Dyno numbers....

W5R, I posted plenty of pictures of my motor on this page and on my Facebook page openly. The people in the challenge seen my pictures, the people who actually count. But there was NO ENGINE SIZE RULE so even if I did go bigger I would just be going bigger. But my motor went from 242cc to 266cc.

What someone seen most likely is my 3.140" bore motor I posted on my Facebook page. What he fails to realize is that I have more than 1 motor. I have two 3.140" bore motors and pictures are posted on my page. I don't hide anything, but my bore size isn't labeled. But you can look at it, most people think they are regular 3" bore. But what this other guy is saying is that he can see my bore is .030" bigger than what I said, Hahahahahaha that's crazy. Ummm no, it's a 2.992" piston. I have YEARS of pictures posted, I can go back and screenshot old pictures of my motors. Originally it had a odd ball 2.980" piston in. So I rebuilt the motor with a 2.992" piston. The motor was 5 years old with rust in the bore.

Anyone else have years of pictures posted?? NOPE only me, the only guy with proof and don't hide anything.

Now since I'm already typing, let's see how many blocks I have on hand. A 2.992", another 2.992", a 3.031", 3.050", 3.140", another 3.140", 3.264" bore.
 
Minidragbike said:
W5R, I posted plenty of pictures of my motor on this page and on my Facebook page openly. The people in the challenge seen my pictures, the people who actually count. But there was NO ENGINE SIZE RULE so even if I did go bigger I would just be going bigger. But my motor went from 242cc to 266cc.

What someone seen most likely is my 3.140" bore motor I posted on my Facebook page. What he fails to realize is that I have more than 1 motor. I have two 3.140" bore motors and pictures are posted on my page. I don't hide anything, but my bore size isn't labeled. But you can look at it, most people think they are regular 3" bore. But what this other guy is saying is that he can see my bore is .030" bigger than what I said, Hahahahahaha that's crazy. Ummm no, it's a 2.992" piston. I have YEARS of pictures posted, I can go back and screenshot old pictures of my motors. Originally it had a odd ball 2.980" piston in. So I rebuilt the motor with a 2.992" piston. The motor was 5 years old with rust in the bore.

Anyone else have years of pictures posted?? NOPE only me, the only guy with proof and don't hide anything.

Now since I'm already typing, let's see how many blocks I have on hand. A 2.992", another 2.992", a 3.031", 3.050", 3.140", another 3.140", 3.264" bore.
Click to expand...

I was referring to what Wes said, where he took one of your pics and put into a computer program or something and compared the bore size with known bore sizes. If you think you are the only one who has been building these engines and taking pictures I think you are mistaken. I remember seeing a ton of pics from Sneaks over the years, of all sorts of engines, heads, everything, its not just you. Sneaks probably hasn't been doing it as long because he's older and had to learn technology and how to post pictures online.
 
W5R said:
I was referring to what Wes said, where he took one of your pics and put into a computer program or something and compared the bore size with known bore sizes. If you think you are the only one who has been building these engines and taking pictures I think you are mistaken. I remember seeing a ton of pics from Sneaks over the years, of all sorts of engines, heads, everything, its not just you. Sneaks probably hasn't been doing it as long because he's older and had to learn technology and how to post pictures online.
Click to expand...

Sneaks/Gary and I go way back, but I was doing it before him.

What WES said is, he seen 1 of my blocks on my Facebook page. He put it in some computer thing and says it's bigger than 2.992" bore. On my Facebook page I openly post up the size of specs of my engines, so he didn't have to go through all the trouble. Most likely what he seen was one of my other motors, because I have plenty of them. My challenge motor was my smallest motor.

The people that have known me over the year know I was the first to do a 3" bore. And they also know I do many for others and I own alot of 3" motors. I personally don't run anything smaller than a 2.992" bore, unless I'm building a stock size predator for a customer. So if you was to go on my Facebook page you may see about FORTY 3" bore blocks.

WES is saying I'm lying about .030" of piston size, which doesn't make any sense at all. I also deleted and blocked WES on my Facebook page simply because he came on 4cycle and called me a cheater and a liar. You can't make a statement like that when I know I didn't. Me being the first guy tested I had everything posted upfront. The guys after me can then say whatever they want. Soon we should have a 200cc motor that makes 35hp on Brads dyno.
 
Dang You"all sure know how to beat a dead horse.
MDB won he had the most Horsepower simple as that.
Give it a rest.
 
Here is a chart of the numbers you posted. The torque numbers are back plotted from the HP numbers. The difference in the low RPM numbers are a surprise. Still, if you slip the clutch at about 5000 RPM, the torque is the same. I don't know how much power you would lose from the heating of the clutch slipping it that much.

Light wheel, heavy wheel; what about gear ratio?? Don't you put more gear on the heaver kart?? If the acceleration time is the same, wouldn't that even things out?
 
How do you all feel about my suggestion that the wheels on acceleration dyno's feedback power to the engine at higher RPMs?

Back in the 70s, when I first heard of an acceleration dyno, it was attached to a ultimate loading device. In this case, a 471 Jimmy blower. They could vary the air intake so the engines would only accelerate to the rpm they would normally see on the track. They didn't even have computers hooked up to it, they just used a stopwatch. Make a run, make a change, and if the acceleration time to peak rpm was different, or was higher/lower, the change made a difference. Very crude compared to data acquisition by computer, but in the mid-70s there were no fast (very slow and no memory to speak of. A CPM computer was limited to 64K of memory.) personal computers or software.
 
For some reason this photo will not display any more, at least on my computer. Any one else having this happen? Are my photos being blocked?
 
bdomit01 said:
Let me know the results of you do Barry, curious for comparisons sake... I'm of the mind set that most very engine manufacturer are in the business of over stating their power output. If I were Honda then I would want to advertise my engine as the highest output of all 200cc utility engines haha, so I'm just not sure that's the most accurate way to calibrate a dyno.

For those that want a read I'm pretty sure SAE has published papers on the testing procedures for engine output, both inertia type and brake type. Might be worth looking into for those that are interested in how the manufacturers come up with their numbers...
Click to expand...
Honda GX200 are rated at 5.5hp @ 3600 on their own site http://engine.honda.ca/gx/horizontal_crankshaft/gx200/specifications
 
alvin l nunley said:
How do you all feel about my suggestion that the wheels on acceleration dyno's feedback power to the engine at higher RPMs?

Back in the 70s, when I first heard of an acceleration dyno, it was attached to a ultimate loading device. In this case, a 471 Jimmy blower. They could vary the air intake so the engines would only accelerate to the rpm they would normally see on the track. They didn't even have computers hooked up to it, they just used a stopwatch. Make a run, make a change, and if the acceleration time to peak rpm was different, or was higher/lower, the change made a difference. Very crude compared to data acquisition by computer, but in the mid-70s there were no fast (very slow and no memory to speak of. A CPM computer was limited to 64K of memory.) personal computers or software.
Click to expand...

Hi Al, the inertia dyno doesn't feed more energy to the engine because of the law of inertia. I.e. if you don't accelerate something, it will tend to stay at the same speed, it already has.
you can convince yourself of that pretty easily by letting go of the throttle in your car when accelerating; The car will stop accelerating. Exactly the same thing is true for the inertia dyno, which, if set up correctly, only measures acceleration. If you an inertia dyno does not give the same readings as a loading type dyno, it is because one of them are badly set up.
 
We have a new one that's been started. Same dyno tester, more entries. Testing will be in November.
Anyone who think they have the skills to win, let Brad know.
 
Vbruun said:
Hi Al, the inertia dyno doesn't feed more energy to the engine because of the law of inertia. I.e. if you don't accelerate something, it will tend to stay at the same speed, it already has.
Click to expand...
in order to illustrate what I'm saying, let's take an extreme view. Let's suppose, with adyno pull on an inertial dyno, that at 6000 RPM engine speed, we pull the spark plug wire. What do you suppose would happen? Do you agree that the engine would not stop turning over immediately, that the inertia (stored energy) of the wheel would drive the engine until the energy stored in the wheel was expended? My contention is that the wheel does this very same thing during the exhaust and intake stroke, just on a smaller scale. Why do you think they put flywheels on these little engines? One of the reasons; there are three obvious reasons, is to smooth out the power output at lower RPMs. The wheel on an inertial dyno does the same thing. With a four stroke engine, only one stroke is putting power into the crankshaft, it takes energy to push the exhaust out the valve, it takes energy to get air and fuel to flow into the engine through the intake valve and it takes energy to compress that air and fuel. So, one stroke gives you power and three strokes use power. The engine gets the power for those three strokes from the energy stored in the reciprocating parts including the flywheel.

The inertia dyno flywheel is simply another source of power feedback, just like the flywheel on the engine.
 
A load brake, water, hydraulic, magnetic, friction, does the same thing in the inverse. The load is still present during these strokes therefore would it not affect the readings. A dyno is simply a device to calculate how much work can be done in a given time. The inertia dyno depends more on the load and acceleration time. This is why it is stated as BHP (brake hp) if you want it in other terms IHP (Indicated), NHP (nominal),
 
alvin l nunley said:
in order to illustrate what I'm saying, let's take an extreme view. Let's suppose, with adyno pull on an inertial dyno, that at 6000 RPM engine speed, we pull the spark plug wire. What do you suppose would happen? Do you agree that the engine would not stop turning over immediately, that the inertia (stored energy) of the wheel would drive the engine until the energy stored in the wheel was expended? My contention is that the wheel does this very same thing during the exhaust and intake stroke, just on a smaller scale. Why do you think they put flywheels on these little engines? One of the reasons; there are three obvious reasons, is to smooth out the power output at lower RPMs. The wheel on an inertial dyno does the same thing. With a four stroke engine, only one stroke is putting power into the crankshaft, it takes energy to push the exhaust out the valve, it takes energy to get air and fuel to flow into the engine through the intake valve and it takes energy to compress that air and fuel. So, one stroke gives you power and three strokes use power. The engine gets the power for those three strokes from the energy stored in the reciprocating parts including the flywheel.

The inertia dyno flywheel is simply another source of power feedback, just like the flywheel on the engine.
Click to expand...
I can make a pull on my dyno and let off the throttle slightly in upper rpms and it will show a big drop in power in the curve. (not just level off, but DROP)
 
youngengines said:
I can make a pull on my dyno and let off the throttle slightly in upper rpms and it will show a big drop in power in the curve. (not just level off, but DROP)
Click to expand...

I would expect nothing else. What's your point?

Let me ask you a question that I've been wondering about. How do you end the pull? Do you just let off the gas at a certain RPM? If you let off, (I'm assuming you do) what would happen if you didn't let off?

On the track, do you gear to reach a certain RPM? If you gear lower, say one tooth on the axle, does the engine pick up about 100 RPM? If you gear one tooth even lower, does it pick up another hundred RPM?

The point I'm trying to make is; at some point on the track, as you keep adding gears to the axle, the engine, because of dynamic loading and a drop in horsepower, will stop gaining RPM at that point. Will it do that on the acceleration dyno? I've never done it myself, but I'm pretty sure you would see the same thing with a dyno that had an ultimate loading device.
 
Kart43 said:
A dyno is simply a device to calculate how much work can be done in a given time.
Click to expand...
A small correction; the dyno does no calculating, it only measures torque, it then then sends that information to the recording device with the rpm it was turning at the time it took the measurement. The computer, if there is one, calculates the HP using the measured torque (break dyno) and the rpm at which it was measured. A good computer program would also include the air density (barometric pressure and temperature) for correction factors, in its calculations.
 
youngengines said:
Here is the dyno info (from my dyno) on the stocker I took to the dyno challenge.. I hope to figure out how to post this stuff better, as I have the info from the other engines as well...
Click to expand...
With nothing else to do and nowhere to go, I did this.

A stocker? That peak torque is at a higher RPM than I would have expected.

Do you not have torque numbers? Calculating them takes a long time
 
alvin l nunley said:
With nothing else to do and nowhere to go, I did this.

A stocker? That peak torque is at a higher RPM than I would have expected.

Do you not have torque numbers? Calculating them takes a long time
Click to expand...

Yes, it has torque numbers, but I rarely look at them. The engines I build will never see that low of rpms..except when pulling on the track.
 
youngengines said:
Yes, it has torque numbers, but I rarely look at them. The engines I build will never see that low of rpms..except when pulling on the track.
Click to expand...

Sorry about the low numbers, but you included them in your print out so I included them in the chart. Next time I'll I'll be sure not to include them. At what rpm would you like the chart to start?

So, you've found something wrong with the chart, did you see anything good in it?
 
alvin l nunley said:
Sorry about the low numbers, but you included them in your print out so I included them in the chart. Next time I'll I'll be sure not to include them. At what rpm would you like the chart to start?

So, you've found something wrong with the chart, did you see anything good in it?
Click to expand...

I didn't find anything wrong with your chart.. I actually think you are very smart, and whatever you do.. you do well.
 
You must log in or register to reply here.
Back
Top