Simplest DYNO for RC Engines! - Prony Brake Dynamometer!

5. mars. 2021
160 711 Ganger

For this experiment, I'm using the Toyan FS-S100 4 stroke engine.
As I stated in my videos with the twin cylinder, I was interested in making a dynamometer to measure the output power of these little engines. One of the simplest ways to achieve that is to make a Prony Brake dynamometer. Basically, it's a clamp which holds the engine's shaft. The more it's tightened, the more it's been pushed on the scale by the engine's output shaft friction on the wood. This can be a lot of fun because we can test various engines with different fuels with or without mods.
➜Toyan FS-S100 engine:
➜ Other Toyan Engines:
➜Banggood Spring New Arrivals:


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  • Very hardwork dude

    Mani X GamerMani X Gamer13 dager siden
  • Great idea

    Frankie Rzucek JrFrankie Rzucek Jr17 dager siden
  • Es es hermoso Tu arte me haces llorar cada vez que me hablas lo que estás haciendo no puedo comprender tanta maravilla No tengo más que agradecimiento Gracias por todo amor que nos obsequia y locas con ternura jamás volveré a ver al metal como una cosa muerta si no como que me grita para revivir

    Oscar CondeOscar Conde20 dager siden
  • It's not just easier to strap the engine to a electric generator and measure the current (Whatts) and then convert that to HP?

    Lorenzo QñzLorenzo Qñz21 dag siden
  • Can you make one with an rpm sensor?

    TheSabreTheSabre23 dager siden
  • Have you considered using a generator instead? I would imagine you could make a detailed powergraph

    Simon AndreasenSimon Andreasen25 dager siden
  • Somebody: .... Anybody: .... Everybody: .... Me (Every Video): YOU PUT SEX IN MAH EYES !

    Nisemono YarouNisemono Yarou27 dager siden
  • Pretty bad result. Chainsaw engines are give more power having similar size in comparison.

    Alex IvAlex Iv28 dager siden
  • I guess your dynastend is not fully correct. I would advise to using electric generator with some rheostat

    Малик ШамсутдиновМалик Шамсутдинов29 dager siden
  • Hey Johnny are you working on a new video right now? i think i can hear you. hahaha

    kostasrigaskostasrigasMåned siden
  • Gk guna

    D S N GamersD S N GamersMåned siden
  • Could you put supercharger on rotary

    Domba 2109Domba 2109Måned siden
  • stop this madness with imperial units and use metric instead please.

    hypt0nyhypt0nyMåned siden
  • Ik why the mini impeller didn’t make a lot of boost, it needed a diffuser, just make one, and that will increase pressure for the supercharger.

    Ray GunRay GunMåned siden
  • This is not valid. You are measuring dynamic force on the scale as engine rpm varies. That is not a valid indication of the engine's torque because it's affected by the momentum of the engine's rotating mass accelerating/decelerating. (There are really two types of dynos: one requires engine rpm to be steady, I've usually heard these referred to as "brake" dynos. Each rpm level is individually evaluated. The other is a rolling dyno, where the engine is accelerated at full throttle throughout its range and the rate of change of the roller's speed is used to extrapolate torque and therefore horsepower, these are usually called "chassis dynos". The first type is considered more accurate; the second type is much easier to use and what you always see in consumer dyno tests. In this case you have multiple variables contributing to one value. Your results are unfortunately not accurate as a result, and very likely wildly inaccurate.)

    GlennC777GlennC777Måned siden
  • I think he is fron germany, so it is not possibile for him to buy better fuel, because the good Nitro Fuel got Banned in the EU this year :-(((

    Andy PrivatAndy PrivatMåned siden
  • Thats isnt safe for ur engine if u stall until the engine stop

    Jack GamesJack GamesMåned siden
  • What's that he is using? That rotating thingy? Sorry I'm still to this stuff

    Sure LuckSure LuckMåned siden
  • Yep we gotta see more testing. Plus the testing on your engine upgrades.

    Google UserGoogle UserMåned siden
  • I don't see why he doesn't sell some of his inventions / products he makes. He can make a fortune..

    FLYHIGH McCoyFLYHIGH McCoyMåned siden
  • As a Swede, you are always on the wrong side when discussing car power output. We use Horsepower and Newton Meters :D

    James BananaJames BananaMåned siden
  • Good day . We invented my Lord boss and I a super revolutionary engine for any type of fuel, including hydrogen for 0 emissions, obtaining much more performance than any other current engine and greater than batteries or fuel cells that are used in combination with electric motors, It has a tubular format with one or more stations and a novel thermodynamic cycle, with only two main moving parts, a power / weight ratio greater than 10 Hp / Kilo in its basic form, its thermal efficiency is greater than 75% three times more than the Current engines, everything can be manufactured in aluminum (except the main shaft and screws), it does not use liquid coolant, it uses very little lubricant, it can be extrapolated to any power without losing characteristics, it is patented in Brazil and also in international PCT. Very easy to manufacture 100% with current basic technology, all its moving parts 100% mounted on commercial bearings, the useful life is greater than 30,000 hours (> 30 years) with very low maintenance and more than 50 additional advantages ... ... As an example: drones of any size can be made with subsonic and supersonic high speed vertical take-off (goodbye to helicopters, traditional airplanes and airport runways), it does not use a turbine or axial compressor, it is not ramjet nor is it scramjet for M> 1 and more, it has a frontal area of ​​20 cm2 / Ton. of thrust and more than 100 kilos of thrust / kilo motor, it is similar to a rocket motor and 100% safe, with more than 40 thousand kilometers of autonomy in all types of drones at a cost many times less. If you are interested and you are a medium or large company, you can produce with very little investment in a few months under a license (This would only be charged per engine produced) for engines of any type and size, contact us, you will not regret it, by email: elmontecarmelo1 @ gmail .com . It is not a joke, I repeat it is not a joke, we are serious and responsible people, we welcome constructive comments. YOU WILL NOT SEE THIS ENGINE IN ANY BOOK OR ANY OTHER SITE.

    Manuel ExpositoManuel ExpositoMåned siden
  • This setup seems more suited for a static load like measuring the force it takes to break something. Im guessing real dynos have rollera for a reason so you can see how the engine behaves at different rpms

    Raj GillRaj GillMåned siden
  • When is this guy gonna make his own rc engine!?

    ethan gregoryethan gregoryMåned siden
  • OZ ? Pounds ? Feets ? You know there is an international units system in place ? That’s not imperial units for sure. Start using the international mode instead of your local one :)

    ffx fanffx fanMåned siden
  • Your bandsaw shouldn't be struggling like that to cut MDF.

    Fuzzy JohnsonFuzzy JohnsonMåned siden
  • ?? So it basically makes no power....or maybe one mouse power..

    weldin theworldweldin theworldMåned siden
  • I'd expect any manufacturer's specs to be exaggerated, but 1/5 seems excessive. The fuel could make a difference, but there may be some measurement error there. Given the small scale, small errors can amount to huge variability in accuracy. Excellent concept, just a bit of refinement may be necessary 👍

    TiporariTiporariMåned siden
  • did... did you just tap MDF? Am I the only one that saw that?

    infotroninfotronMåned siden
  • Wouldn't make it more sense to measure the maximum stable Power/torque at a given RPM?

    KommanderKommanderMåned siden
  • Instead of trying to measure crankshaft torque directly, you could instead measure the reaction torque against the engine itself (Newton's 3rd Law). If you mounted the engine in a rotating frame, with the frame's axis of rotation inline with the crankshaft, and then had a moment arm mounted to that frame, the moment arm could apply torque to your scale. That would let you measure engine torque in real time without have to stall the engine since the crankshaft would still be free to spin. Of course you would still need to load the crank somehow so you could produce a significant amount of power.

    Dane BeckDane BeckMåned siden
  • Always a good day when when a of yours video is out. Awesome work as always, keep it up 💪

    Grayson BennettGrayson BennettMåned siden
    • Thanks for the comment!

      JohnnyQ90JohnnyQ90Måned siden
  • Greetings my friend I'd Really like to know if I gave you dimensions four small RC parts aluminum possibly would you consider resale? Because I'm blowing away of your skills and I never missed the video you always upload and always share many of my friends follow you now I made my own custom parts for years but wish I had the machines. Please let me know since I'm dead serious.. 👍👍 - Godspeed my RC friends -

  • Now THAT is a nice contraption. Real data from real measurements. Kudos! PS: Power measurement and calculations are part of my profession. Here's a few tips: What you were measuring now was peak torque, and peak torque is always WELL below peak HP. Second thing that went wrong, is that with full throttle, if you bog down the engine, such a simple carb will most definitely not hold mixture, so your actually measured value will not represent what the engine is capable of. Richen up your HS needle a bit and I am pretty sure you will see higher torque values right before stalling. Reason is, dropping RPM reduces intake vacuum, and that reduces fuel draw, and your mixture will lean out because that throat diameter is designed for 10+K, and you are running only 6K. Now, your peak HP will be around 10, maybe 11 K So if you want to know your peak HP, set the brake for around 10K RPM, then peak the needle and if necessary readjust the brake to maintain around 10K. Now try to get torque readings in steps of 200 RPM between 10 and 11 K, and I am pretty confident that you will see higher HP numbers. Realistically, I do not expect 0,5 hp, but 0,4 should definitely be within the range of what is possible. My own 5 cc fourstroke runs on gasoline (less power than Methanol) and manages about 0,3 HP @ 9,5K On methanol, 0,35~0,4 should be absolutely possible.

    rigididiotrigididiotMåned siden
  • That is very simple very genius design. congratulations!

    DaveFromColoradoDaveFromColoradoMåned siden
  • @JohnnyQ90 Did you do the same valve thing on this engin... i know for sure, the valves dont close properly on these engines... I had to mod mine to make the valves close properly...?

    Andre BoilyAndre BoilyMåned siden
    • Yes, same procedure here, but wrong fuel. I used 16% nitro airplane fuel, while I should have used 25% nitro for cars.

      JohnnyQ90JohnnyQ90Måned siden
  • You'd have to be a real dick to give a thumbs down on this channel. . This guys work is at a crazy high level.

    mike smike sMåned siden
  • You may want to change your center shaft to a larger diamater. This will decrease sensitivity to clamping and increase surface area allowing for more mental volume to absorb heat a little better. The prony brakes I have used typically have a hollow cavity inside the metal part to allow for adding watter to help with cooling.

    Steven FirstSteven FirstMåned siden
  • Very cool! Can't wait to see more engines get tested 🙂

    TheBLC94TheBLC94Måned siden
  • Wow no intro or nothing it’s just straight into action, how good.

    Joshua MitchJoshua MitchMåned siden
  • Dude sorry just how did you calculate the hp . I multiplied the force and dis Then the turque and rpm but i didnt reach the number of 0.1 hp

    Erfan VatandoustErfan VatandoustMåned siden
  • So if you were measuring in metric units would you have used metal instead of wood? 😜

    AgentU1AgentU1Måned siden
    • Sure

      MadDog95MadDog95Måned siden
  • Nice very smart

    Calvin GrahamCalvin GrahamMåned siden
  • For testing the torque, would it not make more sense to use a bearing so testing is a little more consistent?

    XlaxsauceXlaxsauceMåned siden
  • Wow,VERY interesting and unique idea here!!! Thanks for posting this one JohnnyQ90!!!

    menom7menom7Måned siden
  • For anyone who is wondering 0.5 feet is 6 inches.

    harbend05harbend05Måned siden
    • Or 1/4 of a cubit......or 8 Hammer Units if you like Steam games...

      Bite My KrankBite My KrankMåned siden
  • Interesting! Works very well for a proof of concept. I think if you were looking to do an upgrade at any point, a road bike brake disk and caliper would make a more robust and sensitive system. Also, you couldn't need to get so close to the rotating assembly.

    RocketplaneRocketplaneMåned siden
  • Hi Johnny, may i request something please. Can we have a top 10 video of your favourate engines?

    DiyEcoProjectsDiyEcoProjectsMåned siden
  • awesomeeeeeeeeeee

    Sachio Isaiah OtsukaSachio Isaiah OtsukaMåned siden
  • Have you seen Warped Perceptions supercharged Toyan motor? That thing sounds disgusting (In a good way) lol. I know you can do better work!

    Vault ManVault ManMåned siden
  • I think and electric motor with variable resistance would be a much easier and more accurate way to do this. Because you are only measuring such small output power it should actually be quite easy.

    Ryan GreenRyan GreenMåned siden
  • use a remote servo to tighten the wing nut 😎👍

    sesssessMåned siden
  • Prony brake!??

    Edivone LopesEdivone LopesMåned siden
  • I disagree ! Good to see the difference with different nitro % 😊

    SilverlyxSilverlyxMåned siden
  • To know torque and power, use an electric motor as generator, ampmeter, voltmeter, and little maths :D

    aerisaerisMåned siden
  • I hope you Dyno the Turbocharged twin cylinder next!! awesome Video

    Tadashi Ja lol eyTadashi Ja lol eyMåned siden
  • You won‘t come close to the manufacturers power rating I guess. Even a really high quality, japanese made OS airplane four stroke engine (OS FSa-56) has a worse power to displacement ratio and they are really powerful and much higher reving. The chinese make cool stuff but they like to print massively exaggerated numbers on their stuff. I‘d say you won‘t get more than 0.25hp out of this engine.

    Christian's Projects - CG ManufakturChristian's Projects - CG ManufakturMåned siden
  • εισαι φοβεροσ φιλε μου!

    ripley arvripley arvMåned siden
  • Have a look at an ardyno board @twostrokestuffing, DIY option for a hobby dyno. Works as an inertia dyno so very simple to setup.

    Robert DoddRobert DoddMåned siden
  • Do you think using 16% instead of 20-25% nitro fuel could result in achieving only 1/5 of rated output? I seriously doubt that. To be honest I never did see a performance difference between 16 and 20% in my engines. Maybe the methodology is off, how much does the arm weigh? I would test it again on a much shorter arm to see if it influences result.

    MasterBataMasterBataMåned siden
  • 10/10=bravou👍😎💖✔

    Khalid DaliKhalid DaliMåned siden
  • Hi, aweomse videos as usual, if i can give an advice: Don't use electronic scale, delay between actual mesure and display can be very different, this will lead to false measure and calculation moreover with small numbers where it makes HUGE differences (0.1 or 0.2 over 3 is already much diff) . Try to find a mecanic scale, you will notice the diff :) . Keep doing great stuff !!!

    Christophe LopesChristophe LopesMåned siden
  • Απλα δεν υπάρχεις!Οτι και να πω ειναι λιγο!Τελεια δουλειά!!!

    tasos.strtasos.strMåned siden
  • P(hp)=1,36*((Nm*rpm)/9550)

    jakuzjelczajakuzjelczaMåned siden
  • Nice concept, but i'm not sure you'll ever get results you can trust from that setup. You're going to need to log the force and speed at exactly the same time or the figures are fairly meaningless. a fairly simple arduino based rig would do the job. and could very easily feed te data directly into a spreadsheet to draw a graph and do the appropriate calculations autoatically. Although it wouldn't be a 5minute project, it's not exactly beyond your skills to get this up and running, and having reliable data would be invaluable in later projects.

    Leon KiddellLeon KiddellMåned siden
  • try making a W16.4 engine

    Vasiliu MateiVasiliu MateiMåned siden
  • That measure isn‘t correct It’s better you have an electric generator and a potentiometer So you can measure Voltage and Amps P = U • I It is the simplest way

    Tom G SeTom G SeMåned siden
  • I would suggest making a small disc brake setup to load the engine with and mount the cable or servo actuated brake on the lever arm to push on the scale. You'll be able to load the engine without directly touching the arm and affecting the measurements. Also it'll involve some cool machining and fabrication.

    huzudrahuzudraMåned siden
  • great idea

    SneakyGunzSneakyGunzMåned siden
  • Your tester isn't so precise.

    master Bryanmaster BryanMåned siden
  • Very interesting! Will the diameter of the axle being clamped affect the torque?

    Ivar HoffIvar HoffMåned siden
  • Oooh time to test V4 on iy

    Odd GamingOdd GamingMåned siden
  • Check if that mdf has constant friction/temperature. Seems like it could adjust more gracefully. Maybe larger diameter shaft and something else for braking material between metal/mdf torque arm?

    Ilkka SorsaIlkka SorsaMåned siden
  • Suggestion: Instead of using wing nuts and possibly adding weight to the scale with your fingers touching the wing nut. You could mount a high torque servo in some fashion to the brake and then use use a simple dial adjustment to clamp down on the brake for real precise braking and measurement. Just an idea I came up with watching it.

    D KD KMåned siden
  • Hi Johnny, for a coorect mesure of the power you need to make it every time at full trottle, and adjusting the rpm by clamping the brake, otherwise you do not measure the maximum torque at the various rpm

    cobalto95cobalto95Måned siden
  • 152.4 same caliber as KV2. I bet u play wot

    Zues_Of_JuiceZues_Of_JuiceMåned siden
  • #askJQ90 Show us your engine and rc collection in the next video

    Pramod .g.kPramod .g.kMåned siden
  • 0:07 Can you record a thermal image of this please ? How hot are that blade like thing and the cylinder ?

  • How could you test electric to find out best rpm point for tire gear combination ✌️ love to see something like that 💯⚡

    M JM JMåned siden
  • Keep going!

    Day WalkerDay WalkerMåned siden
  • Engine Po for v4 Engine go pro

    LÔC JMC NguyễnLÔC JMC NguyễnMåned siden
  • Can you please put a turbo on a mini 13b, I want to see you work that

    Antonio LawsonAntonio LawsonMåned siden
  • If you're in the EU, buying 20% will be difficult/impossible since the EU's new regulations regarding model engine fuels doesn't allow the sale of any model engine fuel above 16% without a licence (for both customer and seller). I expect most sellers won't stock up on >20% anymore :-(

    2stroke4me2stroke4meMåned siden
  • Your math is off. Hp= tq x rpm / 5252 Using the force measured at 3:57 - 3oz @ 1/2 ft = 6 oz/ft or .375 lb/ft .375 x 6600 / 5252= .471 hp. Great work and thank you for the quality content.

    Jonathan WJonathan WMåned siden
  • Does this man have an engineering degree 🤔

    Mickey BeahlMickey BeahlMåned siden
  • How do you concentrate with those damn dogs barking in every video?

    lakerdude42lakerdude42Måned siden
  • 👍👍💖👍👍

    Tamas EduardTamas EduardMåned siden
  • Can maybe try to compare the power of those cool fancy 4 strokes vs 2 stroke nitro engines from RCs, could be cool because they spin at much higher rpms than those 4 strokes

    itay ben-yosefitay ben-yosefMåned siden
  • I dont think 25% will quadruple the power. But worth a shot.

    Nathaniel MathiesNathaniel MathiesMåned siden
  • SmallEngineMechanic anyone?

    AcerJJJAcerJJJMåned siden
  • 5-10% more nitro content won't make any difference

    Edwin-F-104Edwin-F-104Måned siden
  • Bump that nitro fuel up to the Traxxas 33% nitro and see what it puts out then! I run the 33% in my 3.3 Revo and that dude will flat MOVE now... Its AWD with a 2 speed gearbox, long travel suspension arms, steel gears in the transmission, a 4 shoe clutch, dual disc brakes, all the plastic mounts have been replaced with carbon fiber, higher capacity fuel tank, primer bulb in the fuel line, dual high speed high/high torque steering servos, reverse delete, LiPo receiver battery, onboard volt meter, RPM control arms and spindles, and, I locked the rear diff so it will pull wheelies better. When I say better, I mean that the diff action would make it kind of bounce if the tires had any slip. All my buddies want to drive it, but it is stupid fast, and they would just crash it.

    Robert SchemoniaRobert SchemoniaMåned siden
  • That’s a neat low-tech method, but instead I’d have made a simple (arduino) USB/serial datalogger, using a photo-interrupter and a load-cell ADC circuit. Should get me a whole torque curve from it. Planning do do something similar myself for a BLDC, though my motor’s torque is enough to send it into orbit, so I’ll have it vertically mounted with rotationally symmetric spars connecting the brake housing to the motor housing. Using an identical motor as an EM brake, because I have two of them anyhow, and it lets me easily dump all the heat into a water tank.

    James BarclayJames BarclayMåned siden
  • Just use big enough rc car engine and brake with the remote

    Philippe Richer PepinPhilippe Richer PepinMåned siden
  • You should couple the output of the engine to a dc motor and connect the output to a variable load bank..

    MrTurboturbineMrTurboturbineMåned siden
  • Try making mini disc brakes with calipers, I think it's a good idea!!

    Jivitesh PandabJivitesh PandabMåned siden
  • My Little Prony: Friction is Magic

    RickBaconsAdventuresRickBaconsAdventuresMåned siden
  • Can you expect the engine to show 0.5hp just by increasing nitro mix levels? I'm not convinced based on 16%nitro fuel giving 0.1hp you will get 0.5hp from 20% nitro mix. Love your videos though and looking forward to you proving me wrong.

    JJMåned siden
  • Did you apply the conversion constant? Horsepower isn’t simply pound-force x rpm. You have to divide by 5252 and I didn’t see you mention this. Also you are measuring torque force at 0.5 feet, so this also needs to be factored in. You might have done this but I didn’t see any mention of it.

    Lozzie74Lozzie74Måned siden
  • A significant portion of the engine's output may be lost to heat at the wood/metal interface. A lot of people have suggested an electric motor as a load, I think it's a good idea too. The trick will be calibrating it. Possible calibration procedure: - attach a pulley to the motor - wrap a string around it several times - tie a known mass to the string - drop the mass off the table The falling mass will provide a constant known torque. (mass * pulley radius * acceleration of gravity) If you record the drop with a camera, and have a meter stick behind the mass, you can measure the acceleration and velocity of the system. The input energy can be easily calculated using the distance the hanging mass fell. There's a few more math steps after that, but nothing too crazy.

    Ed CramerEd CramerMåned siden