Homebuilt engine dyno?

[jaguarking11]

Well inspired by another thread I want to buy a small engine to tinker with just for the fun of it. But having a running stationary engine is fun but also frustrating when you dont know the exact efects of the changes and experiments made do to the engine. So I figured I could try to fabricate a homebuilt dyno.

I know dynos are usualy rpm meters that measure rpm on the output versus aceleration with a heavy weight being spun in theory.

Any ideas and or guides I could take a look at?

[cobalt6700]

i have a old strimer engine you can buy off me......

[jaguarking11]

i have a old strimer engine you can buy off me......

Got any pics? Whats the price of it shiped? And what are the specifications? How old and whats the fuel type?

[BigBen2k]

The weights replicate a load; that's the key part.

Knowing some torque parameters will tie in everything together. Look at existing vehicules, figure out their curb weight, and with known (published) torque figures, you ought to be able to figure out which set of weights to use.

You ought to make it adjustable, but you still have to be safe; I'd wrap the weight assembly in a heavy cage.

Other than than, all you really need is a sensor for the output rpm, on top of the engine monitoring that you want to do.

Oh yeah, you'll have to implement your own cooling solution too; a big rad with an unusually large fan; a blower would be perfect here.

[jaguarking11]

The weights replicate a load; that's the key part.

Knowing some torque parameters will tie in everything together. Look at existing vehicules, figure out their curb weight, and with known (published) torque figures, you ought to be able to figure out which set of weights to use.

You ought to make it adjustable, but you still have to be safe; I'd wrap the weight assembly in a heavy cage.

Other than than, all you really need is a sensor for the output rpm, on top of the engine monitoring that you want to do.

Oh yeah, you'll have to implement your own cooling solution too; a big rad with an unusually large fan; a blower would be perfect here.

Thanks for the input bb2k.

I posted the same thing as here on bit and someone posted this.
http://www.eng-tips.com/viewthread.cfm?qid=84432

It looks like im going to look into a turbine and possibly having it spin in oil.

Maybe for now im going to get a small engine to experiment with, im looking at sears gass powered weedwackers.

[BigBen2k]

I like the oil idea; it would replicate the drag/friction, to some extent.

The weight alone replicates the load of the weight of the vehicule, but none of the drag.

I would imagine that this oil could warm up pretty nicely; I'd look out for that.

Sounds like a fun project!

[jaguarking11]

I like the oil idea; it would replicate the drag/friction, to some extent.

The weight alone replicates the load of the weight of the vehicule, but none of the drag.

I would imagine that this oil could warm up pretty nicely; I'd look out for that.

Sounds like a fun project!

Well I could run the oil through a hearercore with a cuple of powerfull fans on it.

It does sound like a fun project but I hope my budget can withstand the experiments.

I also have a form of forced induction thats electronicaly controlled in the works. But thats hush hush.

[cobalt6700]

jagking...... check your PM

[jaguarking11]

pmd ya back.

[jaguarking11]

Thanks for the help guys. I have been doing reaserch and for the moment such a project for me needs two thinks that i dont have. 1st thing is a larger budget than what I am prepared for and second oodles of time for fabrication.

looks like this is going to be on hold for quite a long time. :-(

[Pug]

Actually, DIY dyno (http://www.google.co.uk/search?hl=en&q=diy+dyno&btnG=Google+Search&meta=) got some good hits in Google.

I came up with what looks to be a couple of sites by the same guy who built his own over here at DIY Automotive Dynamometers! (http://www.dynamometer.fsnet.co.uk/diy-dynamometer.htm) and DynoPower Dynamometer Systems - DIY Dyno or Dynamometer (http://freespace.virgin.net/dyno.power/) (looks like he started a store for a while).
A solid steel drum made to our specifications from our drawing, which is of a known rotational inertia, is used. This allows our DynoPower (c) software to calculate the power, using pure maths, at any given road (drum) speed. And by hooking up to the motors ignition system as well to monitor the real time rpm, we can produce accurate power & torque curves from any vehicle. These are then corrected to SAE J-1349 / DIN 70020 / ISO 1585 or EEC 80.1269 standards and then stored on the computer for future use. Because all of this data is accurately calculated, no initial calibration, or re-calibration is ever required, and the figures that are produced can only ever be absolutely correct. This means that any tests conducted on different DynoPower dynamometers in different parts of the world or country can be compared directly to each other no matter who built it or where it is located. In addition the run data can be stored on a floppy disk for backup, and/or given to the customer for him to keep. It can be added to any Dynopower dynamometer computer system at any facility at a later date if needed. This data can also be viewed using our demo & viewer software, which can be downloaded from this site free!
...and a 3rd from NZ - DIY-dyno (http://pages.quicksilver.net.nz/geoffm/dyno/DIY_dyno.html)

Some good resources linked off there too. :thumb:

[jaguarking11]

Actually, DIY dyno (http://www.google.co.uk/search?hl=en&q=diy+dyno&btnG=Google+Search&meta=) got some good hits in Google.

I came up with what looks to be a couple of sites by the same guy who built his own over here at DIY Automotive Dynamometers! (http://www.dynamometer.fsnet.co.uk/diy-dynamometer.htm) and DynoPower Dynamometer Systems - DIY Dyno or Dynamometer (http://freespace.virgin.net/dyno.power/) (looks like he started a store for a while).

...and a 3rd from NZ - DIY-dyno (http://pages.quicksilver.net.nz/geoffm/dyno/DIY_dyno.html)

Some good resources linked off there too. :thumb:

Thanks pug. Your the master.

[Pug]

Heh, you're welcome dude. All credit to Google tho'. ^_^

Hope you manage it someday, could earn you a few bucks by the look of it. Look for a Krypton Tuner* on eBay too, if you ever choose it as a career path. :thumb:

*typical... can't find a webby for 'em. :rolleyes:
It's an engine diagnostic centre, fwiw.

[Knipex]

Today I heard about a woman who was selling a complete setup. Garage lift, dyno, corner weight setup, electronic tracking setup, welder, pipe bender (for exhausts), brake pipe set up, various bits and pieces including a full set of tools.

Her husband just walked out about 6 months back and she finally got the legal bits sorted enough that she can sell stuff and wants to affload all his gear fast for cash. (he used to set up rally cars).

I called her as soon as I heard about it and she still had all the gear and was willing to sell seriously cheap. Only condition was first to arrive with cash and it had to be cash got it and her prefference was to sell it all together.

I rang around and though begging and borrowing managed to scrape a coupel of grand together and called to her place after work. Nothing left NOTHING. She sold the entire lot for 5K to some geezer in a van. He tool the small stuff with him but the larger items were still there.

The lift alone was worth 10K. Its a hydraulic sizors unit that when down slides completely into the floor taking up no space and when raised has a seperate lift that can lift the car off the wheels...

Also included was a convertor to change single phase to 3 phase (lift and compressor were 2 phase) and a complete set of pneumatic sanders and die grinders as well as a quality paint gun and a decent primer gun.

She gave me the guys number in case he was wiling to part with any of it so I rang him. The guy is in the trade and sells garage equipment for a living and is looking for top money for all the gear. He wanted 4.5K for the compressor, guns and convertor alone...:-(

She knows she has been screwed but does not care just wants the stuff gone..:duh:

[jaguarking11]

Today I heard about a woman who was selling a complete setup. Garage lift, dyno, corner weight setup, electronic tracking setup, welder, pipe bender (for exhausts), brake pipe set up, various bits and pieces including a full set of tools.

Her husband just walked out about 6 months back and she finally got the legal bits sorted enough that she can sell stuff and wants to affload all his gear fast for cash. (he used to set up rally cars).

I called her as soon as I heard about it and she still had all the gear and was willing to sell seriously cheap. Only condition was first to arrive with cash and it had to be cash got it and her prefference was to sell it all together.

I rang around and though begging and borrowing managed to scrape a coupel of grand together and called to her place after work. Nothing left NOTHING. She sold the entire lot for 5K to some geezer in a van. He tool the small stuff with him but the larger items were still there.

The lift alone was worth 10K. Its a hydraulic sizors unit that when down slides completely into the floor taking up no space and when raised has a seperate lift that can lift the car off the wheels...

Also included was a convertor to change single phase to 3 phase (lift and compressor were 2 phase) and a complete set of pneumatic sanders and die grinders as well as a quality paint gun and a decent primer gun.

She gave me the guys number in case he was wiling to part with any of it so I rang him. The guy is in the trade and sells garage equipment for a living and is looking for top money for all the gear. He wanted 4.5K for the compressor, guns and convertor alone...:-(

She knows she has been screwed but does not care just wants the stuff gone..:duh:

That sux. I hate when a realy good deal gets taken from under me. Sickening.

I would have loved that equipment. As im shure you would have too.....

Ah well something will come up.

[jaguarking11]

Heh, you're welcome dude. All credit to Google tho'. ^_^

Hope you manage it someday, could earn you a few bucks by the look of it. Look for a Krypton Tuner* on eBay too, if you ever choose it as a career path. :thumb:

*typical... can't find a webby for 'em. :rolleyes:
It's an engine diagnostic centre, fwiw.

Thanks I hope I manage getting a home built dyno one day too. But as far as it being a carrer path, Im too crazy about hp and would probly kill myself testing cars. So I think this is going to be just a hobby. I want to build a car one day. My carrer is telecomunications, mainly focusing on networks. I love doing that too.