Engine tuning/ bike build
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Its been a while, i just felt like popping in here again and updating everyone, if anyones even interested in my original project anymore, but yeah my cylinder boost porting is still at a standstill. Started school again and dont have the proper stuff to get everything done with that currently but im still planning on doing it so dont worry, with dyno numbers.
However ive been doing some other things in the garage, when one projects gets put to the side u need to come up with something else to do, so im currently in the middle of building my own homemade intertia dyno.
Might not look like much, the base of it is an old electrical engine i picked up for free from an electrical engine workshop mechanic place, the rotor might be a little small and light, but it should do fine with 1st gear pulls and seeing as i dont think anything over 30hp will get dynoed on it everything should be fine. Will it give exact numbers? Probably not, more like ballpark numbers, u cant really expect to get numbers youd get on a namebrand dyno from this thing.
But it will work as a great tuning help, actually being able to visulize if that change you made actually had a positive or negative impact on your engine in the format of an easy to read graph instead of 0-60mph timed runs.Coupled together with this i managed to pick up the discontinoued ArDyno arduino pcb shield that Alex from the twostroke stuffing channel on youtube once made. (great guy and great channel that i recommend every bike interested person in this forum to check out)
Im using a crankshaft positioning sensor to monitor the rpms of the rotor
I also while scrolling aliexpress came across some vforce 3 reed valves for around 10 pounds for the honda cr125, so i picked one up since ive heard that the cr125 reeds fit the Dtr engine block.
Looked and felt good for being a replica from aliexpressI had to do some slight surgery to the inlet manifold since these reeds dont use the same style of stuffer that the dtr reeds do
Also hade to take the dremel to the vforce reeds, the actual reed part fit into the engine no problem but the bolt holes didnt line up, so i had to basically open them up so i could fit bolts through everything.
But its all working good and i dont think its pulling any air through my dremel modifications, can i tell a big difference in how the bike handles? Not really but that might also be because i dont ride it too much, would i be disappointed if i paid the 120 pounds for a real pair? Yes, but since these were a fraction of that im happy with itIm planning on designing everything i need in cad and getting it 3d printed so this wont be as much of a hodge podge as it is currently.
Last little project ive been working on is putting together another expansion chamber but for my scooter instead, its my daily commuter since i dont have my license to ride the dtr yet, its coming together quite good, its all gonna be painted black before im done so dont worry about the rust
Sorry for such a long post that maybe shouldnt be on this forum tbh, hope someone takes the time to read it and finds it interesting, god i wish i could write this much at school
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https://a.aliexpress.com/_mLIIXu7
These were the ones i got, but u will have to do some modification to the mounting holes which y somewhat can see in the pictures i posted above just so u know, and u will have to cut off the original reed stuffers from the manifold
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Hi again everyone, a little update on my dyno project i have going on, im thinking of maybe creating a another thread in the Off Topic section of more in depth instructions and how i did everything if there is demand for it, otherwise everything like anything in the world now adays can be found on youtube
Yesterday i got to building the front wheel "holder" where u slot the front wheel into so the whole bike doesnt move forward, used as many screws as possible and it seems relitivly bomb proof, the last thing i would want is to build a bike launcher that would shoot my bike off into my workshop and for all the gasoline to pour out, ignite, and then the whole garage would be ash, so keeping the bike steady and sturdy intop of both the dyno and my wooden pallets is priority number one
Oh yeah im also building everything ontop of wooden pallets, my first instinct was to weld a frame up from some square metal but i quickly realized that the price would skyrocket that way and me only being 17 with a very limited budget had to grab what i already had available to me, and it was these four wooden pallets, so far they work great and are really sturdy, im thinking of adding some wheels so i could eventually push the whole thing around in my garage. The pallets also keep everything really accesible and its really easy to spot if something goes loose, also alot of ratchet strap points.Today i got most of everything buttoned together, and it was my first time actually getting the bike up on everything.
I screwed the front wheel holder in place after taking some rough measuremtns of where it shiuld be to keep the rear wheel right over the rotor.Just came back in from my first testrun, im as happy as ever and honestly really proud that nothing broke or flew of in the garage, it did however open my eyes to some stuff i need to make it functional.
Dynoing it on knobbies wont happen, the tiny test run i did everything shook like an earthquake, also realized the importance of an exhaust fan because the whole room was filled with smoke only from the tiny video ill link below, also thinking about adding some actual hooks into the pallets for even better ratchet points because i honestly cant be too safe with this.
Dont mind the mess
I dont know if u can post a video on here but here is the link to the first ever test run https://imgur.com/JT99Urx
Bike isnt running perfect and it isnt really a big pull, its more just to make it a proof of concept even for myself, no computer or software plugged in either at the moment so didnt get any graphs or info yet, but its coming
Now my dilemma is if i should try to do a burn out to get a diy flat dyno ready tire, buy some street tires for the rims and wheels i have currently or wait and buy some supermoto wheels when i find a good pair that fits my budget, its my dream to have a pair of supermotos on there, but its just expensive, especially with shipping from uk to sweden. But if u have a pair or know anyone thats selling or parting out their bike with sumos on it im interested for the right price
sorry for yet another long post
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Thanks mate, its pretty botched together and u can tell that its homemade, i like the charm it gives off, but if it will actually be funcitional in the end is something different, ill keep updating on here however and soon i hope to post some graphs aswell
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@Arild
Don’t you really need another roller in front or behind the electric one? To stop the wheel from trying to climb off of the electric roller?
I think when there’s two the wheel just sits in between them. Especially if you can match the force/friction between them with a pulley or chain??...
Scratch that, the rollers have to turn in opposite directions. I can’t get my head around how you’d do that.. -
@SpookDog
Not really, if u look at production dynos its often just one roller, with the bike tied down and with the stop at the front it doesnt move, however ive been thinking and my conclusion is that it probably still wont work, seeing as the roller needs to be heavier, or larger diameterThis because the engine doesnt have the same resistance on the rollers as when its on ground, this causes the engine on the bike to rev to like 13k and the roller speeda up way too fast for accurate measurements i would think, havent tested that far yet however cause i had other stuff coming up
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@SpookDog said in Engine tuning/ bike build:
Would weighting it with a flywheel help?...
I’m thinking dumbbell weight
...I know nothing about dyno’s so bare with me here...
But wouldn’t altering the weight change the amount of resistance/force needed to move the roller in the first place thus altering readings more? -
@Stevie-Wonder
Long time no hear, bud!...
Yeah, but you’d want to try and match it to the weight of the bike and rider. Don’t get me wrong, I’m no expert on anything! My head just tells me that there needs to be some resistance otherwise it would be making revolutions and not much else?
How the feck you calibrate it I don’t know... -
Small update, ive not really been in the garage since fall break ended but this is what ive done this weekend
I was curious if you could change the bushings in the clutch basket, since my engine is clanking alot and making wierd sounds and i somewhat remember the clutcj basket being somwhat loose when i put it in, so since i have another dtr basket laying in my garage, a broken one, i decided to see if it can be opened up and i was thinking if i could maybe cad up some bushings for the clutch in the bike.
This is what it looked like, and it can infact be redone if u have a sloppy basket and these bushings get worn out, the only thing is i think you would have to thread those three holes where there had previously been pins holding it all together.
I also decided to cad up an attachment to my dremel that i can use to port my barrel, since all 90 degree grinders are so expensive and ive seen other peopel doing similar things i decided to mock it up in cad.
this is what i came up with, still a rough idea tho
Might not look like anything, but it will be powered by a rubberband or something along those lines, i got this idea from two stroke stuffing on youtube on his video on a homemade 90 degree grinder https://www.youtube.com/watch?v=W6V5Piz_Uz8
Im scavenging parts from a 90 degree attachment i bought off of ebay that fits onto the dremel but it was too big to fit inside the bore -
@calum yeah i agree, i wanted to check if it was possible to change worn bushings and it looks like it is, however like i mentioned the real problem is putting it back together, my idea is to thread the holes and use some bolts and the best loctice there is but still id be somewhat worried of it coming loose
Whenever my engine is being torn out for a rebuild ill probably look into rebuilding the current basket aswell since it was alot more loose than the broken one I split
keep up the good work
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