I don't even care if we never see the results we are all hoping for. I love this channels content... You could be clearing out a cat litter tray for all I care you would make it enjoyable 😂😂
@@caseysmith5585absolutely agree, I have been watching actively since the 30HP 50cc 2 stroke video, when it caught my eye and there i am a active subscriber that watches every video few minutes after posting. Really one of my most favourite chanells.
MY GOD MAN!!!...Over the years I have written you about this project (in depth) several times!!!...Your reinventing the wheel approach to such a complicated mess of factors is infinitely impossible!!...The FIRST thing you need to buy (or make) is a "flow bench"!! ..With your love if small detail, I know you will enjoy it!!..This is the ONLY way you can make so many small changes without all the machine work and time you spend building parts!!..All these changes (Ramp angle, port size and diameter, etc. etc).can be figured out mathematically. Buy the operating manual for a "Super Flow" flow bench!!!!!...It has all the formulas for this work!!..You can then "time" your "pulses" for intake and exhaust to maximize your efficiency!!...You can make ALL your designs out of plastic, etc. and then copy them in metal when they work 100%...Please buy the manual (it's cheap!)..It would have saved you YEARS of time and you can figure out EXACTLY what the lengths are from the tip of your velocity stack to valve, along with sizes and shapes!!...Once you read the manual..you WILL understand.... This is from a 72 year old Race engine builder for any kind of performance engines...Love the channel, just hate to see all your time and effort spent, pissing jnto the wind...👍👍👍🗽🇺🇸
It is a 2 stroke. Flow bench is useless on two stroke because you have pulses. On 4 stroke pulses are many times weaker because valves open slowly not fast as piston opens them on 2 stroke. The solution is pulsating flow bench, but best pulsating flow bench is engine itself mounted on a dyno.
@@GlobalSLO There are several pulses in a 4 stroke...the bench and it's purpose, is to "time" these pulses (by changing any of the thosands of flow related parameters) so it maximizes suck and blow ( to state it simply)...2 strokes definitely have the same issues..the bench will save all the wasted machine work due to trial and error engineering...and the majority of these factors can be figured out mathematically...so I disagree..
@@billrandell4641 you can figure them out mathematically, that's why we have EngMod2t simulation program. Also Twostrokestuffing has his version. But flow bench is useless. Flow has little to do in a two stroke because you can't simulate strong pulses. Pulses are 10x stronger as in 4t. If you remove exhaust on 2t 50cc 20hp bike you get 3hp. If you remove it on 4t you loose like 10% of power. Even the master of two strokes Jan Thiel said he never used flow bench, even at Aprilia GP 125cc development where they had a lot of resources.
@@GlobalSLO Hello there. When Alex designed PiP he used EngMod2t and did numerous simulations which seem to have not being true to form. It was Alex's desire to make the worlds most powerfull 2 stroke engine his way or not at all! He simply did not want to run or alter a known design. Why did the Engmod2t desisn not work as simulated so many times over the years? Alex is a grand chap, and we all love him to bits but some times all logic goes out of the window not just the PiP engine design. Over a year ago I posted a comment on why doesn't Alex reduce the crancase volume with epoxy putty doing it the proven old fashioned way. Sadly, this hit a major sore nerve with Alex and he said on air that it was his project and he would do it his way, end of story!!!!! which I can now understand. Alex has said many times how he knows he has taken lots of people down his imaginary rabbit hole with him and he feels for them. We need to remember the principle reason of this project was to use a fully resonant induction system using no disc or reed valve designed on EngMod2t. I could go on for ever as I've followed Alex from the very begining 6 years ago. I can't remember the name of the major company who designs 2 stroke engine parts at the moment but one of there big selling points is they use flow bench technology. Right it's nearly 3.30 AM and I need to get some shut eye! This artical is not intended to pull any person down in any way. When we used to build our own race bikes in the early 70's the main point was to reduce crankcase volume as much as utterly possible and the principle worked very well and I hold with it today. Night all.
Try adding a spacer to your pipe, increase the header length 20-30mm and see if it'll pick up in the lower end some. You've changed so much, but nothing with the pipe.
I raced a 135cc in my kart. I did tell him about how important the pipe is, but nothing yet. I told him to try a "Slippy Pipe", but nothing yet. He's stuck on his ways. My engine was happy @16,000 and lasted 1 hour for the win, I was the points leader.
Yep I've been screaming at Alex extend pipe I'd go 100 to 150mm to start with but in the 19k range he may need 300mm extension. Port helped but it's still suffering 10500rpm on , pipe is what makes a 2st
An egt would give you a good idea of where and when you’re having fueling problems. You’ve already have a thermocouple on the sparkplug, add another to the pipe. It will make your experiments less frustrating.
Great work! This is. A good first step for more systematic logging. You could log: intake manifold pressure and temperature and probably also mass air flow. Also exhaust pressure and temperature. Would make it much easier to actually get a good idea what is hurting performance and qualifying your guesses more :)
sheesh what an emotional roller coaster of an episode... I am glad you found and started to eradicate some bugs. well done and love your work keep it going 👏 👍 💪
exhaust rotary valve could probably do wonders with supercharger by keeping the stuffed mixture in the cylinder but can they work with the boost and the cylinder compression..I don't thi k rotary valve are meant to withstand "high" pressure
I just love your extremely droll sense of humour, your skill and your vision. All power to you - and hopefully some spillage onto the dyno numbers. My favorite channel.
I've enjoyed your videos for a long time, but I think this video is a good showcase of not only your strengths, but your weaknesses too. I don't think your workflow is incremental enough, and you're likely overshooting the sweetspot because of it. Just try varying one thing at a time, back and forth in small steps, to really narrow down where the sweetspot is for every part of the system. The position of those sweetspots will change, so you'll have to circle back and adjust everything all the time, but it's the only way you'll ever reach the extreme performance you're aiming for. It's not about mining for ideas, hoping you've come up with the solution, worrying that it won't work this time either. It's a way more relaxed mindset. It's "let's change this half a degree, and if the dyno numbers improve, change it half a degree more." for a long long time. That's where the horsepower is.
Doing one change at each test is definitely the way to go. Takes more time, but only then can you determine what works and what not So glad to see how your channel has grown. Well deserved!
I cherish every minute with you. The music while wearing my headphones is so awesome! When you went under the table to sulk I blurt out loud with laughter. It was encouraging to see it pull through a couple of gears at the end. I built 3 honda MB5's with stock CR 80 engines with Dave Miller expansion chambers on each of them and your bike on the dyno brings back so many memories/sounds/and speed! Keep it up!
He’ll most probably get there in the end, but personally I hope it’s a long time from now. Because shamefully I enjoy the roller coaster ride of failures and successes. Yes I’m a glutton for punishment and I love this channel, lol! More please👏
Don't worry tho, if he find success that won't mean he will stop. Alex is cursed with curiosity and obsession to find out, he will never run out of topic to smash his brain against. Great for us, probably not so great for his mental health tho.
nope he does not stand a chance of ever finding out what the power band is .. and what the popular belief is today is telling everyone that the expansion chamber acts like a supercharger making a pressure wave forcing the fresh unburned fuel that is wasted in the pipe to turn around 180 degrees and go back up inside the engine to make more power ..and if you all believe a story like that , ill bet you all would stick your head in a fire if i said you will see hell
Imagine how many cylinders, heads, reed blocks, Carb variations, exhaust angles and lengths. Yamaha, suzuki and honda went through in their 2 stroke racing days. Love the Channel, love the thought process. Thank you for sharing.
I think the journey of finding what it isn't has been much more enjoyable than if you were to just have gone straight to this. Looking forward to some success! You're the rob dahm of 2strokes ;P
Your smile at the end of the video, after seeing a lot of progress with the exhaust, Made me very happy. Keep the hard work, hope to see big figures in HP the next episode
It truly helps me understand why I buy R+D designed stuff and 'proven' things for my engine (4 cyl. car engine) because WOW the differences here are soooo small, yet make SUCH a huge improvement. The R+D and Trial and error is what you are paying for when you truly want to just 'build something good first time'....vs all R+D yourself.
Back to basics is looking good, the exhaust port and chamber fillers have made a difference, I'm hoping we see the brute force concept come back into play now. ANOTHER GREAT EPISODE 👏👏👏
Mr 2 stroke I've watched you for ages an I admire what you do ... in times when you feel like giving up just remember if it was easy everyone would be doing it .... aswell once apon a time everyone thought the world was flat an who ever said it was round was crazy you sir are a innovator to the 2 stroke world an when you finally crack the code your be written in books as a legend not a crazy mechanic in his shed !
From basic pumping physics that stepping you mention will create turbulence losses and I think also affect the resonance frequency of the exhaust pipe. From speaker theory I know that a tapered tube which is constrained at the end it acts as a longer tube. Think Voight speakers.. I think turbulences losses have the same effect as a volume change losses in this situation, so I would bet that a smooth transition would work the best. Cant wait to see the next vid!
I would like to see the deathtrap on that dyno again at the start of a video so we can see the power it makes as a reference, I feel like this has taken a big step back from the early days of the brute force concept engine, that with the single rotary valve seemed like the best version in my opinion
Always enjoyable to watch whether up or down, winning or not quite winning. These videos give me encouragement to persevere with my own projects when things don't go well.
It was hard seeing you so beat down, luckily you found a way back. A true roller coaster as somebody else posted! Keep up the good work and never change!
I had this Koiritz twin two stoke engine made in 1976 apart and was looking at the intake transfer ports and the angle at which they shot mixture into the cylinder. The left and right A intake ports were the widest ports (about 3-4 times wider than the B and C ports) and would push air towards the backside of the engine away from the exhaust port while the B and C ports which were about the same width looked like they would help move the mixture upwards into the top of the cylinder and help tumble the mixture coming from the A transfer ports. This engine ran without a pipe on it. When I was looking at this old engines conservative design (55hp from 440cc) I was thinking about your radical port areas and how much you rely on exhaust pulses to keep the mixture in the cylinder. Neat to see this idea of port direction and size being explored again.
23:10 - your face says it all. The suspense builds once again. Your videos are so enjoyable to watch, thanks for another quality episode. See you next time!!
Trial and terror!!! There isn't any other way 😂 Super action packed episode 🤙 Love your drive and stamina, we're cut from the same cloth 😜 my 71 x 62 241cc took me over 10 years of struggle. It's worth it in the end, I jump on it, and it rides like a factory bike on steroids @12,500 rpm. I really don't want to have to pull it down anymore tho 😂
it's so nice to see that little smirk back on your face again mate that's the spark the little ember back there flaring back up for the first time in months
In the intake duct works an inward-contraction duct, and the exhaust duct acts as an outwardly expanding duct. Hopefully Google translate made a sensible translation, this too needed to be corrected.
Your exhaust port may have equivalent area to your port area, but due to that extremely thin oval shape, it will be *effectively* much smaller because of the boundary layer of air that forms where moving air touches a stationary surface. For some reading on the subject, you can look at things written about the flow of oval-shaped exhaust vs circular. An oval shaped exhaust of equivalent area to a circle will flow less, because more of it is in the turbulent boundary flow area. I have limited 2 stroke experience, but in 4 stroke engines the optimal exhaust port shape is like a D, but with the flat part on the bottom and the curved part facing up. Porting the bottom of your exhaust port so that it is flat, and the top is the original oval shape, would probably significantly improve exhaust flow. I see you came to a similar conclusion on your own in the latter half of the video, but I wanted to try and explain some of the mechanics behind that in case it might help you later. In 4 strokes at least, the step going from the exhaust to the port is generally a positive thing. There are even headers that have an additional step-up in size. If you can with CFD, maybe calculating the area of your cylinder ports minus their boundary layer, and making that equivalent to the exhaust port minus the boundary layer? You deserve the positive results man, and I'm happy to see it. As a viewer though, the journey is just as interesting as the destination. Is it just me, or does it sound cooler with the big exhaust port?
yup, this! Maybe Alex can do some 3D steady-state exhaust port sims (based on exhaust port delta pressure) to see that boundary effect impact on flow rate. And then adjust the port until it gets closer to the 1D sim flow rate.
You are my favorite creator. I enjoy every single video you post. Your camera angles and video quality are the best no one touches your style buddy please continue doing what you're doing. Congratulations 🎉🎉🎉
Opps...too much coffee...article is a year old...lol...but good summary... Alex, you are on your way I like to cheer you on in Utah when you return. I lived in SLC 1981-1983...my bikes at the tine 1979 IT-400 and 1970 Yamaha 350 R5...buddy drove new Husky 1982 430 WR....then broke his leg... I kept up but the Husky was faster. We rode once towards the flats...lots of wide open area to get the wick up and all the way open. Once I went to Draper...thru the back way...too cheap too pay...went to the top to witness Widow Maker hillclimb. Two made it over in 2 hours... How did I get the bike there ?...I hauled using a 1965 VW Bug...powered with my built 1835....another story...lol. The bike was strapped to the rear bumper. In that VW, no one could pass me going up Parley summit hill on i-80...lol This will be the end of my rambling... It's all good
I think you need to do one of two things. Adapt the aprilia cases, that you engine is coupled to, to verify your cylinder, or, put a known good cylinder onto you cases. This way you will know where to start looking
The only thing that I can think of is maybe a clear coat of the pla stuffers. At high rpms, it may be pulling air right through the print. I do some printing, and it is usually not waterproof.
My heart sank when you started running the engine after the transfer channel mod. But seeing the increase in HP after the exhaust mod im happy you got some part of the smoking gun. I love this channel for the exploration/ trial and error! Keep it up!
Your air compressor was trying to to tell you something... make power and make it loud, not compressed air coming out of a small port. Please keep the videos coming, love them, Cheers.
Should have gone with a malossi mhr, geometry is on point on these cylinder. BUT the suffering is more interesting, the way you try to improve your part is really inspiring.
@@geemy9675 The RF50WR competition is just the best on the market, but you have to use every Bidalot hyper sport part for the best result, the adaptable one is the best to throw on a stock crackshaft and will accept many parts and tune with no hiccups, but in my opinion, and knowing personnaly mr Bidalot, i won't use them to experiment, just to have something that will do exactly what i ask them to do.
Slight exhaust leak, added an oring at the end of the vid. There's a slight water leak where the hose connects to the head, occasional droplets hits the header.
Ok, that makes sense. I was worried the pipe wasn't working with the right resonance causing the pressure to build and push out where it wasn't supposed to.
So hard to see you struggling trying so hard for your ideas. Keep going my friend the solution may seem impossible but your engineering logic will prevail. Nobody's tried harder than you. Everybody who follows your site wants you to succeed Take care matey look forward to success if anybody deserves a victory its you Arthur
From an aerodynamic point of view, the "hook" doesn't do shit. It creates a stagnation zone, and the gas continues on in the mean direction of the port anyway...
I love your efforts and showing these lessons. The velocity of air at a port wall surface is zero and increases exponentially away from the port surface. Its the boundary layer effect. You have on those wide skinny ports an overlapping boundary layer with near zero velocity for much of your port cross section. So what I'm saying is you want the most cross sectional area with the least amount of port surface area. Perfect circle my friend.
Definitely need to revisit the exhaust. For any 2-stroke engine that you want to run at very high RPM, the pipe diameter should increase into the expansion chamber at a slower rate than the decrease back to a smaller diameter happens. This is especially important with this engine, since the piston vs crankcase volume ratio and compression ratios are both expected to be much larger than typical.
Nice to see and hear PiP doing so well. The only thing I have left over from my engine tragedy is the 28mm carb which has larger power jet fitted made from a 5mm round jet. This ran very well, I even fitted a large pilot jet which I used as a fine fuel control at high RPM. If you want it and want to use it, it's yours. I fully understand your sentiment re not just wanting to tune a standard engine. Please, tell me what this music is you used. PS, it's the old adage. You have to get it out quicker than you put it in. PPS, would you ever consider blocking the B port ducts with toilet paper and just try running it on the A ports. Your getting there!
Another thought. Barrier gases on exhaust duct due to narrow height. Turbulence near walls so you get Eddie currents on narrow passages, so even if it was 100% of exhaust port it wouldn't flow like a round channel. Yes exhaust
The step in the exhaust on return of spent gasses won't let you take advantage of the exhaust pulling the intake charge out and then stuffing it back in before the piston closes the port.
It's a simple job to mould exhaust paste to make a nice transition but at 16000 it didn't last long in my test engine but proved a point and dirt cheap.
Here's my theory. There's a reason exhaust ports are not normally so flat. The walls of the port create turbulence within a certain distance of them as the exhaust gasses try to cling to them. It's caused by the friction of the gasses as they flow down the port. The further you get from the wall, the less turbulence there is. So if your port is quite flat like yours was, there's more turbulence almost everywhere in the port compared to a rounder shape.
Hello Chris. The shape of this exhaust port came from the desire to run a 100% of bore exhaust which sadly failed. A bridge was later welded in to allow the cylinder to be used.
The gentlemen that mentioned the use of an see through cylinder head is got a good point, because if you can adjust the actual flow pattern, and see how much it changes the power curve. Then adjustable vanes in the intake that allow you to curve the airstream to the optimal position to increase the flame kernels to work to your advantage. This would also give you a better idea of optimal position for the spark plug location in the cylinder head itself. Also you can actually play with different designs for the combustion chambers like they do with cylinder heads on automotive designs. Such as the hemispheric head used by Dodge, are different designs by the other engine programs like Honda indi engines, the options are unlimited by examining many different types of combustion chambers, because although the two cycle engines are unique in a way, but there's been so many different changes over the last few decades that unless you try to open your mind's eye to all the different manufacturers designs your trapped in a never ending circle chasing your tails
Peak horsepower was about negative 8. Progress! Also I really liked the music here. Felt like watching the first pirates of the Caribbean movie. I kept waiting for Kira Knightly to pop out but no such luck.
I don't know how you keep going I watch every week hoping for a brake through your stress levels must be ridiculous 😅keep going I want the supercharger back
I love all the fun and nonstandard stuff you do dont give up on your non bog standard way of doing things that is where true advancement and true boundary pushing resides at
Ok , after watching the whole video I'm getting frustrated 😂😂. On a 2 stroke you cannot use different port timings and exhaust layouts without altering the expansion chamber pipe design. They all work together ! I have a feeling that your throwing stones in the bush hoping to find the silver bullet. Go back to basics ! You have the best simulation program in the world ! Use it and you will get amazing results 😉😉 Hint is Vannik 😁😁
Dont know too much about 2 strokes but about 1:50 at the video you are explaining the transfer ports, yours vs the convetional one, there is differenrence (if I was able to follow). The hook design will decelerate the flow and increase the pressure at the exit area. Your desing is doing the opposite as the port narrows down at the exit area. Intuitively you would like to have low velocity and high pressure flow entering to cylinder, not vice versa. This might have something to do with the power out put.
And now try it with the weird angle porting just for the information. Big exhaust, you only have so little time to scavenge the cylinder. Then play with the pipe to stuff the excess back and see power!
I don't even care if we never see the results we are all hoping for. I love this channels content... You could be clearing out a cat litter tray for all I care you would make it enjoyable 😂😂
😂Thanks!
I've been following for over 2 or 3 years now it never gets boring 👌
🤣 My thoughts also! 😜
Agree!
@@caseysmith5585absolutely agree, I have been watching actively since the 30HP 50cc 2 stroke video, when it caught my eye and there i am a active subscriber that watches every video few minutes after posting.
Really one of my most favourite chanells.
I love the fact that you don’t hide the failures, this is why I watch your channel.
MY GOD MAN!!!...Over the years I have written you about this project (in depth) several times!!!...Your reinventing the wheel approach to such a complicated mess of factors is infinitely impossible!!...The FIRST thing you need to buy (or make) is a "flow bench"!! ..With your love if small detail, I know you will enjoy it!!..This is the ONLY way you can make so many small changes without all the machine work and time you spend building parts!!..All these changes (Ramp angle, port size and diameter, etc. etc).can be figured out mathematically. Buy the operating manual for a "Super Flow" flow bench!!!!!...It has all the formulas for this work!!..You can then "time" your "pulses" for intake and exhaust to maximize your efficiency!!...You can make ALL your designs out of plastic, etc. and then copy them in metal when they work 100%...Please buy the manual (it's cheap!)..It would have saved you YEARS of time and you can figure out EXACTLY what the lengths are from the tip of your velocity stack to valve, along with sizes and shapes!!...Once you read the manual..you WILL understand.... This is from a 72 year old Race engine builder for any kind of performance engines...Love the channel, just hate to see all your time and effort spent, pissing jnto the wind...👍👍👍🗽🇺🇸
It is a 2 stroke. Flow bench is useless on two stroke because you have pulses. On 4 stroke pulses are many times weaker because valves open slowly not fast as piston opens them on 2 stroke.
The solution is pulsating flow bench, but best pulsating flow bench is engine itself mounted on a dyno.
@@GlobalSLO There are several pulses in a 4 stroke...the bench and it's purpose, is to "time" these pulses (by changing any of the thosands of flow related parameters) so it maximizes suck and blow ( to state it simply)...2 strokes definitely have the same issues..the bench will save all the wasted machine work due to trial and error engineering...and the majority of these factors can be figured out mathematically...so I disagree..
@@billrandell4641 you can figure them out mathematically, that's why we have EngMod2t simulation program. Also Twostrokestuffing has his version.
But flow bench is useless. Flow has little to do in a two stroke because you can't simulate strong pulses. Pulses are 10x stronger as in 4t. If you remove exhaust on 2t 50cc 20hp bike you get 3hp. If you remove it on 4t you loose like 10% of power.
Even the master of two strokes Jan Thiel said he never used flow bench, even at Aprilia GP 125cc development where they had a lot of resources.
@@GlobalSLO Hello there. When Alex designed PiP he used EngMod2t and did numerous simulations which seem to have not being true to form. It was Alex's desire to make the worlds most powerfull 2 stroke engine his way or not at all! He simply did not want to run or alter a known design. Why did the Engmod2t desisn not work as simulated so many times over the years?
Alex is a grand chap, and we all love him to bits but some times all logic goes out of the window not just the PiP engine design.
Over a year ago I posted a comment on why doesn't Alex reduce the crancase volume with epoxy putty doing it the proven old fashioned way. Sadly, this hit a major sore nerve with Alex and he said on air that it was his project and he would do it his way, end of story!!!!! which I can now understand. Alex has said many times how he knows he has taken lots of people down his imaginary rabbit hole with him and he feels for them.
We need to remember the principle reason of this project was to use a fully resonant induction system using no disc or reed valve designed on EngMod2t. I could go on for ever as I've followed Alex from the very begining 6 years ago.
I can't remember the name of the major company who designs 2 stroke engine parts at the moment but one of there big selling points is they use flow bench technology.
Right it's nearly 3.30 AM and I need to get some shut eye!
This artical is not intended to pull any person down in any way.
When we used to build our own race bikes in the early 70's the main point was to reduce crankcase volume as much as utterly possible and the principle worked very well and I hold with it today.
Night all.
Try adding a spacer to your pipe, increase the header length 20-30mm and see if it'll pick up in the lower end some. You've changed so much, but nothing with the pipe.
I raced a 135cc in my kart. I did tell him about how important the pipe is, but nothing yet. I told him to try a "Slippy Pipe", but nothing yet. He's stuck on his ways. My engine was happy @16,000 and lasted 1 hour for the win, I was the points leader.
full of your opinion! Also, +10-20mm could work wonders on the belly now that the cylinder can breathe.
I agree He should be trying a lot more changes in the pipe. specially now the change in outlet size.
Yep I've been screaming at Alex extend pipe I'd go 100 to 150mm to start with but in the 19k range he may need 300mm extension.
Port helped but it's still suffering 10500rpm on , pipe is what makes a 2st
@@paddy2661 Its is its supercharger.
Longer and bigger exhaust pretty sure that's a big one of your problems🙂 from a dragracer on 2strokers.. May the speed gods be with you😁
An egt would give you a good idea of where and when you’re having fueling problems. You’ve already have a thermocouple on the sparkplug, add another to the pipe. It will make your experiments less frustrating.
So glad with all the progress with the engine have been following for a couple of months and the small progress made each week is so rewarding
Great work! This is. A good first step for more systematic logging.
You could log: intake manifold pressure and temperature and probably also mass air flow. Also exhaust pressure and temperature. Would make it much easier to actually get a good idea what is hurting performance and qualifying your guesses more :)
sheesh what an emotional roller coaster of an episode... I am glad you found and started to eradicate some bugs. well done and love your work keep it going 👏 👍 💪
I think it is because all the cool stuff is missing, like supercharger and double rotary exhaust valves 🙂
exhaust rotary valve could probably do wonders with supercharger by keeping the stuffed mixture in the cylinder but can they work with the boost and the cylinder compression..I don't thi k rotary valve are meant to withstand "high" pressure
we dont want to hear this but how about normal 4 stroke valves?
I just love your extremely droll sense of humour, your skill and your vision. All power to you - and hopefully some spillage onto the dyno numbers. My favorite channel.
I've enjoyed your videos for a long time, but I think this video is a good showcase of not only your strengths, but your weaknesses too. I don't think your workflow is incremental enough, and you're likely overshooting the sweetspot because of it. Just try varying one thing at a time, back and forth in small steps, to really narrow down where the sweetspot is for every part of the system. The position of those sweetspots will change, so you'll have to circle back and adjust everything all the time, but it's the only way you'll ever reach the extreme performance you're aiming for. It's not about mining for ideas, hoping you've come up with the solution, worrying that it won't work this time either. It's a way more relaxed mindset. It's "let's change this half a degree, and if the dyno numbers improve, change it half a degree more." for a long long time. That's where the horsepower is.
I love your enthusiasm and dedication to the engine. I've been working on my race car for 22 years and still love every minute of it
Doing one change at each test is definitely the way to go. Takes more time, but only then can you determine what works and what not
So glad to see how your channel has grown. Well deserved!
Exactly what i was thinking. He has a habit of going down rabbit holes when chasing problems
I cherish every minute with you. The music while wearing my headphones is so awesome! When you went under the table to sulk I blurt out loud with laughter. It was encouraging to see it pull through a couple of gears at the end. I built 3 honda MB5's with stock CR 80 engines with Dave Miller expansion chambers on each of them and your bike on the dyno brings back so many memories/sounds/and speed! Keep it up!
He’ll most probably get there in the end, but personally I hope it’s a long time from now. Because shamefully I enjoy the roller coaster ride of failures and successes. Yes I’m a glutton for punishment and I love this channel, lol! More please👏
Don't worry tho, if he find success that won't mean he will stop. Alex is cursed with curiosity and obsession to find out, he will never run out of topic to smash his brain against. Great for us, probably not so great for his mental health tho.
nope he does not stand a chance of ever finding out what the power band is .. and what the popular belief is today is telling everyone that the expansion chamber acts like a supercharger making a pressure wave forcing the fresh unburned fuel that is wasted in the pipe to turn around 180 degrees and go back up inside the engine to make more power ..and if you all believe a story like that , ill bet you all would stick your head in a fire if i said you will see hell
Honda GP Barrels , you change the step length of the oval step to round transformation with different fuel and exhaust pipes !
man it sounded sweet sat at 14k rpm. this channel has been one long evolutionary learning process. good going dude.
CROM!
@@murmenaattori6 he laughs at your 4 winds
Imagine how many cylinders, heads, reed blocks, Carb variations, exhaust angles and lengths. Yamaha, suzuki and honda went through in their 2 stroke racing days. Love the Channel, love the thought process. Thank you for sharing.
Your a good engineer. Keep up the good work. The fun is in learning and experimenting. Best part of the whole experience. Your on the right track.
I think the journey of finding what it isn't has been much more enjoyable than if you were to just have gone straight to this. Looking forward to some success! You're the rob dahm of 2strokes ;P
Your smile at the end of the video, after seeing a lot of progress with the exhaust, Made me very happy. Keep the hard work, hope to see big figures in HP the next episode
It truly helps me understand why I buy R+D designed stuff and 'proven' things for my engine (4 cyl. car engine) because WOW the differences here are soooo small, yet make SUCH a huge improvement. The R+D and Trial and error is what you are paying for when you truly want to just 'build something good first time'....vs all R+D yourself.
Back to basics is looking good, the exhaust port and chamber fillers have made a difference, I'm hoping we see the brute force concept come back into play now. ANOTHER GREAT EPISODE 👏👏👏
Mr 2 stroke I've watched you for ages an I admire what you do ... in times when you feel like giving up just remember if it was easy everyone would be doing it .... aswell once apon a time everyone thought the world was flat an who ever said it was round was crazy you sir are a innovator to the 2 stroke world an when you finally crack the code your be written in books as a legend not a crazy mechanic in his shed !
From basic pumping physics that stepping you mention will create turbulence losses and I think also affect the resonance frequency of the exhaust pipe. From speaker theory I know that a tapered tube which is constrained at the end it acts as a longer tube. Think Voight speakers.. I think turbulences losses have the same effect as a volume change losses in this situation, so I would bet that a smooth transition would work the best. Cant wait to see the next vid!
By far my favourite and most inspiring channel on RUclips!
I would like to see the deathtrap on that dyno again at the start of a video so we can see the power it makes as a reference, I feel like this has taken a big step back from the early days of the brute force concept engine, that with the single rotary valve seemed like the best version in my opinion
Always enjoyable to watch whether up or down, winning or not quite winning. These videos give me encouragement to persevere with my own projects when things don't go well.
What make me come back to your channel isn't the fact that you fail, it's the fact that you keep trying.
Sir you are an artist, a thinker and a doer. Cheers to us all
It was hard seeing you so beat down, luckily you found a way back. A true roller coaster as somebody else posted! Keep up the good work and never change!
I had this Koiritz twin two stoke engine made in 1976 apart and was looking at the intake transfer ports and the angle at which they shot mixture into the cylinder. The left and right A intake ports were the widest ports (about 3-4 times wider than the B and C ports) and would push air towards the backside of the engine away from the exhaust port while the B and C ports which were about the same width looked like they would help move the mixture upwards into the top of the cylinder and help tumble the mixture coming from the A transfer ports. This engine ran without a pipe on it. When I was looking at this old engines conservative design (55hp from 440cc) I was thinking about your radical port areas and how much you rely on exhaust pulses to keep the mixture in the cylinder. Neat to see this idea of port direction and size being explored again.
progress in the right direction now, I AM HYPED FOR NEXT EPISODE!!!
23:10 - your face says it all. The suspense builds once again. Your videos are so enjoyable to watch, thanks for another quality episode. See you next time!!
Great job Alex. This is a breakthrough moment. The salt flats are calling.
Cheers from Morrison, Colorado.
17:58 Sometimes, this is how I feel waiting for these videos... Please keep up the good work!
Your videos are not only entertaining but also very educative, I've learned a lot from you!
Trial and terror!!! There isn't any other way 😂 Super action packed episode 🤙 Love your drive and stamina, we're cut from the same cloth 😜 my 71 x 62 241cc took me over 10 years of struggle. It's worth it in the end, I jump on it, and it rides like a factory bike on steroids @12,500 rpm. I really don't want to have to pull it down anymore tho 😂
Keep up the perseverance! You will succeed!
it's so nice to see that little smirk back on your face again mate that's the spark the little ember back there flaring back up for the first time in months
Great episode, sounds so much happier after the port opened up.
A useful stepped edge is a useful step
I have gotten very bored of RUclips. But this channel always keeps me at the edge of my seat. Awesome job man!
22:25 many four stroke exhaust headers use the step feature, its called an anti-reversion step.
In the intake duct works an inward-contraction duct, and the exhaust duct acts as an outwardly expanding duct. Hopefully Google translate made a sensible translation, this too needed to be corrected.
Im so happy to see this revent breakthrough ive been following this channel for 5+years and the journey has been wild
Would like to see a road test to see what it does off the dyno.
Your exhaust port may have equivalent area to your port area, but due to that extremely thin oval shape, it will be *effectively* much smaller because of the boundary layer of air that forms where moving air touches a stationary surface. For some reading on the subject, you can look at things written about the flow of oval-shaped exhaust vs circular. An oval shaped exhaust of equivalent area to a circle will flow less, because more of it is in the turbulent boundary flow area.
I have limited 2 stroke experience, but in 4 stroke engines the optimal exhaust port shape is like a D, but with the flat part on the bottom and the curved part facing up. Porting the bottom of your exhaust port so that it is flat, and the top is the original oval shape, would probably significantly improve exhaust flow. I see you came to a similar conclusion on your own in the latter half of the video, but I wanted to try and explain some of the mechanics behind that in case it might help you later. In 4 strokes at least, the step going from the exhaust to the port is generally a positive thing. There are even headers that have an additional step-up in size. If you can with CFD, maybe calculating the area of your cylinder ports minus their boundary layer, and making that equivalent to the exhaust port minus the boundary layer?
You deserve the positive results man, and I'm happy to see it. As a viewer though, the journey is just as interesting as the destination. Is it just me, or does it sound cooler with the big exhaust port?
yup, this! Maybe Alex can do some 3D steady-state exhaust port sims (based on exhaust port delta pressure) to see that boundary effect impact on flow rate. And then adjust the port until it gets closer to the 1D sim flow rate.
i love my fridays coming home after a long day and watching you videos has been apart of my rotine for a long time now
You are my favorite creator. I enjoy every single video you post. Your camera angles and video quality are the best no one touches your style buddy please continue doing what you're doing. Congratulations 🎉🎉🎉
Opps...too much coffee...article is a year old...lol...but good summary...
Alex, you are on your way
I like to cheer you on in Utah when you return. I lived in SLC 1981-1983...my bikes at the tine 1979 IT-400 and 1970 Yamaha 350 R5...buddy drove new Husky 1982 430 WR....then broke his leg...
I kept up but the Husky was faster. We rode once towards the flats...lots of wide open area to get the wick up and all the way open.
Once I went to Draper...thru the back way...too cheap too pay...went to the top to witness Widow Maker hillclimb. Two made it over in 2 hours...
How did I get the bike there ?...I hauled using a 1965 VW Bug...powered with my built 1835....another story...lol.
The bike was strapped to the rear bumper.
In that VW, no one could pass me going up Parley summit hill on i-80...lol
This will be the end of my rambling...
It's all good
I think you need to do one of two things. Adapt the aprilia cases, that you engine is coupled to, to verify your cylinder, or, put a known good cylinder onto you cases. This way you will know where to start looking
I’ve said it before and I’ll say it again- my favourite RUclips channel.
Keep at it. I dont mind the results or making a ton of power. I just like the fact that you try new things with 2 strokes when no one else is
The only thing that I can think of is maybe a clear coat of the pla stuffers. At high rpms, it may be pulling air right through the print. I do some printing, and it is usually not waterproof.
My heart sank when you started running the engine after the transfer channel mod. But seeing the increase in HP after the exhaust mod im happy you got some part of the smoking gun.
I love this channel for the exploration/ trial and error! Keep it up!
How about adding a simple wideband lambda to see how the engine is running? This would give you a great insight into how the fuelling system is setup
Your air compressor was trying to to tell you something... make power and make it loud, not compressed air coming out of a small port. Please keep the videos coming, love them, Cheers.
Btw , pulse fronts prefer round to mild oval shapes ,not flat oval shapes!
Should have gone with a malossi mhr, geometry is on point on these cylinder. BUT the suffering is more interesting, the way you try to improve your part is really inspiring.
what about Bidalot RF 50 ? seems to have pretty impressive numbers, don't know the differences though
@@geemy9675 The RF50WR competition is just the best on the market, but you have to use every Bidalot hyper sport part for the best result, the adaptable one is the best to throw on a stock crackshaft and will accept many parts and tune with no hiccups, but in my opinion, and knowing personnaly mr Bidalot, i won't use them to experiment, just to have something that will do exactly what i ask them to do.
Great video. Amazing actually. Great wrk. Always enjoy watching
Thanks man!
How about a plexiglass cylinder head and a smoke machine to blow smoke through the crankcase so you can visualise how the ports are directing flow?
even water can be used out of a faucet (for just the cylinder though)
I always used the varsol tank. To check port roof angle I needed to clean the filings out anyway. Gave me a good visualization
A blow lamp flame pointed down the port duct gives a very good indication of gas flow.
@17:28 ish. It looks like the connection between the engine and the exhaust pipe is leaking some exhaust and spraying something
Slight exhaust leak, added an oring at the end of the vid. There's a slight water leak where the hose connects to the head, occasional droplets hits the header.
Ok, that makes sense. I was worried the pipe wasn't working with the right resonance causing the pressure to build and push out where it wasn't supposed to.
So hard to see you struggling trying so hard for your ideas. Keep going my friend the solution may seem impossible but your engineering logic will prevail. Nobody's tried harder than you. Everybody who follows your site wants you to succeed
Take care matey look forward to success if anybody deserves a victory its you
Arthur
"I'm almost 100% sure this will solve our problems.." I love your optimism 😜
From an aerodynamic point of view, the "hook" doesn't do shit. It creates a stagnation zone, and the gas continues on in the mean direction of the port anyway...
Lekker to see you emerging from under the desk and getting some promising results!!!!
Sounding much better than the last time. You will work it out. 👌🏼👍🏼👍🏼👍🏼🤙🤞
I love your efforts and showing these lessons. The velocity of air at a port wall surface is zero and increases exponentially away from the port surface. Its the boundary layer effect. You have on those wide skinny ports an overlapping boundary layer with near zero velocity for much of your port cross section. So what I'm saying is you want the most cross sectional area with the least amount of port surface area. Perfect circle my friend.
Definitely need to revisit the exhaust. For any 2-stroke engine that you want to run at very high RPM, the pipe diameter should increase into the expansion chamber at a slower rate than the decrease back to a smaller diameter happens.
This is especially important with this engine, since the piston vs crankcase volume ratio and compression ratios are both expected to be much larger than typical.
The wild thing about you trying absolutely everything is that you could eventually fix issues no one knew existed.
Nice to see and hear PiP doing so well. The only thing I have left over from my engine tragedy is the 28mm carb which has larger power jet fitted made from a 5mm round jet. This ran very well, I even fitted a large pilot jet which I used as a fine fuel control at high RPM. If you want it and want to use it, it's yours.
I fully understand your sentiment re not just wanting to tune a standard engine.
Please, tell me what this music is you used.
PS, it's the old adage. You have to get it out quicker than you put it in.
PPS, would you ever consider blocking the B port ducts with toilet paper and just try running it on the A ports.
Your getting there!
Good to see a smile at the end.
I really liked this episode! At least you are willing to re-examine your theories.
Your reaction at 23:10 is just amazing to watch, it seems small, but man that gives hope!
The aspect ratio will also be a factor in what the effective cross sectional area will be... Certainly looking better with the new shape.
Getting the spent gas out is key too making power in the 2 stroke. Limit the variables. Good show I think you have it connered now.
It's the old adage. You've got to get it out quicker than you put it in!
Great show been seeing all of them mit check a carb you mit like its calleda smart carb sc2 thats what its called have fun great work thank you...
Another thought.
Barrier gases on exhaust duct due to narrow height.
Turbulence near walls so you get Eddie currents on narrow passages, so even if it was 100% of exhaust port it wouldn't flow like a round channel.
Yes exhaust
This video was epic and brought joy for me. Thank you for this video!
The step in the exhaust on return of spent gasses won't let you take advantage of the exhaust pulling the intake charge out and then stuffing it back in before the piston closes the port.
It's a simple job to mould exhaust paste to make a nice transition but at 16000 it didn't last long in my test engine but proved a point and dirt cheap.
Your my 2stroke hero!!!!! Thank you
Here's my theory.
There's a reason exhaust ports are not normally so flat. The walls of the port create turbulence within a certain distance of them as the exhaust gasses try to cling to them. It's caused by the friction of the gasses as they flow down the port. The further you get from the wall, the less turbulence there is. So if your port is quite flat like yours was, there's more turbulence almost everywhere in the port compared to a rounder shape.
Hello Chris. The shape of this exhaust port came from the desire to run a 100% of bore exhaust which sadly failed. A bridge was later welded in to allow the cylinder to be used.
The gentlemen that mentioned the use of an see through cylinder head is got a good point, because if you can adjust the actual flow pattern, and see how much it changes the power curve.
Then adjustable vanes in the intake that allow you to curve the airstream to the optimal position to increase the flame kernels to work to your advantage.
This would also give you a better idea of optimal position for the spark plug location in the cylinder head itself.
Also you can actually play with different designs for the combustion chambers like they do with cylinder heads on automotive designs.
Such as the hemispheric head used by Dodge, are different designs by the other engine programs like Honda indi engines, the options are unlimited by examining many different types of combustion chambers, because although the two cycle engines are unique in a way, but there's been so many different changes over the last few decades that unless you try to open your mind's eye to all the different manufacturers designs your trapped in a never ending circle chasing your tails
Peak horsepower was about negative 8. Progress! Also I really liked the music here. Felt like watching the first pirates of the Caribbean movie. I kept waiting for Kira Knightly to pop out but no such luck.
Yes! This must be what held back the extra-filled cylinder of the blower arrangement.
I'll keep watching, no matter what
I don't know how you keep going I watch every week hoping for a brake through your stress levels must be ridiculous 😅keep going I want the supercharger back
I love all the fun and nonstandard stuff you do dont give up on your non bog standard way of doing things that is where true advancement and true boundary pushing resides at
Ok , after watching the whole video I'm getting frustrated 😂😂. On a 2 stroke you cannot use different port timings and exhaust layouts without altering the expansion chamber pipe design. They all work together ! I have a feeling that your throwing stones in the bush hoping to find the silver bullet. Go back to basics ! You have the best simulation program in the world ! Use it and you will get amazing results 😉😉 Hint is Vannik 😁😁
The Transfer ports are similar to Aprilia RSA 125 , keep going man❤❤
New name for the channel "2 Stroke Suffering" 😁😁😁
Dont know too much about 2 strokes but about 1:50 at the video you are explaining the transfer ports, yours vs the convetional one, there is differenrence (if I was able to follow). The hook design will decelerate the flow and increase the pressure at the exit area. Your desing is doing the opposite as the port narrows down at the exit area. Intuitively you would like to have low velocity and high pressure flow entering to cylinder, not vice versa. This might have something to do with the power out put.
and off we go down another rabbithole of enlightenment,,,,ace.
The angry wasp is starting to scream. Soon we will all want one!
Very entertaining dude. Keep chipping away with this setup and you will get there buddy. Big jumps in direction is causing too many grey areas I feel.
And now try it with the weird angle porting just for the information. Big exhaust, you only have so little time to scavenge the cylinder. Then play with the pipe to stuff the excess back and see power!
Keep the faith. You are closer to solution than you think.
love this channel. You learn something new every video
The under desk retreat cracked me up... "I'm just going to lay here now and wait for the sweet release of death" 😂