Dyno's running, now what?

GT6Steve

GT6Steve

Well-known member
Joined
Jul 13, 2008
Messages
751
Location
Las Vegas Nevada
Friends,

I have recently purchased a G0-Power water brake dyno for the shop. Yesterday I ran it for the first time and got repeatable results but I have no Stinkin' idea how to run a test.

Can anyone point me to some learnin? I'm a scientist by nature so this is going to be a good tool.

Anybody know what SAE J606/607 means?

Thanx in advance...Steve
 
Depends on what type of brake you have. Basically there are two types, namely constant volume waterbrakes & constant fill waterbrakes.

The first one uses 'sluices' to control the amount of resistance the brake creates and with the latter the resistance is controlled by the amount of water in the brake.

The way you operate the brake depends on the type of test you are doing.

If for instance you would like to check the power the engine produces at a certain rpm, you would bring the engine to, say 3000 rpm. Then you would increase the resistance of the brake = increase the load on the engine. Each time you increase the load, rpm will drop and you will have to adjust by giving it more throttle.
At a certain load, the rpm will not increase anymore. This is the point of maximum torque and that is the torque of the engine at that rpm point.

Second way of testing is with a certain fixed load and then you accelerate the engine from say 1500 to maximum rpm. You measure the time between the 1500 and say 7000 rpm point and with the fixed load you can calculate horsepower.

There is much more to it, but basically this is the idea.

I'm overhauling an old Heenan Froude Sluice dyno and at the same time trying to digitize it. Not the most simple project, since it requires me to purchase some DAQ equipment and the necessary servo's to automatically adjust both load and throttle with a pc. Furthermore you normally need a pretty powerfull pump to keep the dyno at its designed temperature range (if the water starts boiling it creates cavitation which will pretty soon start destroying the dyno inside, and trust me i've seen the result of cavitation on my waterbrake). And even then, to get accurate repeatable results you would need to have sufficient air cooling to the testroom and be able to cool the engine down etc...
 
Last edited:
Thanx immensely, That's the best info I've gotten yet. I've only had it for three weeks and yesterday was the first time it actually ran. Rear seal leaks like a sieve but at least it runs.

thanks for your input, Steve
 
GT6Steve said:
Thanx immensely, That's the best info I've gotten yet. I've only had it for three weeks and yesterday was the first time it actually ran. Rear seal leaks like a sieve but at least it runs.

thanks for your input, Steve
Click to expand...

Is it digitized yet ?

BTW : check the wikipedia website,the explain for the different test methods.

I also have some papers of engineers that explain this in detail, but the problem is, they are in dutch, so i don't think they will help you out, unless there is a programm that lets you translate trough pdf files
 
Last edited:
No data aquisition at all yet. Just gauges.

I'm an instrumentation and process control guy professionally so you'd think DAQ would be easy but all of our front end stuff is too expensive for home. I'm looking to use Opto 22 modules and Labview down the road but that's still vague.

So far I've identified at least a dozen Thermocouple points I want to monitor and I've not even thought (or comprehend) automated loading.

I have so much to learn....
 
All I can say is it would be a GREAT spot for me to hang around and help out, learning something along the way.....too bad you not in NE Florida....hell, I"d do it for FREE...:crutches:
 
Gene,

Have you got experience in automation ?

Steve,

Watching the thermocouples is the most important thing on these things as is pressurecontrol.

Load measurement is done with an S-beam mostly, which goes through signal conditioning and ends up in the pc to be processed.

The thermocouples could also be handled with a plc system if that's easier to you.

Remember that you also need some way of controlling the load of the waterbrake and the throttle. In my case i'm using servo's. Since these need controllers, things get pretty expensive.
If yours is the constant fill type, you would need to control the amount of water that enters in the waterbrake,so this means monitoring pressure real close and having a fast acting electronic valve.
 
Ok guys, keep posted. I'm working towards getting mine working. The axle is in for chroming the bearing surface and balancing. I've just bought a couple of national instruments pci 6024e cards and i'm working on getting my servo with controller working (for the sluices).

I'm still looking for a second hand desktop pc since all i have is laptops that won't work with the pci's
 
Just an update,

Last Sunday afternoon I fired up the mule on the dyno for some more learning. Looked to get a water pump flow value from the new GPM rotameter installed. Nothing extensive, just another familiarization test run...Yeah, right.

Everything started well and idled smoothly as I brought the throttle open applying load. Wired the throttle at WOT and had a stable load at 2000 RPM. About 92 Ft/Lbs on this old street 2000cc motor so we're not in the stratosphere.

Just recorded those numbers and turned to the load valves to raise the RPM when I heard a Bang. Instantly I was out the door and hearing the engine go to MAX revs behind me so I knew I'd lost the connection somehow. I circle back thru the office and I can see sparks from the containment shroud. Ooh, bad. Run around the front of the engine and grab a hand full of wires just as I hear a dull thud and the forty pound driveshaft slams against the dyno frame a few feet ahead of me. After bouncing off of the yellow racer.

Brothers, I had the livin' sh*t scared out of me!!!

If not for the driveshaft containment shroud (that failed) I could've died!

Turns out the massive driveshaft is attached to the dyno input flange by eight 1/4-20 SHCS. Of which two were already broken and ignored.


I've got plans to move forward, the driveshaft is being repaired but I'll likely not use it again.

I'm studying a bellhousing to brake adaptation that will be restrictive but safer.

Point is, these things are dangerous, be safe!
 
This is exactly why i'm trying to configure mine so that i don't need to be in the testing room. Thru the data acquisition I can control things so in the event something goes wrong the engine is immediatly shut down.
 
Belgian1979vette said:
This is exactly why i'm trying to configure mine so that i don't need to be in the testing room. Thru the data acquisition I can control things so in the event something goes wrong the engine is immediatly shut down.
Click to expand...

As a backup, I would have me a big old light switch up top of the console, wired with 8 ga wire to the main ignition power, flip that switch and ign goes by by.....

damn if I"d trust drive by wire...:clobbered::hissyfit::censored:
 
Wow! That would scare the shit out of me, literally.

Do you know what kind of water pressures and flow rates you are generating?
 
BBShark said:
Do you know what kind of water pressures and flow rates you are generating?
Click to expand...

Not precisely. It's on a 3 HP well pump thru a 5/8" garden hose at about 40 PSI. I'm still experimenting with the appropriate restrictions in the discharge hoses to control in my HP range. I expect to be able to stall the engine when it's correct but maybe not. We'll see.

Got some work to do now before I can try again.

Ironically, I have a big red mushroom head E-Stop buton to insert into the 12 volt ignition system as well as an RPM activated switch. Just haven't gotten the 12Volt bus worked out yet. Soon I assure you:thumbs:
 
GT6Steve said:
BBShark said:
Do you know what kind of water pressures and flow rates you are generating?
Click to expand...

Not precisely. It's on a 3 HP well pump thru a 5/8" garden hose at about 40 PSI. I'm still experimenting with the appropriate restrictions in the discharge hoses to control in my HP range. I expect to be able to stall the engine when it's correct but maybe not. We'll see.

Got some work to do now before I can try again.

Ironically, I have a big red mushroom head E-Stop buton to insert into the 12 volt ignition system as well as an RPM activated switch. Just haven't gotten the 12Volt bus worked out yet. Soon I assure you:thumbs:
Click to expand...

:thumbs::surrender::sos:
 
Last edited:
As with every driveshaft, you need to keep misalignment within limits. The vibration destroys almost every bolt in due time.

As for that big red switch killing the ignition.... well I don't think that would suffice. Let say, you are running 7000 rpm and the water pressure/flow falls away because the hose comes off or something like that. Almost instantly the engine will skyrocket to 10000 + rpm. I don't think you would have enough time to kill it...hence I think the electronics are more secure. Of coarse i will have a big red button to press, but it will not be my first line of safety measures.

Steve,

How much torque/hp can it take and at which rpm ?
 
Belgian1979vette said:
As with every driveshaft, you need to keep misalignment within limits. The vibration destroys almost every bolt in due time.

As for that big red switch killing the ignition.... well I don't think that would suffice. Let say, you are running 7000 rpm and the water pressure/flow falls away because the hose comes off or something like that. Almost instantly the engine will skyrocket to 10000 + rpm. I don't think you would have enough time to kill it...hence I think the electronics are more secure. Of coarse i will have a big red button to press, but it will not be my first line of safety measures.

Steve,

How much torque/hp can it take and at which rpm ?
Click to expand...

:eek::thumbs: NO question....still like my BOZO button though....

gotta have a backup....just gotta...
 
You must log in or register to reply here.
Top