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Hi, I'm pleased you are enjoying the content and have subscribed cheers. There will be more to come :) Yes, the Blair research really helped out to get to a good point quickly. The simulators and calculators I use are mainly based on his and his colleagues research at QUB. I spent a lot of time in the virtual tuning world so now this project is a chance to get into real world tuning of two strokes. cheers

Yah, I think a lot of 16 year olds didn't know how to look after their bikes! My first bike was a Honda MT 50, and yes it was pretty slow... slower than my mates AR 50 anyway... which is why I got one

Cool, I assumed he was born in the UK. There is a lot of interesting stuff on his channel. Although 4 stroke I feel some of it applies to 2 strokes too.

Hi, I'm not sure tbh. Disk valves, in theory, are better for max power as they offer no resistance when open but have fixed timing. Reed valves allow variable timing that's dictated by the engine itself.

@@AutoBeta2T oh thanks for the information

Defiently! Maybe someday 🙃

Cool, I'm pleased this has helped. Let me know how get on? Regards Dave 😊

Hi, I think it would struggle at that rpm. Being over square reduces the port area available for given port timings.

97 cc, about 11.5k rpm

@@AutoBeta2T Mopeed???? Stroke mm? bore mm?

54.5mm bore. Stroke 41.6mm

@@AutoBeta2T Short stroke. Need more rpm. Only the top intrake valve???

I should make enough power 😃

Sweet, that's pretty cool AI is recommending me :) I'm pleased you enjoyed it. I've done a few more pipe videos. In this one, I play with the length of the dwell and header a bit. th-cam.com/video/yZXhKxrykCc/w-d-xo.htmlsi=QIQv7JIDjYsvVvF_ I should really do another and focus on the changes to the curve from length changes. It certainly does make a difference.

Top Tip! Did it release okay?

@@AutoBeta2T No problem most of the time, a couple got stuck tho, forgot to cut the earth electrode off the spark plug and pack it with plasticine 😆 I found it best to pour it in stages for large combustion chambers, sometimes filling the whole thing it shrinks. No use for transfers tho, that silicon stuff you're using is prolly the only thing you'll get out of those. Edit Obviously the wax is harder to cut in half as well.

I heard they had one of these to 100mph!

Hi, I'm pleased you are enjoying the videos. In your adjustments is it usually to the rear of the cylinder you adjust the flow? I want to do some tests with different transfer angles.

@@AutoBeta2T I make small changes to the transfers, directing the transfer flow backwards until I find symmetry in the flow at the piston crown. Most of the engines I work with are Av10 72.5cc, they only have 2 side transfers and one rear.

Cool, thank you for sharing 😊

Hi, me too. It could make for an interesting test. I'll add it to the list 😁

I loved my AR93 when I was 16, too. Like you say, there wasn't a lot of information around then. No Internet or anything. How did we manage? It sounds like the algorithm has figured cover the same subject as Alex and is pointing people this way. Thanks for the comment, and I'm pleased you are enjoying 😀

No problems, cheers for watching 😄

Yes, you could. I did some tests on my race bike some years ago with the stinger and smaller did give more power. However, I got greedy and melted the motor. The ignitech would be able to control what you suggest. I was thinking water injection but a variable stinger restriction should work similar.

Yeah, it's such a short time. I'm not sure of the rpm that I did the tests at but 1000 to 1500 max... so, really low but I guess a clue to what may be going on?

Yes, it was. I'd like to do some more research into this at some point and certainly into flow inside the two-stroke engine. It's such a simple design, but so complex too. Yes, an angle of attack greater than about that, and the airofoil will start to stall. Maybe filling the lower exhaust duct is helping to keep the flow attached to the front face of the piston better?

Good point.

Yep, that would be cool 😎

Yes, it's quite low rpm and no resonance effect from the exhaust and the intake... I wonder if a clear head could be made? I could do with better slow motion, too and better contrast between the smoke and the engine. And a more powerful drill to get the rpm higher. Cheers, and hopefully, we can come up with something better to visualise the chaos inside the two stroke 😊

​@@AutoBeta2Tможет быть будет полезен опыт этих парней: th-cam.com/video/liBRL6Hov-Y/w-d-xo.htmlsi=BBBA8pxZymlUqR_0

Thanks for the link. I had seen this before - it really needs a super slow-motion camera the it would be really cool. This clear head looks good. th-cam.com/video/45J5WnXtntQ/w-d-xo.htmlsi=MYEDJiDtS09-Y87k

Hi Roy, Yes, it certainly does, which is good. I actually started to observe the emulsion of the 2t oil and the moisture from the smoke I was using, forming on the crown of the piston similar to what I've seen where the cooling wash of the transfers has stopped charing of the oil on the hot piston surface. I'm assuming this it what you have observed, too?

​@@AutoBeta2TYou said it better tho 😂

😁 Note - minor edit for my fat fingers 👉

@@AutoBeta2T Hi again Dave, just had an idea, if you have used piston with the flow pattern compare it with the smoke stain you saw on the test one. Edit See if the angle looks the same or just similar

@@AutoBeta2T what I was thinking about with comparing the flow marks on the pistons, when the engine is running the air will be coming thru the port windows much faster and prolly won't diffuse as much as maybe the smoke test so if you're planning to re direct them you'll need to know what discrepancy you'll get between test results and a running engine. Could hardly think straight last night, had a crap day and my head was still spinning round in the "hamster wheel" 😆

Hi Henrik, I was thinking the same. Even without the head, I saw some footage of the smoke going out of the exhaust, but like you say, a clear head should steer it better. I wish I could have got some super slow motion, but it records such a small amount I kept missing the money shot. Yeah. It gets quite foggy quickly, and with no suction from the exhaust, it soon builds up.

Hi Patrick, Thanks again for the inspiration. I tried with my fingers, and I could feel the direction of the flow, as you said. To note, I was getting a buildup on the piston crown of the 2 t oil and water (from the smoke) emulsion whre you tend to get the cool spots from the transfer flow in a actual engine.

Hi Cliff, welcome to the channel 😀 Yep, as you say, what I am doing here is not representative of the unsteady gas flow in two strokes, but hopefully, it gives a few pointers to what could help performance? I don't think even high-end CFD can fully model the chaotic events inside the engine. All good fun, though :) Cheers for watching Dave :)

Hi, cheers, and I'm pleased you are enjoying the videos. The ports are already fairly maxed out from standard but still have some more to go, I think - that will come. Next up is compression, but I plan to go lower first as more energy in the pipe in theory should help... but if that doesn't work, then I'll look to increase it higher. I want to do the 100mph on pump fuel, which is 97 - 99 octane as per the original chalenge but until I can do some real world runs I won't know if I can get away with it.

@@AutoBeta2T Understood with the challenge. I have only picked this up somewhere in the middle so wasn't aware. Back in the day I started out with a GP100, disk valve and all lol. Shall watch with interest 👍

@@CATANOVA cool, enjoy 😁

Me too John, it was mostly the same for me with learning how to make pipes. I did get some help from a mate in Oz but learing to weld and how to make pipes at the same time took plenty of goes. My first few pipes had so many holes in them as I struggled to get the cone faces flat and then played the game of trying to fill them before burning an even bigger hole into it. Yes, it was great spending the day watching Mick. He has so many tips and tricks to make pipes easier and it was great of him to share them with all of us. A top bloke 😄

@@AutoBeta2T I have just picked up a full oxy acetylene welding kit from the merchants today. Have not used one since I was in school metal work lol. Let see if I can make a pipe lol.

@john63397 should be interesting to see how you get on. From what I could see gas welding seemed to be more forgiving and quicker than tig. Saying that Mick has many years of practice.

@@AutoBeta2T OK, I'm back for another look at the gas welding lol. I am having reasonable results. Main issues are popping/blowing holes and deformation. I am using 1.2mm mig wire as filler , this may be causing problems. Also Mick is using a much more aggressive flame and moving quicker. But yeah, gas welding could be the way to go for faster pipe building and testing. Its got potential.

@john63397 cool, sounds like fun. Mick did mention that you had to use the proper gas welding rods... something about carbon, I think?

Hi, I'm not that up on 4Ts but I know they do a lot of flow testing with them, but Dr Gordon Blair did use Time Area for 4 stoke development as I remember ? He did an article called: back to basics but I can't seem to fi d the link to it now?

@@AutoBeta2T not sure, it just made sense, I'm building a flowbench myself.

Cool - that will be really when you get it done.

@@AutoBeta2T yup annoying part is programming on my budget....

Is there some off the shelf flowbench software? I think performance trends does one?

Hi Bryan, cheers and noted I need to get my finger out 😆 I had a real busy year last year with my dad being ill, and after he passed, I've struggled to get back into it, but I am getting there... Life's busy with checking on my mum and having two kids with hobbies/sports that take out most weekends... I am on it, though, and I want to get a base gearing set-up and the bike MOTed for a road shakedown to test jetting and ign timing under real world load conditions.

@@AutoBeta2T hey sorry to hear about your father. My father's 90 I'm here with him. Lost mom back in 2015 staid with her till the end now same story with dad. Finally we got out of the nhra prostock motorcycle racing. Hopefully not gonna build as many of them. Glad to see you tinkering on vid .

@2strokecarbtuningportingin187 cheers buddy 😊

Hi 👋

But that part of MOTA simulating gas direction is interesting, i might need to upgrade =)

So the 2d sim isn't in Mota X?

@@AutoBeta2T no :( I don´t think so, but i also have Mota 7 i just noticed, i might check that up some more =)

@@AutoBeta2T Man,, i can´t even start mota 7. 'run time error'... =(

@@AutoBeta2T I got it running,, changed the screenresolution. New toys to play with =)

Cheers Joshua

Cheers 😃

Sounds like a cool engine 😎

@@AutoBeta2T yeah hot and cold, yes and no, lol

Hi, I'm not sure if it could be used on 4 strokes? The software wouldn't, but I guess the pressure readings on the manometers could be used to show a change in flow. The manometers are measuring pressure at the entry to the venturi and the delta between the entry and the throat. The software used this data along with anbient pressure and temperature to work out the flow time.area. So it should be calculating mass flow at each piston opening I believe?

Not sure exactly what your question is but you measure flow rate at different valve lift rates. Meaning on a flow bench. Build prostock nhra engines. But never tested with piston in different locations don't know how you would do that typically the flow bench is sucking from where the piston is located

Cheers Darren 😃

Cheers for the tips. I've had that printer for some time now but I've never delved into setting it up properly. Something to do for next time.

@@AutoBeta2T i suggest you do the cheaters route i call it. 1. make a square in the slicer and have it be hollow with one wall an no roof. 2. copy this "cup" and paste it four times so u have 5 of them. set each one to 0.1 incremental steps of flow in the slicer. 3. print and measure thickness of walls and divide by four for each of the 5 "cups" EDIT : label them with the text tool so they dont get mixed up after the print. 3 the one that you have the closest value to is ur set target for fine tuning :) 4.fine tuning is repeat process until satisfaction. some get thrown off by their zoffset squishing the first layer so much that the nozzle digs into the laid down material causing the filament to be moved to the sides in every layer. so when the next layer comes the nozzle does not have space to extrude in the correct place forcing the material to path of least resistance. this can look like overextrusion but its most likely both. this is creating this cumulative effect of distortions to finish and model. i suspect you get quite a lot of strings after travels and that your hotend get a bit dirty as well? its quite the easy job and will take you one or two goes to be happy enough to reply to this comment when its done and ur prints look pretty :) i do some 2stroke fun as well and i gotta say that it was clever to use the vac. kudos on the idea. im gonna steal that one :P back to porting the chainsaws puny 37.5cc !

Cheers Duggers, it is a bit out there but something I needed to do. Some back to back cylinder head tests next so less theory and more practical 😃

Two stokes are part technology and part witchcraft, the technology points you in the right direction then after that, , , , If you want them I can send some vids I made for an Internet friend for drawing out expansion chambers old school, no computers, no printouts, just a school geometry set, tape measure and a strip of cardboard, It's prolly how Walter Kaden made the MZ ones in the 50s or 60s, not accurate enough to chase the last half of a horsepower but more than adequate for improving your street bike. Assuming you can calculate the pipe length and cone tapers in the first place. You'll find that in the books Dave mentioned.

Thanks ✌