Engine dyno

[66brm]

[esde]

[TomSimon]

I have a friend who made his own engine stand type dynomometer, then started making them for sale a couple years ago.

The basis is pretty simple. It has a simple steel disc, connected to the crankshaft, spinning at the same rpm as the engine. The disc is in water, inside an enclosure. The enclosure is supported in bearings, allowed to pivot or spin a few degrees, on the same axis as the crankshaft and disc. The disc spinning in water, inside the enclosure, makes the bearing mounted enclosure want to also spin. Essentially making the assembly a fluid coupler, just like an automatic transmission's torque converted. The enclosure has a torque arm attached to it, which rests against a stop, that keep the enclosure from rotating. Between the torque arm and the stop, is a load cell. You could buy a load cell that reads voltage, or build one like my friend did, that reads PSI. His uses a wheel brake cylinder, of known diameter, filled with oil, and ta mechanical PSI gage. X pressure in PSI equates to load, multiplied by the length (in feet) of the torque arm.
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2-time NASA Pro Racing Champion, Bonneville 130 Club and 150 Club Memeber, BRS Pro Gas racer

[Juanito84]

If the disk churns enough water to slow down the engine at full torque you could adjust torque by the amount of water inside the thing.

I still think my hydraulic idea would work. There are plenty of tractor part stores that have all the hydraulic lines and valves and such that can handle even more pressure than needed. Yes a leak would be bad. It could inject hot oil right into your skin. Then it would be a quick amputation or death. So lots of shielding would be a good idea.

I'd take an old transaxle that's geared high enough in fourth so the axle shafts don't reach much higher than 1,000RPM. I'd lock the differential and leave it locked in fourth gear. I'd have two custom splined shafts made to bolt onto the IRS flanges. I'd put on 40gpm 2,000psi pumps in pairs, one on each shaft. You'd need a pair for every 100 hp, so 200hp = 2 pairs or 4 pumps. Then I'd make two braces that are bolted to opposite ends of the transmission. Then I'd brace or chain the pumps to both braces so that there would be no lateral force on the transmission flange bearings. I'd plumb all the pumps together into one large pipe keeping in mind each pump pumps up to 40gpm. Then I'd plumb that into some valves, one of them being a needle valve for fine control. Some over-pressure safety valves would also be a good idea. A large pressure gauge before the valves would be my torque gauge. I'd calculate the torque and re-mark it with lbs-ft. Then I'd plumb from the valves into one large Lupe again and then into some sort of cooler. Seeing how there aren't many radiators that can remove 150kW of heat at 160gpm it might be easier to plumb this low pressure side into several smaller copper pipes and fit them into a tub where I could run lots of cold water over them. From there these would be plumbed into a holding tank that would in turn be plumbed to the pump inlets. A flow meter on one of the pumps could be used to indicate RPM although a regular tachometer would do just fine too. Hp would be calculated from torque and RPM.

I'm sure such a dyno would be very precise and easy to control.
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If a water cooled engine cools its water with air, isn't it just an overcomplicated air cooled engine?

[mcmscott]

http://www.stuskadyno.com/XS111.html

Its really easy
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[Juanito84]

[Brian_e]

I just saw these
http://www.amazon.com/AEM-30-4855-Dyno-Shaft-On-Vehicle-Dynamometer/dp/B007ZGDX4M

Not sure if it would work, but still kinda neat, and relatively inexpensive.
You could mount one inside a cut down transaxle case. I would imagine you would still need a way to load engine.
On an engine stand in the garage, I think this would just be a data collection device.

Maybe build and adapter and bolt it to a CV flange with a shorter axle shaft?

Might be worth looking into?
Brian

[Juanito84]

[Art Thraen]

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[Art Thraen]

[Dale M.]

Water brake?

Dale
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“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
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All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[Jake Raby]

Just watch for an old Go Power or Stuska 400 to pop up. I bought my first Stuska for 1200 bucks, complete.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[Dale M.]

[Jake Raby]

Yes, Depac makes them. They work very well.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[craigman]

[Juanito84]

Here's another (dumb) idea of mine. A lot of smart phones have accelometer sensors built into them. You can download apps that show you what the accelometers are reading. If you fix your phone to your dash and run the app you'll see one of the numbers changing with acceleration and braking. The more you can get it to move the more your vehicle is accelerating (or decelerating).
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If a water cooled engine cools its water with air, isn't it just an overcomplicated air cooled engine?

[Brian_e]

[nsracing]

I got a very old Go-Power... good to 800 HP. have not had time to build the rack for it. I would love to get it going sometime.

[Dale M.]

[nsracing]

Mine will be similar to that but have someone already donated 10" I-beams so will use that.

Gotta have the water pump system w/ huge reservoir for the water collection.