I bet you would not be able to create wheel spin when turning a corner either.

I personally think turbulence is the wrong way to go we are dealing with an analog device.
I think turbulence=distortion.

What I have done seems (think? well my timing is way different) it changes the thermal expansion rate eg fire a approx square engine (Bore * stroke =) 65 Deg BTDC and see it it still runs forward without knocking and with a compression ratio ~10.5:1.
I found this site last night and plugged in the values for my engine (Green) and a normal engine (red) the result. I am not sure what I am looking at yet but when I fire 65 BTDC all my thermal energy is used up and the highest pressure of that eg the complete combustion cycle is very near TDC, I think this should cause a knock but it only runs a bit rough.

I think timing Before TDC is EVIL because you are compressing a rising energy eg you have to waist energy to compress the expanding gases instead of compressing a gas..Hope that makes sense.

Increasing burn rate hmm I think that would be like increasing distortion in my audio amp = not very nice. I could be wrong though.

 

[russ_watters]

This is good stuff:

I know you have limited resources but to get some usable accuracy you should find some way of calculating the hp needed by your car at your test speed. You'll also need to keep good records of the weather conditions; a small change in wind direction and speed during a test will invalidate that test by skewing your readings. Otherwise you're only guessing.

How important is this to you?

I have a $150 gadget that reads out my engine's operating parameters in real-time. On my way to/from work, there is a relatively flat 1-mile stretch of highway that has a very slight drop followed by a very slight rise, with a total of about a 15' difference in elevation from one end to the other. I've done loose tests with my car, but a more rigorous test method is not very difficult:

1. Make sure your fuel flow readout is calibrated. They are lookup-table based, not actual measurements.
2. Record the weather conditions. These are very important. Counter intuitively, I have found my car to be substantially more efficient at warm temperatures (70F) than cold temperatures (30F).
3. Make sure the car is fully warmed-up. This makes a surprisingly huge difference.
4. Enter the straight at a pre-chosen and set speed on your cruise control. For better results, run in both directions and average them.
5. Have a friend copy down the fuel flow rate every few seconds - or better yet, some products will record the data for you on a smart phone or laptop.
6. Average the fuel flow and calculate the input power.

Now you won't have a good baseline because you've already made some modifications, but since a typical car runs at somewhere around 30% efficiency, you should notice a massive difference between your car's fuel flow rate an the rated fuel efficiency of your car. Note, depending on your speed, you may notice a 10% better fuel economy just due to the fact that you are running at constant speed. EPA tests are run on a course with variable speed. Ie, my car is rated at 32, but I've seen as much as 35mpg - a difference of just under 10%.

 

[smokingwheels]

Are these actual measured values or approximations you've generated?

From what I can remember there values out of the program.
but I had a search thru my harddisk collection and found this I think its what I used because I would have to setup my program again eg feed in simulated rpm/calibration pc to check the timing accuracy.
The file is called coilone which I shortened to coil1 on the graph.

Anyway here is a copy of the mechanical advance from the program.

REM mec advance
DATA 5,5,5,5,5,5,5,5,5,5 : REM 250

DATA 5,5,10,10,10,10,10,10,10,10 : REM 500

DATA 10,10,10,10.2,10.4,10.6,10.8,11,11.3,11.6 : REM 750

DATA 11.9,12.2,12.5,12.8,13.1,13.4,13.7,14.4,15.5,16.5 : REM 1000

DATA 19,21,21.5,23.5,24.5,25.5,26.7,27.8,28.5,29 : REM 1250

DATA 29.5,30,30.1,30.2,30.3,30.4,30.5,30.6,30.7.30.8 : REM 1500

DATA 30.9,31,31,31,31,31,31,31,31,30.9 : REM 1750

DATA 30.8,30.7,30.6,30.5,30.4,30.3,30.2,30.1,30,29 : REM 2000

DATA 28,28,28,28,28,28,28,28,28,28 : REM 2250

DATA 27.8,27.5,27.2,27,26.8,26,22,22,22,22 : REM 2500

DATA 22,22,22,22,22,22,22,22,22,20 : REM 2750

DATA 20,20,20,20,20,20,20,19,19,19 : REM 3000

DATA 19,19,19,19,19,19,19,19,19,19 : REM 3250

DATA 19,19,19,19,19,19,19,19,19,19 : REM 3500

DATA 20,20,20,20,20,20,20,20,20,20 : REM 3750

DATA 20,20,20,20,20,20,20,20,20,20 : REM 4000

DATA 21,21,21,21,21,21,21,21,21,21 : REM 4250

DATA 21.5,21.6,21.7,21.8,21.9,22,22.1,22.2,22.3,22.4 : REM 4500

DATA 22.5,22.6,22.7,22.8,22.9,22,23,23,23,23 : REM 4750

DATA 23,23,23,23,23,23,23,23,23,23 : REM 5000

DATA 23,23,23,23,23,23,23,23,23,23 : REM 5250

DATA 23,23,23,23,23,23,23,23,23,23 : REM 5500

DATA 23,23,23,23,23,23,23,23,23,23 : REM 5750

DATA 23,23,23,23,23,23,23,23,23,23 : REM 6000

DATA 10,10,10,10,10,10,10,10,10,10 : REM 6250

DATA 10,10,10,10,10,10,10,10,10,10 : REM 6500


DATA 10,10,10,10,10,10,10,10,10,10 : REM 6750

DATA 10,10,10,10,10,10,10,10,10,10 : REM 7000

DATA 10,10,10,10,10,10,10,10,10,10 : REM 7250

DATA 10,10,10,10,10,10,10,-10,-10,-10 : REM 7500

 

[xxChrisxx]

I personally think turbulence is the wrong way to go we are dealing with an analog device.
I think turbulence=distortion.

He's talking about getting a more homogenous charge. Which would ensure a more even and faster burn. The more turbulent the inlet flow is, the more fixed the fuel and air become.

I think timing Before TDC is EVIL because you are compressing a rising energy eg you have to waist energy to compress the expanding gases instead of compressing a gas..Hope that makes sense.

Increasing burn rate hmm I think that would be like increasing distortion in my audio amp = not very nice. I could be wrong though.

The above is confusing and seems counter-intuative to me. Can you clarify what you mean by 'timing before TDC is evil' please.

If you allow over expansion you get a less clean and less efficient burn of the charge ni the cylinder. Ideally we would burn all the charge at the same time at a single descreeet point. However as it takes time for the flame to propogate we have to start the burn before TDC.

If you allow over expansion, you'll get incomplete combustion. Which would exlpain why you are constantly getting spark plugs caked in crap.

 

[mender]

I think it may be time to abandon the shotgun approach and impose some structure on your learning. Start with some basic engine theory books so you can see how what you're trying to do fits into the bigger picture.

I'd suggest getting "How To Make Horsepower Volume 1" by David Vizard. He presents things well and covers the essentials nicely. If you want more in-depth on how to develop a specific engine, his book "How To Modify Ford SOHC Engines" is about the Ford 2 litre 4 cylinder and the info can likely be applied to your engine. Another good book is "Power Secrets" by Smokey Yunick, again entertaining and informative. Lots more if you already have these.

If you're serious about engine theory, Heywood's "Internal Combustion Engine Fundamentals" is 900 pages worth of detailed analysis. I bought it on the recommendation of others here (was it you Chris?) and now refer to it quite frequently. Very nice having everything in one place but it may be a bit much as a starting book.

There are quite a few engine simulators (desktop dynos) that are more detailed than Turbocalc. What else are you using?

You may also find this interesting:
http://www.epi-eng.com/piston_engine_technology/thermal_efficiency.htm

 

[mender]

This is good stuff: I have a $150 gadget that reads out my engine's operating parameters in real-time.

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.

 

[xxChrisxx]

Smokey Yunick

lol.

 

[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?