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koba
14th May 2008, 15:23
I've been reading and daydreaming and would like to revisit the idea of a bucket dyno.

Someone please tell me why this wont work:

Make a crade for the engine, that bolts to a bigger frame either adjustable or just make a cradle for each engine type.

Add a shaft that can be chain driven from the engines sprocket and attach the other end of the shaft to a big old water pump like (not exactly but just as an idea) this one:
Waterpump Auction (http://www.trademe.co.nz/Business-farming-industry/Industrial/Compressors-pumps/auction-154885844.htm)


Then draw water out of a big barrel into the pump inlet.
from the pump outlet run a pipe back into the water source.
Using lots of water may dampen effects of temp changes in the water.

Have a restiction (valve) in the inflexable line from the pump outlet to the water source that cound be adjusted to "tune" the meter for the appropriate motor.
Once tuned the restriction would remain fixed and then a pressure gauge before the restrictor could be used to determine the torque of the motor at a given rev range. pressure readings taken at different revs (after conditions stabalise) would be taken down, then changes made and another run made asap under as close conditions as possible to make a comparative reading.

Obviously it would only be comparative data and even conditions on different days would influence the results alot so a base run would have to be made each time to account for temp changes ect.

If you were hardout mathsy some conversion factors could probably be devised over time from keeping thorough, accurate records.

As far as I understand it is pretty much how an old style dyno works anyway...

I don't know if that makes sense but I WANT A DYNO DAMMIT!

Seems to me that altho not perfect such a system would be better than an arse dyno for pissing about with buckets and the like, also it wouldn't have to be 2 massive.



All feedback and debate encouraged and I may try to draw a picture.

Skunk
14th May 2008, 15:56
I'm thinking of something driven by the rear wheel for tuning purposes. More useful than remove the engine.

First up though is a bike starter. When I get the time and materials together.

CookMySock
14th May 2008, 16:42
it will be a lot tidier if you can put a sprocket on some electric motor and mount it in the rear axle area. The motor can be used as a generator and then it's quite trivial to use an electrical meter on it, or better still, interface it to some simple A-D converter to make a nice graph of it on your PC. Then you can compare graphs between runs etc and see where your improvements (or other) lie.

edit: you can probably use a legacy PC motherboard joystick controller. It's only 8bit (256 steps) but enough for a pretty graph.

edit: or make one of these http://www.sensorwiki.org/index.php/Building_a_USB_sensor_interface

DB

koba
14th May 2008, 20:43
hmm, good thinking!
would u be able to put enough load on the bucket engine with a reasonably sized electric motor tho?

CookMySock
14th May 2008, 22:22
you might have to rewind it. Will have to have a think about that.

DB

bungbung
15th May 2008, 09:18
Use a series wound DC motor, you'd need to know the efficiency lets say around 70%. You need to dissipate 20Hp peak, which you can split between heat at the motor and a load. 20hp is around 15kW. You'd need some way of getting managing more than 10kw (after generating losses). It's not a continuous load though, maybe heat a drum of water.

CookMySock
15th May 2008, 09:41
what is the reason for the serious-wound DC motor ?

DB

koba
15th May 2008, 10:32
Use a series wound DC motor, you'd need to know the efficiency lets say around 70%. You need to dissipate 20Hp peak, which you can split between heat at the motor and a load. 20hp is around 15kW. You'd need some way of getting managing more than 10kw (after generating losses). It's not a continuous load though, maybe heat a drum of water.

Jeeze Im lost already!
Im still tring to think how an increased torque load at identical RPM would effect the generator. Is that kinda what you talking about bungbung?

F5 Dave
15th May 2008, 10:35
The big problem is where are you going to house this? Not in suburbia for sure, noise police will be around in seconds.

cooneyr
15th May 2008, 10:47
Have a read.

http://pages.quicksilver.net.nz/geoffm/dyno/dyno.htm

Cheers R

bungbung
15th May 2008, 11:54
what is the reason for the serious-wound DC motor ?

DB

It'll need to be pretty serious to cope.

The GL145 motor puts out serious power.

At least it did until Mr. Valve met Mr. Piston

koba
15th May 2008, 12:45
Have a read.

http://pages.quicksilver.net.nz/geoffm/dyno/dyno.htm

Cheers R

Awesome, I got some reading and dreaminig to do....


The big problem is where are you going to house this? Not in suburbia for sure, noise police will be around in seconds.

Fuck the po-lice!
Naa seriously that was one of the reasons I was thinking more along the lines of an engine dyno, inside a garage with very muffled fume extraction.
Timing would also be important. (not 7am sunday morning!)

RantyDave
15th May 2008, 20:54
I had pages of stuff written about making a dyno ... yesterday. I went to post it and discovered the site was dead due to some upgrade thing. Dah! You at the buckets this weekend?

Dave

Skunk
15th May 2008, 20:55
He better be.

Mike748
15th May 2008, 21:09
Have thought about the idea of a Dyno, but it just gets tooooo complicated for me to even attempt.
I considered water pumps but thought if you could get a generator and run that off a couple of rollers driven by the back wheel it would be simpler and space for me is a problem.
I want to be able to run the bike onto the dyno without taking things apart.

CookMySock
15th May 2008, 21:33
I'm coming down for the weekend, unless everything turns to custard. It had better not.. :Oi:

An inertia dyno sounds interesting.. The power is measured by how long it takes the engine to spin up a flywheel. Could get dangerous though, lol.

koba
16th May 2008, 10:36
yeah, sounds harder to make a decent one (to me at least)
it also sound harder to pinpoint the area given changes effect.

koba
16th May 2008, 10:37
I had pages of stuff written about making a dyno ... yesterday. I went to post it and discovered the site was dead due to some upgrade thing. Dah! You at the buckets this weekend?

Dave

I shall be binning it with the best of them!

Str8 Jacket
16th May 2008, 10:46
Dear Mr koba,

Please note that there is NO ROOM in our lounge for this dyno thingamebob that you wish to make. There will be no correspondence entered into. The answer is no!

Luffs ya
:p

Skunk
16th May 2008, 10:48
I've got room in the back yard. And I saw LOTS of room at the Kendogs for all sorts of things.

Trudes
16th May 2008, 11:35
I've got room in the back yard. And I saw LOTS of room at the Kendogs for all sorts of things.

hahaha, you cheeky shit! I'm with Hels, sorry the Inn is full!!
However, a dyno machine in my own garage would be quite handy!!!

Slingshot
16th May 2008, 17:44
Bayden was talking about putting a container at the Slipway...said container could house this Dyno quite nicely me thinks.

Skunk
16th May 2008, 20:17
Bayden was talking about putting a container at the Slipway...said container could house this Dyno quite nicely me thinks.
Don't hold your breath... but that doesn't mean it won't happen.

Slingshot
16th May 2008, 20:23
Don't hold your breath... but that doesn't mean it won't happen.

What comes first, the home built dyno, or somewhere to put it.

I suspect that neither will happen ;)

Skunk
16th May 2008, 20:26
The Dyno of course. Don't be practical now.

Trudes
16th May 2008, 20:47
The Dyno of course. Don't be practical now.

Oiiii, are you coming over tonight? I need a screw!!

Kendog
16th May 2008, 20:52
Oiiii, are you coming over tonight? I need a screw!!

Oh my god.

Skunk
16th May 2008, 20:52
Oiiii, are you coming over tonight? I need a screw!!
Oh, a screw. I see.

Trudes
16th May 2008, 20:52
Oh my god.

Or is it a bolt??

Trudes
16th May 2008, 20:53
Oh, a screw. I see.

No, I've just realised it was a drilling!!!

Skunk
16th May 2008, 21:07
OK. I'll be onto it then.

koba
17th May 2008, 23:05
Jeeze you guys are mad...
A dyno on a trailer would be a silly possibility.

Skunk
18th May 2008, 09:07
A dyno on a trailer would be a silly possibility.
Fucken sense again. Go somewhere else if you're gonna talk sense.

Kickaha
18th May 2008, 15:42
Jeeze you guys are mad...
A dyno on a trailer would be a silly possibility.

Been done before, there's one in Chch like that, then when you want some more room at home you just go and dump it up someone else driveway:lol:

koba
19th May 2008, 10:22
Been done before, there's one in Chch like that, then when you want some more room at home you just go and dump it up someone else driveway:lol:

Yeah, after reading stuff on one of those links I was looking at the guy in Chch who built his own inertia dyno and thinking "that would fit in a trailer nicely".

Trudes
19th May 2008, 10:25
Bring it! We all want to be dynoed!! :)

koba
19th May 2008, 10:34
Bring it! We all want to be dynoed!! :)

If a dyno was actually built (very sketchy if) and if (another sketchy one) a container at the track happened that could be a possible solution to where to house it...
BUT ya really want it at a workshop where developmenat work could be done anyway.

Str8 Jacket
19th May 2008, 10:37
If a dyno was actually built (very sketchy if) and if (another sketchy one) a container at the track happened that could be a possible solution to where to house it...
BUT ya really want it at a workshop where developmenat work could be done anyway.

developmenat - is that some kind of new fangled french word or summat? :p

koba
19th May 2008, 12:43
developmenat - is that some kind of new fangled french word or summat? :p

:p

tenchars

TZ350
24th May 2008, 20:40
Another way to measure HP with a water pump that eliminates heating and other losses is to have the pump free to rotate a few degrees and have a torque arm resting on a load cell, (load cell could just be bathroom scales) or has weights added too it until it just balances the engine torque. Measure the pump shaft RPM and then simple maths using measured torque and RPM gives you HP. Another way is, is instead of a water pump use a disk brake as the load and measure torque and rpm as above. I have seen this done using a ventilated disk on Chrysler Hemi V8's. Everything glowed red hot including the exhaust manifolds and sparks flew out of the disk brake assembly but it all worked and it was simply torque times RPM ie "work-done over time" expressed as HP.

TZ350
24th May 2008, 21:10
Another thought (concept) on a disk brake dyno. It would be possible to put the bike on a race stand, remove the rear wheel and fit the disk brake dyno assembley in its place. A rider could then sit on the bike, start it up and work the controls while an old PC collected the data and gave a detailed print out with graphs etc in real time.

Skunk
24th May 2008, 21:33
I think I'll start with a rolling road with variable load then worry about gathering hp and torque figures. I just want to be able to tune easily.

TygerTung
24th May 2008, 23:13
The free to rotate with a torque arm is how they usually work, it seems, there is an article in an 80's performance bike that I read about it.

TZ350
25th May 2008, 14:03
There is on the internet a dyno software package (about $10 USD) that works like an inertia dyno by using the bike plus riders mass as the load and the change in RPM of the engine to measure the acceleration and works out the HP required to accelerate the bike plus rider. I brought this package and it has nice torque and HP graphs. The hard part was recording the change in RPM. You are meant to use a recorder of some sort, tape, video, anything that can pickup the spark noise and then play it back into a PC through the audio card. This worked OK on my car where the spikes from the ignition pickup were of a uniform size but the bikes ignition signal varied to much with changes in load. Ie the bikes ignition will only put out enough omph for the spark to jump the gap and the omph required varied with acceleration but the car with its distributor etc gave a more consistent signal. Perhaps someone out there can help to develop a means of converting the ignition noise to a consistent amplitude from a single cylinder CDI and recording it into a simple tape recorder, help with this would be much appreciated.

If anyone else is interested I will find the URL for the software.

TZ350
25th May 2008, 21:46
The Road Software Dyno is so simple, you just attach a recording device to the bike. Go for a blat. Download the recorded data to a PC. Analyze data. Fiddle with bike. Go for another blat. Check the recorded changes. Real simple. More blats, more changes more power.

This is a really good looking cheep dyno kit about 75 pounds for the kit. http://www.roadtune.co.uk/index.shtml

This is a really good description of how the in vehicle software Dyno is setup and works.
http://www.microsmith.co.uk/rd/dyno.htm

This URL does not work but it is where I got my software from last year.
http://www.charm.net/~mchaney/homedyno/dynokit.htm

Some general racing info and free software
http://racingdownloads.com/

Another dynokit
jgarman@earthlink.net

CookMySock
26th May 2008, 09:04
To get repeatable results with a road dyno you need to reuse the same piece of road and same rider weight, fuel weight, etc, or you get false "improvements".

I think the dyno could be built into a bike trailer. Ie, the trailer gets used to transport bikes, but has a dyno in it.

Next problem is the 300KG inertia mass weight / rotating drum. This can be resolved by gearing up the drum to a lighter but faster rotating drum. Three times the RPM for the same weight drum is three times the inertia.

DB

TygerTung
26th May 2008, 18:37
Somone down here just built an inertia dyno using a 700kg drum.

CookMySock
26th May 2008, 19:05
Somone down here just built an inertia dyno using a 700kg drum.Itsa good idea. Except it weighs 700kg. Just for the drum. Gear it up I reckon.

DB

koba
27th May 2008, 15:07
From what Ive been reading on that you can only make it go so fast before the forces cause the thing tio come apart :shit:
Dunno how close you would get gearing it up but there would obviously be sa limit that you would want to keep a fair magin away from!

koba
27th May 2008, 15:13
The Road Software Dyno is so simple, you just attach a recording device to the bike. Go for a blat. Download the recorded data to a PC. Analyze data. Fiddle with bike. Go for another blat. Check the recorded changes. Real simple. More blats, more changes more power.

This is a really good looking cheep dyno kit about 75 pounds for the kit. http://www.roadtune.co.uk/index.shtml

This is a really good description of how the in vehicle software Dyno is setup and works.
http://www.microsmith.co.uk/rd/dyno.htm

This URL does not work but it is where I got my software from last year.
http://www.charm.net/~mchaney/homedyno/dynokit.htm

Some general racing info and free software
http://racingdownloads.com/

Another dynokit
jgarman@earthlink.net


Still catching up on all this reading!

Altho the ropad thing may not be perfectly accurate it seemms to be good for the price/complexity of it, certainly must be better that an arse dyno!

koba
27th May 2008, 15:15
I think "Autocar" use a real fancy accelerometer (vbox or Xbox or somthing?) for their acceleration tests and I think that is supposed to be super accurate.

CookMySock
27th May 2008, 15:33
From what Ive been reading on that you can only make it go so fast before the forces cause the thing tio come apart :shit:
Dunno how close you would get gearing it up but there would obviously be sa limit that you would want to keep a fair magin away from!If the geared-up inertia drum bit is much smaller, it will fit in someones balancing machine quite nicely. It would be cool if it could use bike chain-drive stuff for the gear-up bits - cheap and strong. An overrun clutch would be good for safety, as the bike and wheel drum could shutdown real quick and leave the inertia drum to amble down at its' leisure.


Altho the ropad thing may not be perfectly accurate it seemms to be good for the price/complexity of it, certainly must be better that an arse dyno!Agreed, but to be really useful, the dyno needs to be able to tell you "YES! that mod gave you the extra midrange you thought it would" or else its just an expensive ornament.

An eddy current brake is a simple and effective way of slowing everything down after the run, without heating hell out of the bikes' brakes. http://en.wikipedia.org/wiki/Eddy_current_brake

DB

TygerTung
27th May 2008, 22:41
Advantage of a dyno where the bike doesn't move is A: Safety, B: you can hook up gas analysers etc and you can hear the engine and other assorted bonus's

quallman1234
30th May 2008, 22:46
http://www.dsm.org/tools/calchp.htm

This obviously wouldn't be anywhere near accurate enough due to human error in getting off the line etc.

However i still tried it using Koba's times from the clif hanger spirnts and his RG150 worked out to be 21hp (170kg total weight at a estimate! 110 for RG 60 for Him what probabaly is quite off)
But 21hp probabaly isn't too shy of the true value.

koba
30th May 2008, 23:10
http://www.dsm.org/tools/calchp.htm

This obviously wouldn't be anywhere near accurate enough due to human error in getting off the line etc.

However i still tried it using Koba's times from the clif hanger spirnts and his RG150 worked out to be 21hp (170kg total weight at a estimate! 110 for RG 60 for Him what probabaly is quite off)
But 21hp probabaly isn't too shy of the true value.

Again roughly by that the VFR should have had around 51 at the wheel.
That does sound about right BUT it is still a guess as they say...