Found where Power is Hiding, Destroyed Engine along the way...

[@crperformancetucker5065]

Maybe a destroyed cylinder is a blessing in disguise. Seems with all the port errors maybe a reprint or new casting would be a freash start.

[@dsimila1]

Or cylinder liner.

[@isaacknudsen9320]

Your short pipe seemed to work the best !

[@isaacknudsen9320]

You should run a cvt clutch

[@aeroflopper]

Why? @@isaacknudsen9320

[@geemy9675]

@@isaacknudsen9320 CVT on a Dyno is really bad especially if you are tuning the engine,because you don't control the RPM. for a scooter using a CVT you can use the Dyno to fine tune the CVT

[@anvilgardgen]

We ALL... felt your pain at the end...all that running and then..NOOOO ring snag!!! 😢 We're all behind you and really now looking forward to the next instalment. Good luck and keep moving forward....

[@FlyingScot]

Great episode and finally the best quote from you for a while Alex.." Stop Assuming". You went step by step and test by test this episode to determine the factors affecting the power output. Having watched your channel for 4 years this is a major step forward for you and your stubbornness! :-) With all the knowledege you have now, it seems next step is to design and manufacture v2 of the engine fixing all the workarounds and mistakes you have found in the first one. Attempting to fix this one and then start working on the dyno seems a redundant step. Take the time with a new design and while thats getting manufactured work on fixing the Dyno setup with another engine. Im sure we could all give you some money to get a new cylinder printed or cast. I see great things happening soon!

[@villekinnunen6357]

This! ☝😎👍

[@stykytte]

Finally!

[@garrettjones7202]

On the belt loss conversation, if that tensioner is made for automotive timing belts it it likely not intended to run the surface speeds you’re putting it through. If it is a gressed bearing it’s likely adding a lot of loss from grease sheer.

[@_David_E_]

The ring snagging is unfortunate but I feel like you've come a long way, found a lot of issues and learned a lot over the last few weeks. That's all valuable knowledge and experience. I think you need to keep going down the path of simplifying things and removing as many variables as possible. That seems to be helping a lot. Hopefully this setback can be turned into an opportunity to correct the cylinder/port design mistakes. Best of luck. 👍

[@o4games489]

For your testsetup: What about a puch e50 style gearbox? Only one big gear connected to the clutch basked directly connected to the crank. If you used a dry centrifugal clutch with stiff springs, you could also rev the engine higher before engaging with the wheel. If you could make it so it takes oil would be ever better, but a lot more work. Its a simple design that might work for you, but you lose the upside of being able to switch gears or have a variable transmission, it would be a direct drive system with almost no losses I think.

[@gpzephyr]

You've certainly come a long way in the years I've been watching you Alex. I'd be tempted to recast the the cylinder yourself like you've done in the past. But instead of nicosil coating I'd insert a cast iron liner. In addition I'd making the transfer ports all 3d printed inserts, this way you can simply adjust the port angles by printing new ones. Good luck with it all and best wishes

[@J_W650]

Hope your son gets better soon! Happy about the proress on the bike! :)

[@1950Bonanza]

Just found your sight, love it, I'm 50+ year lover of everything two stroke, but of course bikes are number one(dirt and street), outboards, model airplane engines (RC), chain saws, you name it. Love the smell of caster oil...the real stuff. I've done a lot of research into two stroke modification, modeled some port work with our CAD CAM and finite element software off hours for fun to try and get more power...but good ole trial and error sometimes works the best. I don't have access to a dyno, so its all seat of the pants stuff and timing. I've holed many pistons and broken countless rings snagging a lip. Have a crunched up Kaw H2 engine right now that broke a ring due to somebody else's lousy port work. Great videos!

[@lilletizz]

Oh look, another emotional rollercoaster from 2SS

[@dietznutz1]

Duh yeah it's called innovation and progressive 🙄 he's incredibly clever and all you can do is hate, just leave, literally nobody is gonna miss you

[@lilletizz]

​@@dietznutz1Uhm, are you alright? Having some big emotions today? It's a joke on his incredible persistence and drive. Every time we progress another issue pops up, which he challenges head on. We're all here for the same reasons so calm your white knights ass down.😂

[@fisshuman]

wich is why I love this channel, so transparent and it's show's the reality over what we usually see on experiment or development. Full of rollercoaster.

[@lilletizz]

@@fisshuman Absolutely

[@fisshuman]

@@lilletizz Yeah😂 it's a bit funny because it seem that this project almost feels like a TV show or some sort. I mean, look at his video quality. I frickin love it.

[@TheBikeMechanic]

Ya gotta swap those belts out for a chain setup Alec, cut the driveline losses by 85 to 90 percent. I know it’s messy and a pain in the ass but we’re going for gold here boss!!

[@heathfox573]

ever thought about a long intake trumpet ? incoming gas has mass / velocity therefore inertia ! creating a positive pressure for when inlet disc opens . Inertial ramming ? Heath.

[@trashmaster12345]

Mate, you have good success with 3D-printed transfers. Why not make a cylinder with huge transfers then stuff them any way you want. Just sleeve the cylinder so you can match the ports for every transfer stuffer you make? Would make experimenting with port hight, shape and angle a lot easier.

[@gg4760-k5n]

I just wasted 35min changing the carb setting on my enduro for it not to start afterwards and then wasted more time. To then go back inside, see your new video, and feel better as I didn't feel as lonely in my 2 stroke suffering lol. I don't know how you do it man.

[@colebremer902]

It seems like all signs point to cylinder with all other major potential problem areas tested. Starting with a proven cylinder design, then modifying from there would remove the reoccurring problem of too many variables being tested at once. Problem solving is going to be incredibly difficult with multiple variables/experimental designs in each test. Best of luck, this is channel is consistently putting out such great content!

[@whipplecreekracing]

Thanks for checking transfers and blowdown. I can't wait to see how it performs! Good luck Alex

[@kasuraga]

I'm glad you were able to verify the accuracy of your dyno! now we know the data we're seeing is accurate and correct.

[@mikemike0000]

I've been watching your channel for a long time now, and it blows me away to see the progress you've made! I'm pretty good with small engines, especially 2-strokes, but i definitely learn something every time i watch one of your videos. Thank you for all you do! -Mike

[@leandrogarra]

This video is a reply to all your comments.... exhaust.. dyno.. good work man

[@michellatour150]

Wishing your son a quick recovery.

[@MikeyAntonakakis]

Maybe time to try the engine dyno again? That simple RC low-pass filter circuit should clean up most of the load cell noise, so if you can get the speed signal cleaned up you should be in good shape. Maybe try MAX9924 with a VR sensor as your crank speed input?

[@ChrisB-ng3qw]

You could here what sounds like a supercharger 'whine' on the last runs. That can't be good if it's coming from that belt system. I think a new cylinder with a liner should be next considered. maybe try a few port jobs. Keep up the great work! From your everyday biker that dreams of doing what your doin in my own shed 😎

[@paultaylor9939]

Hope your son is ok kids hey been there a few times myself. All the best on your quest you will get there cheers

[@rct2]

About bloody time you found it.

[@123gtt]

This test engine has done its job, you now have the knowledge to build a better test engine, I think this next chapter will be the final way to answer all the data gained

[@hiesig4927]

Very good outcomes by this testseries it seems to me. Even though the not very neat ending with a snapped ring. I would suggest to have the clutch as close to the crank (in power travelling terms) as possible because then you can measure the losses of the chain and gears while the clutch is open and the dyno wheeling down in rpms. Keep up the freaking awesome style and content!

[@robertdixon4554]

To lower the exhaust part , just remove needed height from base of cylinder, then correct your transfer height to your desired height … also correct cylinder head volume. From what I’ve seen you do ,this would not be overly difficult.

[@saetastr]

That was exactly my thought

[@pensansproductions3278]

1, I hope your son is ok and heals quickly! 2, all this testing and that top end lasted very well. Its been a long time since a failure. 3, thank you for slowing down the peak hp screen per run. I can read it now 😊 4, carb,ignition,intake and exhaust options tested and unless the parasitic losses which seem huge on the test bed setup are the issue. It was time to correct that top end anyhow! 5, keep the videos coming. I've really enjoyed seeing things come along to this stage!! 😊

[@wrenchg3954]

what about a shorter rod? or possibly change the wrist pin location on the piston? maybe case stuffers

[@Super-Dave-Outdoors]

If you are looking for a very precise tool for grinding your transfers look at the lucky dog manufacturing contra angle tool. I have used them on 25cc cylinders. It attaches to a flex shaft grinder and accepts dental handpieces and burrs.

[@ryanharriss7950]

If my 50 revved like that back in the day, I'd have been smiling from ear to ear 😊

[@extec101]

had tested on a dyno in the past that a normal variator belt and a kevlar the kevlar "stole" a bit over 2HP on just the same engine in the stiffness and friction loss. also the rear rim its a heafty piece that weight almost twice as much as a 17" spoked wheel and that is also lots of rotating masses. tyre is the same where a normal moped 17"/120-130mm got some major weight compared to a 120/17" racing slicks.

[@clemenszink3823]

With the high loss from the Belt, you could probably replace it with 2 gears, one on the crank and one on the jack shaft in the am6. the other variant would be to cut a hole in the am6 clutch cover and run a crankshaft sprocket to the clutch assembly of the am6 direktly (i dont know if this is possible with your crankcase size, it might require cutting the Am6 Crankcase off, just keeping the gearbox half of the am6.) Best regards from Germany and best of Luck!

[@WarrenPettigrew]

I suggest a very fine pitch chain for the primary reduction and a reasonably big reduction. Belts are lossy. I have had very good results with high speed chains.

[@guyredshaw1422]

Another fab video! I didn’t understand all of it but I’m pleased to see a tidy workshop and the use of those iconic IKEA box drawers👌

[@lionelcook8522]

Your engine does sound strong, I think there would be a lot of us here who are surprised by the lower than expected numbers. Evolution, not revolution, keep it up mate, I look forward every week for the next development.

[@honeycuttracing]

We feel your pain with one step forward and 10 steps backwards, we've had project n back burner for years and can't afford to continue with it right now 😢, but eventually you'll work this out and so will we, good luck sir!

[@thedarkknight1971]

29:39 - IS THERE ANY WAY that you can replace the belt drive (from the motor to gear box) to a gear driven system? 🤔🤔🤔 😎🇬🇧

[@Swinginspanners]

I was thinking to myself... For you to take so long to load a video without notice is either a major brake through or just a major brake 😆 turns out it was both 😍😍 Love your work!!

[@AdrianRouse-e1f]

Saw of the crankcase and weld your crankcase case to the gearbox using a spacer to align where they split. Crank to clutch should be no problem.

[@YouThinkAboutThis]

What I keep hearing is the cylinder is not what you think is correct. You keep trying to work around the cylinder issues. Time to make a proper cylinder.

[@ghettogarage6687]

Pardon my ignorance, because the very limited knowledge I have of 2 strokes is purely what I've picked up along this series; but aren't all these cylinder "issues" a result of the initial idea being to have this engine forced induction? Also (again, pardon my ignorance) wouldn't "fixing" these issues mean returning to a pretty standard 2 stroke design/theory, in which case, why not use an off the shelf cylinder? It was my understanding that the idea was to push the boundaries of what is considered normal 2 stroke cylinder design.

[@espenschjelderup426]

​@@ghettogarage6687 no this is the PIP engine. The NA engine. You are thinking of the brute force engine. But I guess It's easy to get confused because he tested the superchargers on the PIP engine.

[@davidgierke7582]

You're right. The brute force engine is completely different that the naturally aspirated engine-so I'm beginning to wonder what is the sense in optimizing the later, if it has no bearing on the goal of high bhp supercharging... This is becoming a psychotic undertaking! But it's still fun to watch. @@espenschjelderup426

[@ghettogarage6687]

@@espenschjelderup426 I haven’t watched any of the brute force stuff. If the PiP started with supercharger, and then went to a pro charger, how was that not the initial idea? This has been a long journey, but if I remember correctly this whole NA thing was only to work out the problems he was having with forced induction, and prove the cylinder and crank case.

[@espenschjelderup426]

@@ghettogarage6687 no the pip engine was always meant to be a na engine. Then he sidetracked and made the brute force engine that didn't work, and got the idea to try the supercharger on the pip engine. The pip engine was designed to run at a fixed rpm. With 2 intakes. One with a reed valve or rotary valve to get the engine up to rpm, and then a intake without any valves should open, with the air controlled only by the pulses.

[@joeteejoetee]

To TEST if you are loosing power in the Belt/Bearings/Sprockets then just LOOK at them with a Thermal Camera to see IF and where they get very hot. Loosing several HP all in 1 place is a LOT OF HEAT, and that energy should show up quickly and easily -> exactly where it is being lost.

[@Bullwinkle39]

There's always something getting in the way of things going smoothly, you're an inspiration with your resilience!

[@ΘΩΔΩΡΑΣΓεωργιου]

Hi alex...try this porting...17mm exhaust on the top is 209°..transfers 28.5mm on the top cyl..is 141,41°.....34 blowdown...18k

[@TheManglord]

something curious, the 1983? Honda Fc50 beat, its an Af07 engine, theres not alot of infomation about them either, its factory about 8.8hp, which is a ton, and it uses a foot operated power valve (V-Tac), ive done a rebuild, and basicly how it works- exaust gas leaves and does a right angle out the exaust, upon opening the valve, gases can now go straight and also the orignal path, making twice the volume move which is a big power thump...i have a spare engine here if your ever curious and want one sent to you for trial and error purposes

[@Craft5ire]

The intake charge rate is still the same. Because the size of the intake pipe is still the same size as the carburetor installed earlier. Before you replace the carburetor with a smaller one

[@tomjerry6529]

Not only cylinder hight position effects port time "quality". But also same timing angles but with different rod lenghts will change blowndown time area "quality" because of different piston speeds. ;) (and in general, you'll allready know, that rising cyinder position will change transfer angle way faster than exhaust port angle. If you would like to give the tuned pipe best of pulse, I might search for the blowdown area (beginning) around the fastest piston speed for a given rod length and stroke (!) (and sure, it's not at 180° atdc). Cheers

[@bluestripes1]

cant wait to see the next design, im sure now with all the changes you wil make to exhaust duct, transfer angles, port chamfers, etc, culminating in a new version will really move you forward

[@Goultek]

I blew an engine or two when I built my race car, worth every penny, always came out more power and reliablility

[@pubbiehive]

You should maybe make the cylinder fit on an existing crankcase, like the AM6 to minimize transmission losses.

[@nerd1000ify]

A note on safety: long sleeves can get caught I the rotating chuck of your lathe and pull you in, leading to severe injury or death. Avoid wearing them while turning.

[@maxhaggberg8713]

Also never leave the chuck key in the chuck. Could be painful

[@Theis2003]

as a rental gokart mechanic i can confirm 😀

[@Tom-Lahaye]

How much impact small changes in port dimensions and position have is just unbelievable. Maybe you should look into a chain primary drive if you can't get a direct drive, a chain has less friction than a belt.

[@afflickracing1705]

1/2 way there - My 50cc bike is home next week and will get ready for Aus Speed Week in March 2024. Chasing 105mph

[@motorcyclesgoodiesdepraatp9158]

You are doing well Alex, I’m convinced you already have 20 crankshaft horsepower. Small engine then you really have to have everything in perfect condition. I advice you to take a look at rolling resistance and transmission ratio, Use wheelbearings with light rolling resistance use ZZ, A good chain, with no O-ring, nor stretch D.I.D racing NZ3, Aluminium rear sprockets, new front sprocket. Calculate the transmission ratio from crankshaft to rearwheel for a 50cc racer, or dragracer....make it the same. Make that primary drive belt narrower. You will see the power coming. Greetz J.

[@extec101]

while at it the rear cast rim its heavy stuff, would run a set of 17" cast rims on my 70rr supermoto insted of the spoked 17" ones i got on it till i had the cast rims in my hands and feelt the weight almost dubble in rotational mass.

[@villekinnunen6357]

I don't think it affects peak power

[@extec101]

@@villekinnunen6357 it wont affect the peak power but acceleration is slowed down.

[@davidgierke7582]

He has to prove it with a accurate method of retrieving T and bhp...otherwise it's all guesswork.

[@guidosamson682]

Way to high ex port!. If you still want to test thos cylinder. Shave off. 1.4mm of the cylinder base so the cylinder drops and the port durations changes. Let the pistin go in the head and reshape the compression chamber to spec. The enlage the transfer to the timing you need. And use good quality epoxy to flow and reshape them. That the only option you have at the moment. I think you know exactly what i wrote. Good luck and it will work for sure

[@keithheiskell2389]

Maybe you could try putting a deflector on the end of the expansion chamber where it goes into the cylinder to deflect the gases were you want them

[@seabeepirate]

@7:15 does that make it a good candidate for supercharging? Maybe turbocharging but that might be too much parasitic loss on the low end.

[@gdsschirra1]

The dyno setup is, as noted by others, an uncertain factor. Just brainstorming: as an electronics engineer I was wondering if there is another way of building a dyno with an electric motor used as a generator driven by the crank, motor driver and some amount of battery storage or load dump resistance. Torque than cannot be derived from inertia, but with a torque sensor in the axel it could be done. I also feel a new T-shirt design coming: "Assumption is worth nothing"

[@Scissors69]

He showed at the start of this video that the dyno setup wasn't uncertain.

[@0JThomps0]

3rd time I'll leave this message. Put a MAF on it just to see when you're drawing more air. You've got too many variables and no data as to whether it's drawing more air when you change things. You can remove the MAF when you're satisfied with flow.

[@espenschjelderup426]

I like that idea😊

[@beardoe6874]

Try to make sure your son gets good physical therapy and maybe some chiropractic work on his shoulder. I dislocated mine when I was 2 or 3 and everything was fine until my late 30s, but now my shoulder is giving me problems and I think the genesis was that dislocation so long ago...

[@chrisdawson5129]

Boost port angle is also crucial to get the best.... Which will depend on combustion bowl design and squish percentage....

[@xpndblhero5170]

I've been wanting you to go back to the stock engine for a while now so you can cut out a lot of the factors that could be messing w/ the results.... Good Luck. 😁👍

[@fxtc1332]

Hope things aren't too bad with your son. Rgds optimizing the primary drive, you might change to a 219 GoCart chain drive. No need for a tensioner anymore. Sprockets are easy to get in varios sizes and can also easily be milled.

[@lxaegg]

One thought to eliminate the belt drive. Since you are using case stuffers on the large pip chrankcase and secondary intake. Would it be possible to put the pip cylinder on the am6 chrankcase with a adapter for the boltpattern and transferports of some sort? Useing a chrank with the same stroke and rod lengh. Maybe machine down the deck of the chrank case or the cylinder to make space if needed. There wouldnt be any unknown losses anymore. One could also test a reed intake and then convert it to rotary valve. Is the chrankcase volume big enough on the am6?

[@dixracin1]

.it wasn't the friction in the assembly from the added speed that made the numbers on the dyno drop as much as it was the fact that you weren't tuned for that much load

[@benjaminritter5286]

Look how the bearings in the clutch cam Loks now. I think the pressure of the belt is creating a lot of friction.

[@OuroborosMotorbike]

I might be in love with that Triumph!

[@oziozboyt6058]

I think it’s possible that the large differences in transfer and blowdown time area is causing some problems. Bc yes the transfers aren’t a limiting factor but the overly large blowdown will hurt cylinder filling more than what’s necessary(and more than what the transfers are made for) and i think this problem is made a lot worse if the pipe is acting up(im not so sure on the pipe acting up bit) and not “sending” the pressure pulses at the correct time restuffing the cylinder with escaped gases.

[@jeeweevdee3958]

I can also recommend using a derbi engine much better transmission longer gears and stronger then an am6 i had one with a 70cc pro race a build exhaust tuned and turned out well over 20 hp the am6 engine with same setup could not even come close to that

[@upsidedowndog1256]

I wonder what one of those hollow plastic boxes between the carb and intake port would do. My old Yamaha dirtbikes didn't like them removed but not sure what in the hell they really did.

[@olefugle]

Other everlasting TV-shows like Grays Anatomy make a musical episode. When will we get the 2 stroke stuffing musical episode?

[@lawerncemiller6557]

That's as long as I've seen one of your cylinders an piston last has been a lot of 15,000 + rpm runs on that piston and cyl probably wore out things don't last long at those kind of rpm's so nows the time to make port timing changes you mentioned

[@davidgierke7582]

The situation seems dire to me. Until you get your torque/bhp measurement problem fixed, nothing else you do to the engine will matter. By the way, testing 45 and 70 bhp (at the wheel) motorcycles doesn't justify your dyno's ability to do the job at much lower torque/bhp numbers-as you learned at the end of this video. Sorry that you have to start over again with your cylinder, but you seem to be on the right path with the projected time-area numbers for the ports.Please spend whatever time and (unfortunately) money necessary to obtain and set-up an engine-only dyno, such as a simple water brake-even if you have to retrieve the data manually at set rpm points throughout the power band. Best of luck, I'm pulling for you!

[@mymodel6]

Glad i'm not the only one thinking this, he should just get a proper dyno now, no experimental stuff this time :)

[@viktorandersson7819]

The conclusion of the differences between the results between a big and small pulley isn't that the dyno is at fault, it's that the pulley system to the gearbox is stealing alot of torque. Or did I miss something?! Since he "geared up" the first pulley this efficiency loss becomes multiplied and more obvious. I think.

[@oliverscorsim]

​@@viktorandersson7819yes your correct and actually gearing up the primary always means the clutch now has an easier time as the tq the engine is making is being cut down in that gear change before it. But I do think friction is his issue. Back in the late 60s Honda had a thing with 50cc 4stroke racing their horizontal engine and when they made the dohc version they lost power due to the friction being so high at those high rpm (20-23krpm) so they went back to sohc. On the privateer level a supercharged dohc was tried and still lost power to the sohc due to friction. I would cut that am6case and weld on his mounts but sealed at the primary. Unfortunately this means his rotary valve needs to move and a ground up restart looks to be in order. I hate to say it but given the snagged ring and all the errors so far its a logical step. Doesn't need to be a total redesign but I think everything outside of the rotating assembly needs charging. I do wonder why not bring back the direct drive with a clutch? This does seem like the shortest cut to figuring the engine side.

[@viktorandersson7819]

@@oliverscorsim Or, just fitting it to a load cell dyno.

[@Scissors69]

Actually, the calculation doesn't change. It's just how quickly the rpm of a known mass is changed. 45, 70 , or 10bhp

[@yvonnetaylor6274]

could the transition from the round exhaust pipe to the oval exhaust port with a flat area around it be reflecting most of the pressure pulses in ways that interfere with the next pulses arriving . It seems that the transition would also reduce the amount of pulse reaching the cylinder and making some sort of gradual transition from the round pipe to oval port would improve the concentration of the pulse to the cylinder , this could be done in the port or the end of the pipe or a combination of both.

[@acontadoquim]

Are you going to take advantage that the cylinder is scratched to raise the transfers? I think its a good idea since you might need to plate that thing…

[@mwasy2713]

Love to see a man on a mission

[@jacquesevans1023]

Have you looked at the most recent 125cc kart engines from vortex? 2 strokes are still being developed in kart racing. They would probably be the most powerful 2 stroke engines per cc if they did not have carb/ ignition restrictions . Maybe worth getting hold of a barrel from one of them to see what they are doing

[@kevin-hp7vg]

Look at the “2fast” engines for 50cc and scooters, they are 100cc engines which manage to put out around thirty horses 😋 it’s crazy

[@gsestream]

so the exhaust pipe has a frequency response as an organ pipe, something between 20-20000Hz, well if you expect 15kHz of the engine, then the pipe has to pitch up to that same 15kHz tune. maybe a pipe resonant analysis device separately could be nice. well rpm / 60s = revolutions per second = Hz, so 15000rpm / 60s = 250Hz exhaust pipe tune, thats a pretty low pitch tune. thats pretty much a tv test tune pitch Hz lol. note: tapered piston cylinder ignition section would take some initial force from the cycle btw, because narrower initial piston/cylinder combustion pressure area. rip engine :)

[@2SmokeyGuru]

Smaller exit on exhaust maybe?

[@turkeyboyjh1]

I could definitely see a 4-6 hp lose through the belt, 2 pulleys and a tensioner, the transmission and the 2nd set of crank bearings and the chain, there is a lot of parasitic lose there, also the primary belt drive looks a little tight

[@hunnybunnysheavymetalmusic6542]

If you could manage to have a trombone style exhaust, you should be able to change the pipe length according to RPMs. Get that sonic barrier to be timed shorter as your engine speed increases. I realize that is entirely outside of the blow down and transport issue... Well... Kinda. They work together dynamically and synergistically. It is not an either/or, but a 'both' type situation.

[@dmxsterryk]

I’m sorry, but I’ve been saying all along that parasitic loss is a major issue, especially on an engine this small. A new set of custom billet cases is in order no? 😜

[@willemulrich2625]

Misschien is het dit, misschien is het dat, maar als je de basis principes van een tweetakt negeert zal het nooit wat worden met z'n warhoofd. Als je krukas ruimte te groot is zal je nooit genoeg aanzuig kracht hebben om voldoende brandstof in de krukas ruimte te zuigen en ook te weinig kracht om de brandstof in de cilinder te pompen. Kijk eens naar een tweetact racer van een japanse fabrieksmachine , en ook eens naar een nederlands tomos 4l blok waar een extra kamer aan de krukas ruimte is toegevoegd om te voldoen aan de nederlandse vermogens beperking.

[@MuntyScruntFundle]

Ouch! Could this be the time to design another cylinder with your ports setup "just right"?

[@maxbuchner3059]

Silencer is also important! And dont forget the length of the end pipe

[@TJPDmember]

In theory, a good strap set-up will be about 70% efficient at transmitting power. A chain system is about 95% effective. I'm also wondering, did you account for the different gearing when doing the last pulls? Because wheel speed will be different but it's not supposed to change the power numbers, neither does a different gear ratio.

[@reddevil663]

Where can I get the programs at 18:00? :)

[@trevor6814]

I’m curious to know as well

[@2STROKESTUFFING]

Engmod2t

[@afleetcommand]

Two things have bothered me since the beginning of this series. Cylinder scavenge & primary compression. Simply more x-sectional area in of itself for exhaust & transfers doesn't equal better scavenge. The flow characteristics do, curious if the top of the piston gives u evidence as to how that scavenge is working. Direction the transfers send the gasses , how the cylinder fills etc. all adds up. And primary compression to create the velocity up the transfers into the cylinder. SO I have to assume you have designed around this. Your knowledge far exceeds mine, but the "feel" I get hearing that motor run has always reminded me on one with either too much case volume or intake duration. For fun & games my 70cc Husqvarna build has the blow down in the 20--22 degree range for power in the 10-12,000 rpm range

[@riceburner32]

Could you leave the display box with the hp and tq numbers on screen for a few more seconds? My old eyes aren't fast enough to read what is on the screen. TIA s.r.

[@windyworm]

Another great video! Cant wait to see how the the new improved cylinder does.

[@turtlemann14]

so would it be worth using a high ratio to get more torque going into the trans, and decrease the final drive so there is less oil and air resistance with slower spinning gears and shafts? or maybe a direct drive 12T: 440T gear set lol i don't know much about two stroke porting, but with a very wide port, couldn't you hold cylinder pressure longer and still get it to blow down, pull a fresh charge in, seal transfers, and re pressures from the exhaust pulse much faster? aka less duration with a much shorter pipe than "normal" to match. id say the transfers would have to be closer to the top the the exhaust port as well due to the speed at which it can dump exhaust gasses. that alone though seems like it would make reversion bad. maybe a tesla valve or a reed in the transfers.

[@michaelisola6328]

Have you looked into the Aprilla RS50 that made 27 HP ? And possibly adapt some of that technology to your engine . Just a thought 😊

[@matthaigh5296]

Most interesting episode for a while, really enjoyed it

[@ZPROHASZKA]

I did watch your torque figures (max. 5.6 Nm), since (for the same intake pressure efficiency) the engine takes the same amount of energy each stroke. So, at a given RPM, the torque tells, if the cylinder is filled properly (if ignition timing is kept constant). This is good to compare, which pipe gives its best resonance, and at which rpm. Btw, the KX 60 has 9Nm of torque, so 7.5 from 50cc seems achievable. Of course. your design lowered it, to be gained back on increased RPM. Based on the KX60, 12.5 hp from 50cc is a good baseline, which you allready have, around 16000. I wonder if the torque at 16...18000 could be raised to 6-8 Nm by better gas-dynamics and pressure waves.

[@acurarl9929]

Centrifugal clutch. Run chain from your engine to tire

[@guidosamson682]

Alex i dont know if you can find an epoxy that can witstand the extreme exhaust gas temp. If there is one. Lower the timing with epoxy to 196 degrees. I have tried it and it worked. For 2 of 3 tests. But then it got lose and the epoxy went in to the pipe. For tohe 2 or 3 runs it was fantastic

[@trashmaster12345]

If there is a CV-joint capable of 20k RPM why not mount the engine inline with the AM6 shaft (the driven pully you have). It would make the engine a bit easier to work on as well I guess.

[@svenodsvik569]

I think you have the tension pulley on the wrong side. It should not be on the pulling side but allways on the pushing side from the crankshaft. And chain has also less friktion than a belt.

[@rachalhollier5679]

How come your pipe doesn’t have a stinger? I use a FMF silencer on my Honda Dio pipe as the stinger. It’s like a vertical Jog pipe for my hybrid Minarelli engine and it turns over 15,000 rpm’s with me on it , that’s under a load with the wind in my face. It didn’t do that before with a 4” stinger that I think was to small. The FMF Silencer came off my Franco Morini Motori 60cc water cooled engine. Now my Franco Morini S5GS 50cc needed a 12” stinger 1/2 the diameter of the engine exhaust size coming off the cylinder. Maybe your transfers are not high enough for the rpm’s your trying to turn. Try a slip on stinger it can’t break what’s broke,,,,,,

[@Ratkill]

This project has so much educational value I love it. Every episode is working through real-life applications of a lot of deep theory that can be hard to grasp with numbers only. Literally the only videos I watch all the way through without clicking out to other tabs lol