Preheating to a certain degree helps atomization occur faster if you only use coolant or exhaust heat to preheat just to a certain temperature. You could also use self-lubricated ceramic parts for the pumping aspects of the injection system, if you can make an affordable option.
Take a look at the Evinrude/Rotax E-tec direct injection system. A quite simple system with a electric powered coil and a ram that both works as a pump and a injector. czcams.com/video/daN72ij2eTU/video.htmlm20s
Good video that hakan Bjorkman. Perfect example of development and why 2t are far from obsolete. (or shite). Ja sam - are you trying to say 500psi is not enough? Even though it works and is in production right now?
+Ja sam I guess you where pointing out the difference between the figures claimed necessary in the video and the real world figures then? Apologies, and I`m glad I`m not he only one that noticed..
Suzuki X7 with direct injection and a sidecar to house the pump! Seriously though often wondered why there hasn't been a revival of 2 stroke engines with DI. thanks
Curious about the Bimota V-DUE 500... How did they work? I heard they had separate/sealed crankcases like a 4t??? and passed emissions in 98, I know they had some problems (although later fixed with kits) do to Bimota pushing them out the door too fast, killing the company and a possible 2t revolution with it. I just have no Idea how they worked.
6:40 a gasoline engine might have compression ratio around 10:1 (just a coefficient nubmer) BUT the pressure at TDC will be greater due to an air compression heating (dynamic compression ratio or something like this) and this could be around 13-15 atmospheres (pressure measurement).
I think looking to marine applications, provides some other examples were they are common place. The complicated/heavy/high pressures etcetera direct injection issues have been solved with lower revving 5-6K and bigger disc placements1.7L- 3.5L. I think a review of new Evinrude ETec/ G2 engines may contribute to your analysis. The high tech management systems seem to have played a significant part also. Efficiencies were solved and torque was supreme in this sector for the last 3-5 years. (Looking at the Evinrude 2 stroke vs the Yamaha 4 stroke in the 300hp range - 2 stroke shows a reduction in weight of about 10% and a 10% decrease in displacement, this was were fuel and exhaust was managed into Eco friendly shifts in thinking. I hope to see road bikes again return with 2 stroke power but the above parameters may be too large at present but we hold out for electronic fuel pumps and other such components to reduce in size to perhaps fix all of this.
Loved the EXP2's Activated Radical Combustion system. Honda claimed this system was very fuel efficient, was an improvement in driveability and clean. A dirtbike and a scooter were introduced with this technology. Then Honda went 4 stroke minded or something, because after 2000 everything went 4 stroke (including motorsport). I hope something will save the 2 stroke, injection systems are a good step in that direction.
As you said in the camless engine video, technology and materiels need to get to a stage where it becomes practical/necessary and cost effective. Until regulation, there was no need to further refine 2t but now they have to become cleaner they will begin to make use of new ideas and the problems will be overcome, just like 4t had/has to.
Competition in the same class where major design deviations are not allowed. Further more the bikes could already produce more power than could be safely restrained so developing and complicating it more was unnecessary, until regulation intervened of course.
Yeah, thats for diesels, which due to their higher compression ratios need even more pressure to over come the pressure in the cylinder. Not only that but because they are compression ignition the fuel starts to burn increasing the pressure before the injector has finished firing, hence even more pressure required. For GDI they don't need to go as high as the injector will close before the ignition fires - matt
Do a supercharged Direct Injection 2-stroke with oiling system! 👍🏻 I bet the power output and efficiency would be incredible. We need a vid on it and possibly with more than a single cylinder would really be a game changer. It might be the rebirth of 2-stroke
Sorry, I meant turbocharger. Which part, the efficiency, or the power output, or both? I mean, you're not blowing the unburnt fuel out the muffler with direct injection. Plus, whatever turbo pressure makes it past compression will go back into spinning the turbo, at least somewhat. No exhausting stroke needed. I guess it could depend on just how fast your 2-stroker can rev up to as well without failure.
It would require a new type of fuel pump but that is totally possible, just has not been done yet. You can have an eccentric, camlike surface for a rotor over a stator who force output is very high during points of maximum mechanical advantage. As one example. Because you would most likely be talking about single-cylinder engines for bikes, generators, etc.. it could be cost-effective.
in the earley 2000's evenrude had made a new outboard direct injected 2 stroke that was supposed to be better with fuel economy than an equivelent 4 stroke
very true but the BRP engines are really complicated, expensive and quite large. Take the specs from a Evinrude 115 - 1.7 litre V4 and produced 115 HP?! and it weighed 166kgs! An R6 is 190Kgs fully fuelled and ready to go, makes 122Hp and is only a 600cc. Are you gonna say that the Evinrude 115 has better fuel economy than the R6?
Simple answer to all this, Matt. Direct injection makes more sense on bigger engines. So ... 1000cc two stroke motorcycles are the best option. Make it so! :)
Gasoline direct injection is becoming the norm on new cars and even economy cars. The high pressure pumps are typically smaller than a fist and don't require special lubrication. They could easily be used on a motorcycle engine. Horsepower goes up and fuel consumption goes down which is why it's now in wide use despite slightly higher costs. On a direct injection 2 stroke, however, you would need to lubricate the crankcase.
How about a two stroke fuel injected motor that works with a supercharger like a diesel but uses a spark plug and gasoline? The crankcase wouldn't be part of the cycle...
Certain snowmobiles, namely Polaris sleds, had both oil injection and fuel injection starting in the late 1980's and early 1990's. It is the Japanese manufacturers fault alone that they did not adopt this, despite the fact it's been around and in full use for near 30 years.
I know this is an old video but some of your facts are off a bit. Yamaha was the first to offer oil injection as far back on production snowmobiles as 1969. Yamaha also offered fuel injection in 1977 or so on the race sleds. Arctic cat was the first to offer fuel injection on production sleds and polaris was second though not by much. Polaris had to stop making fuel injected sleds ( short lived and only 2 models ) because they ripped off the original design from the automotive world so were sued. At that time both Arctic and Polaris used Japanese engines ( arctic cat = Suzuki and polaris = Fuji heavy industries) so I dont think it was the Japanese who stopped 2 strokes from developing fuel injection.
the point of two stroke lubricating the entire engine with one source of lube. dfi has complicated it to much lublin the parts that with different systems to oil big end rod an crank bearings. they more work R&D to do.
what if you had longer than normal stroke and the the exhaust port was moved closer to BDC and combustion happened just as the exhaust port closed? Obviously this would decrease pressure... Right? If so how significant would the decrease be?
The latest one is the E-TEC 850 - czcams.com/video/jo-r7LwI70Q/video.html Great engine, but my god it must cost alot. In the video the guy states that - "with a forged crankshaft and oil feed just like a 4 stroke, for reliability" - my point exactly lol
Pressurise your fuel reservoir. Required - Petrol tank, petrol, foot pump, pet elephant. ( I think an Elephant can exert a foot force of 2000 bar. If not train it to jump up and down) Easy.
Yes simple answer, did my uni dissatation on it (92% i got on it :P). Was suprised how many uni profs wanted to read it. Lighter, more power to weight, list goes on . The only thing that let the concept down was the short circuiting of unburnt fuel and oil. Inject the fuel in when the ports are shut and add cleaner burning oils there you go. KTM are planning on releasing a new two stroke with this technology.
@Luca Mont Hi, i found the soft bound copy but soft copy i did not. However now you have reminded me again will have a look on my old laptop this weekend :)
Hello mate, this is Doru from Romania, I had an ideea and I thought I should take a second opinion, especially I've seen a lot of your videos from this 2 stroke DFI series and you're good, my question is why not to put a low pressure fuel injector exactly under the exhaust port, and time it to spray in the opposite direction of the intake port in the intake stroke ? I thought that because of the crossing of the atomized fuel and air the mixture will be more refined and the thermal efficiency will be better, and because of the pressure of the atomized fuel, the mixture will be thrown in the opposite corner of the cilinder, considering the exhaust port, and hopefully the engine speed will close the exhaust port before any of the mixture can escape the cilinder, hope to hear you're opinion, have a good one 🙂(PS :I'll work on a 3D model, if you're interested)
does that not mean with dfi the port positions can drastically be changed to almost perpendicular positions? could the crank then be sealed to run in oil for lubrication, with a cylinder inlet port?, or would the crank still need to be used as a pump?.. suppose that is a 2-stroke diesel engine lol.
You are right on most of things, but your fuel pressure values are awfully wrong here. As piaggio (aprilia) in early 2000's made direct injected 2 50cc stroke scooter and it used air assisted direct injection after closing exhaust port with max air pressure of only 8bars. Called DiTech. Look it up. Ecu Rev limit was 10000rpm. Had one.
"but your fuel pressure values are awfully wrong here" Come on dude, if you're going to call someone out get it right. The DiTech (morini system) and/or the Purejet (piaggio system) is in theory a direct injection system but in the same way the TPI system is on the KTM. The injector spray fuel into the cylinder just as the exhaust port closes not like the Etec system or at TDC like diesel systems. They were soooo good that they're no longer used.
@@dirtygarageguy Your responses do not need to be rude in order for you to reply. To quote you in this video: "As soon as you close your exhaust port you can spray fuel. The problem is that then piston is very close to TDC and that the pressure is quite high ~ 8-12 bar." Which is incorrect. And you're trying to avoid the fact by trash talking about the system itself. Direct injection is every injection that has injector located in cylinder head and sprays directly into combustion chamber, no matter the timing of injection itself. I didnt say that DiTech was perfect in any way, as it was a first attempt at that technology. But it did what it was advertised for.
"The problem is that then piston is very close to TDC and that the pressure is quite high ~ 8-12 bar."" - yeah, very close to TDC the pressure is between 8 to 12 bar. Have you ever done a compression test? "Which is incorrect." - do a compression test and get back to me. "Direct injection is every injection that has injector located in cylinder head and sprays directly into combustion chamber, no matter the timing of injection itself." - Very true - not arguing that, however when an injector fires is very important when concerned with fuel pressure. "But it did what it was advertised for." - What did it advertise?
@@dirtygarageguy Read what you said again, its "then", not "when". Changes the meaning of sentence. It makes sense to inject as soon as exhaust port closes as it gets the unwanted 2 stroke wasted fuel flaw sorted out. Only thing why would you inject at TDC is stratospheric lean burn, which you don't need to use. Its not a diesel that you need to inject at tdc in order to get the mixture ignited, you have a sparkplug there to do the job. P.S. all the injection problems that you describe here have actually been sorted out, but not for two strokes but your beloved 4 strokes (Audi/VAG TFSI) and they work very well so no point in discussing that problem as the solution is already there. DiTech was advertised as "new" technology, better power/torque than same 2stroke carbed models (and 4stroke) and better emissions and fuel economy than both conventional 2 or 4 stroke engine. Never advertised as reliable. (damn Italians)
Matt, do you think someone will succeed in doing Direct High Pressure Fi on 2 strokes in a few years ? Or will they abandon the IC engine all together and go electric dildo on wheels route ?
That's what I would like to know to. And maybe there could be a way to reduce the emissions from the oil scraped off at the exhaust port. I really hope 2 strokes don't die.
@@EbonyPope They are already dead as far as I am concerned. But I love them and ride one! Plus people want to ban Diesels which are cleaner than even the cleanest 2 strokes :/
Why does my 300cc 2 stroke only have a compression of 6.9:1? Can you explain why they chose to go so low and what benefits and why/how increasing the compression (and to how high) would have? :D thanks great videos!
The biggest problem with 2 stroke is the ethanol in gasoline. When ethanol sits for even a week it absorbs air moisture and washes out the oil; overheats the piston and case. I just bought 1 gallon of Stihl motomix for my chainsaw and it was $34.99 US.
"When ethanol/gas sits for even a week it absorbs air moisture and washes out the oil its mixed with;" - LOL you do realise that petrol/gasoline is a solvnet for oil, not water. Water and oil don't mix LOL - and i've done a video about how much ethanol absorbs water, and after 3 months its not that much at all. One other problem with what you just said. Gasoline is what cools engines and your piston, not the oil. Oil is there to reduce friction.
The Workshop- on a side note, I have a 1981 ATC 250R with a steel sleeve. I had it bored 2mm over. With a larger carburetor will it make more power? Do I need to change the mix? It’s 20:1 now stock
"Ethanol is hygroscopic meaning it absorbs water and does so 50 times it’s mass." BRAHAHAHAH! Are you fucking insane, just think about what you have written for 1 second. That means that if you has 1 litre of ethanol it absorbs 50 litres. How the fuck and where the fuck does all that water come from? LOL You do realise that water weighs 1 kg per litre. Ethanol is hygroscopic, and over 3 months tested samples of E10 absorbed 3% water of the ethanols mass - which was 50g of ethanol. 3 MONTHS! Do you understand how dry air is? "The Workshop- on a side note, I have a 1981 ATC 250R with a steel sleeve. I had it bored 2mm over. With a larger carburetor will it make more power? Do I need to change the mix? It’s 20:1 now stock" - 2mm increases your dispalcement from 246cc to 261cc - that's a 6% increase, so no, you'll be fine. And no, the premix is based on fuel volume - you draw in 6% more fuel then 1/20th of that will be oil
I didn't realize this was an option or ongoing project for the two stroke world... I started riding 4strokes about ten years ago and haven't seen a need for anything else since. although I do sometimes rebuild two strokes for friends that still prefer whining over the power of modern technology.
One distinct advantage of 2-strokes that ensures they aren't going away any time soon is no crankcase oil. why? It can run upside-down. this is one advantage I haven't heard you say yet. the only real replacement is the electric chainsaw.
when the exhaust port closes what is the cylinder pressure? I doubt it could be much more than 2 bar. If the compression ratio of a two stroke is 10:1 geometric, than once the exhaust port closes the the compression ratio could not be much more than 5:1. I noticed no discussion of the orbital air assisted fuel injection. I am sure you must be aware of them. Have you looked at the retrofitting by Envirofit of 2 strokes in the Philippines? 1 cylinder 100 cc taxi motors were retrofitted with an Orbital based air assist for less than $300.
"10:1 geometric, than once the exhaust port closes the the compression ratio could not be much more than 5:1." Very good point and this needs it own video - matt Orbital Combustion Process - ATTL
Well...petrol engines have lower compression ratio than diesel engines and diesel engine works on direct fuel injection....so hows pressure there! Can you explain
It does! Bosch DI use a stratified injection which uses a rich mixture to start the burn then adds more fuel which ends up being a lean burn, in some cases 60:1 AFR
what about a direct injected 2 stroke diesel running on kerosene it would be capable of high rpms much like a traditional 2 stroke also the hobby market have been using these kind of diesels for a long time scale it up direct inject it and play with the efficiency a lil bit and it would get better economy and make more power because kerosene has a higher specific output than gas and it would but cleaner
"kerosene has a higher specific output than gas" - where did you get this from? Kerosene has a HHV of 46.2 MJ/kg and gasoline has a HHV of 46.7 MJ/kg. Kerosene also has a lower autoignition temp than gas at around 20-40degC lower. Specific output is displacement over HP/kW, and kerosene burns more like diesel than petrol, i.e its flame speed is slower. Kerosene has a stoichiometric (air fuel ratio) of 15, while gas is 14.7. There not much in it, but gas is still the winner.
The Workshop your right gasoline does have a higher energy density but it does burn cleaner and in a high compression direct injected 2 stroke diesel engine it should be more fuel efficient and still produce sufficient rpms. kerosene does not need to have oil added to it like gasoline because it has sufficient lubricity so it takes one complication out of the system
Very good point - kerosene is generally not used in cars/bike becasue its not as volatile as petrol, so you don't get great homogeneous mixing. Old tractors and such used to run on kerosene, but most of them used gasoline to start then engine, then when the engine was up to temperature you switched to kerosene.
You have to think of the duration of the injection phase vs the speed of the piston. @ 10,000 rpm the injector will have to compete with rising pressure so 5 bar wouldn't be enough no
For the past 15 years I've been wondering what the point of 2 strokes still is. I mean other than say a chainsaw where the engine may have to run on it's side or upside down and the fact that the oil is in the fuel becomes a technical benefit over having a 4 stroke engine that would need to run a pressurised oil system to deal with that kind of use. From my perspective, the EU could just blanket ban 2 strokes for just about any application, bar a few very specialist ones. Almost anything a 2 stroke could do can either be done by a 4 stroke or by an electric motor. Take a moped/scooter as an example. 2 stroke pre-mixed fuel is bordering on 3 euro per litre. Well over a euro more expensive than regular euro95. And even then, 2 strokes tend to be more thirsty. Like my friend who still rides a 2 stroke Kymco GD, that thing gets maybe 5l/100km, but generally closer to 6l/100km. Meanwhile my 4 stroke Kymco Agility sips fuel at a very reasonable 2l/100k, generally slightly less. And there's no blue smoke by default, it's more quiet, and it'll actually idle without bouncing up and down in revs. 2 stroke engines for mainstream use died over a decade ago. It's time the regulations finish the job and ban them entirely.
To me DFI 2 strokes are the holy grail of ICE engines. Why haven't we done it sooner? Besides like chainsaw or motorbike 2 stroke where simplicity is the goal. In those applications I think a rotary would be far better because it is better suited to the high rpm. But think of a 2 stroke v8. What if GM built a 2 stroke direct injected LS motor? Or buggati built the next W16 engine with two stroke direct injection? Where a little HP loss is tolerable. And a suitable pump can be built. There have been 2 stroke gasoline v8s built before, they were for outboard motors.
Peter Hubbard, a viewer on here has been talking to me about a V8 2T he has. Its a V8 Evinrude & Johnson outboard ( originally build by OMC) "What if GM built a 2 stroke direct injected LS motor? Or buggati built the next W16 engine with two stroke direct injection? Where a little HP loss is tolerable." - it not all about HP, its more about the torque. A W16 2T would melt, and the torque would be crap.
Now you talking, a 2 stroke ls1 motor would be awsome, you could loop charge it through both int/exh valves and a blower for scavenging. It would need a special cam that runs at 1:1 ration crank speed.
Toyota has built such an engine. However it is large and heavy but at is quite the torque monster! A better and lighter version which has been pursued by Chrysler would be a uniflow scavenging (roots blower) with an ordinary intake port at the bottom or a sleeve valve. And those have been built too. Two stroke 4 exhaust valve diesels were built in the millions for decades by general motors who formed that division into detroit diesel. The Uniflow intake port-sleeve valve exhaust direct injection engine was a massive v12 of 26 liters called the Crecy. It was built by rolls royce to replace the Merlin for super marine spitfires. But with the advent of the jet engine it was abandoned.
How the fuck does that guy elboy get an offer from a major tv Corp????? mate with your knowledg or base knowledge and say a team or one good producer behind your thoughts who could fucking animate these concepts to break it down for a lamen as myself it would be vastly superior to shit content out now,,, maybe even have shows where you have a sit down with an expert or have employed engineers on from various corps to back your claims or dismantle them but the proving right or wrong means shit it's the fucking chase for greater knowledge and placing facts that are solid out for blokes wanna know....fucking cheers mate for the time you invest into this shit....
"i dont think you understand just how much 200bar is. it's a lot. this system need 200-400 bar. that's a whole lot. how are you gonna generate the 2000 bar this system needs? it would be counter productive to generate the 6000 bar minimum that make this work. i don't think you realize, it ruins the point of a two stroke to have it running pumps that produce 12600 bar."
You are wrong, look for Athena DICC tha inject with 3 Bar and uses a simple EFI injector. When the exaust port closes the preassure is very low, you get 200 Bar only on maximum compression, the injector inject when the exaust port closes.
"You are wrong" - LOL its called TPI - transfer port injection - that's not Direct injection - no matter how much Athena want it to be. KTM have the same system.
"Transfer port injection" - LOL - LOL - LOL. How can it be a port injection if all ports are closed during the injection ? Even the exaust port is closed, then it's a direct injection, no doubt ! You are just a 2 stroke hater.
Like a 2 stroke hater is a thing - fucking dumbarse. Show me where the Athena or the TPI system spray fuel into the cylinder when the ports are closed. A real direct injection system is the one owned by BRP. Whilst you play fucking warcraft fantasy games leave the engineering to me.
There's no reason to inject with the exhaust port open, they are smart, different to you. You should study a little more before you talk about what you simply do not know. Is the tip. www.ralph-dte.net/images/automotive_alternativo/motori_due_tempi_iniezione/iniezione_dicc/schema_dicc.jpg www.ralph-dte.eu/tag/direct-injection-combustion-control/
reasons why it doesn't work: 1: no one is doing it 2: im not creative enough to determine why no one does it 3: im smug enough to say it's just a fact of life 4: since the manufacturers are smarter than me, and im smarter than you
To argue the other side......... 1 - Piaggio has done it, KTM and friends are doing it including Evinrude 2,3, and 4 - from these comments/points I'm guessing your american and love video games.
Where you gettin' "16KRPM" from? Don't most gasoline engines red-line at about 6K, +/-? And don't a lot of diesels red-line at about 4K (like mine, if I remember right)? Okay, so that's only for 4-stroke, I guess. So every time you talk about 16KRPM here, you're only talking about a small gasoline 2-stroker?
"save 2 strokes"????? - 2 strokes arent dying... Just because certain sports no longer allow them, IE Motocross Racing, Doesnt mean they are dying.... 2 strokes will never die.... I ride 2T mx bike... a Honda CR 125... I will never touch a 4 stroke... had one, and it was shit for starting when hot, let alone requiring a bank loan to rebuild...
they dont make em.. havent since 2008.... Why? Because emissions.. People always say its because of noise output.. But its not.. 4 strokes sound waves travel further than 2 stroke sound waves... But regardless of the fact that kawasaki and Honda no longer produce 2 strokes, doesnt mean they are dying.. There are thousands of people, Myself included, want to see honda produce a 2018 CR.... 2 strokes have their fans, especially in motocross....
The video skips over much of the difficulty, and details of meeting emissions regs. The exhaust system is a critical part of the equation. Its not difficult to meet regulations, when the engine is "up on the pipe" its at lower rpm/load situations where its most difficult to keep un-burned fuel from exiting the tailpipe. As far as oil, if it completely burns its not an issue (at least here in the states where particulates don't factor in) You need to look into the snowmobile market, or even marine outboards. The sled market is absolutely dominated by 2 strokes. Back in 2003 Yamaha vowed to go 100% fourstroke. Since then their market share has plumeted to the point, that they don't even build sleds. They pay arctic cat to put yamaha decals on cat sleds. Arctic Cat, and Ski doo sell a mixture of 2 stroke and 4 stroke sleds. Both have a vast majority of customers choose 2 stroke. Polaris doesn't even build a 4 stroke sled. Ski Doo uses E-Tec injection (true direct injection, with voice coil injectors firing into the combustion chamber) Arctic Cat uses a hybrid system, with a single injector firing through the cylinder wall, above the boost port. At low load, it fires into the combustion chamber only. At higher load, it fires into the chamber, and into the crank case through a slot in the piston. Polaris uses indirect injection, firing an injector into the boost port.
do you know that mexico is full of aging undocumented american illegals immigrants who are there for mexican benefits? It just doesn't make the news in the US.
I like the fact that you explain everything little thing because it gives a better understanding
love the videos, I'm learning a lot! keep up the good work!
Cheers dude - matt
how about the ski doo etec series? they are direct injected 2 strokes that are fairly mass produced
Good suggestion, added to the list - matt
Im happy to see that a lot of people know about BRP Rotax E-Tec engines!
Brilliantly done
Preheating to a certain degree helps atomization occur faster if you only use coolant or exhaust heat to preheat just to a certain temperature.
You could also use self-lubricated ceramic parts for the pumping aspects of the injection system, if you can make an affordable option.
Nice to see a fellow Abom79 / Fenner fan.
I like the description of this video :)
Brilliant video thank u 👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍
Take a look at the Evinrude/Rotax E-tec direct injection system. A quite simple system with a electric powered coil and a ram that both works as a pump and a injector. czcams.com/video/daN72ij2eTU/video.htmlm20s
E-TEC direct injection pressure = 34 bar (500 psi).
source:
articles.sae.org/8157/
Good video that hakan Bjorkman. Perfect example of development and why 2t are far from obsolete. (or shite).
Ja sam - are you trying to say 500psi is not enough? Even though it works and is in production right now?
On the contrary my dear Ian...
+Ja sam I guess you where pointing out the difference between the figures claimed necessary in the video and the real world figures then? Apologies, and I`m glad I`m not he only one that noticed..
I was going to comment that Evinride is already doing it. Glad someone else already did!!
Suzuki X7 with direct injection and a sidecar to house the pump! Seriously though often wondered why there hasn't been a revival of 2 stroke engines with DI.
thanks
Nice lecture.
Curious about the Bimota V-DUE 500... How did they work? I heard they had separate/sealed crankcases like a 4t??? and passed emissions in 98, I know they had some problems (although later fixed with kits) do to Bimota pushing them out the door too fast, killing the company and a possible 2t revolution with it. I just have no Idea how they worked.
6:40 a gasoline engine might have compression ratio around 10:1 (just a coefficient nubmer) BUT the pressure at TDC will be greater due to an air compression heating (dynamic compression ratio or something like this) and this could be around 13-15 atmospheres (pressure measurement).
I think looking to marine applications, provides some other examples were they are common place. The complicated/heavy/high pressures etcetera direct injection issues have been solved with lower revving 5-6K and bigger disc placements1.7L- 3.5L. I think a review of new Evinrude ETec/ G2 engines may contribute to your analysis. The high tech management systems seem to have played a significant part also. Efficiencies were solved and torque was supreme in this sector for the last 3-5 years. (Looking at the Evinrude 2 stroke vs the Yamaha 4 stroke in the 300hp range - 2 stroke shows a reduction in weight of about 10% and a 10% decrease in displacement, this was were fuel and exhaust was managed into Eco friendly shifts in thinking. I hope to see road bikes again return with 2 stroke power but the above parameters may be too large at present but we hold out for electronic fuel pumps and other such components to reduce in size to perhaps fix all of this.
"I think a review of new Evinrude ETec/ G2 engines may contribute to your analysis."
- video already in the making my friend.
Loved the EXP2's Activated Radical Combustion system. Honda claimed this system was very fuel efficient, was an improvement in driveability and clean.
A dirtbike and a scooter were introduced with this technology. Then Honda went 4 stroke minded or something, because after 2000 everything went 4 stroke (including motorsport).
I hope something will save the 2 stroke, injection systems are a good step in that direction.
it was their dogma from the start. remember that nutjob bike called RC46(124 4t 4cyl)?
I have the honda pantheon.this is a fine scooter.very clean running .for over 20 years and their is no ash in the exaust
TM is introducing direct injected 2 strokes for their 2018 dirt bike line up.
As you said in the camless engine video, technology and materiels need to get to a stage where it becomes practical/necessary and cost effective. Until regulation, there was no need to further refine 2t but now they have to become cleaner they will begin to make use of new ideas and the problems will be overcome, just like 4t had/has to.
"Until regulation, there was no need to further refine 2t" - really? So Kawasaki and Yamaha weren't in competition like the other big bike makes?
Competition in the same class where major design deviations are not allowed. Further more the bikes could already produce more power than could be safely restrained so developing and complicating it more was unnecessary, until regulation intervened of course.
Common rail systems started on 1350basr. My 1.9dci from 2003 pushes at 1600bar. New common rails(2017) does it at 3000bar.
Yeah, thats for diesels, which due to their higher compression ratios need even more pressure to over come the pressure in the cylinder. Not only that but because they are compression ignition the fuel starts to burn increasing the pressure before the injector has finished firing, hence even more pressure required. For GDI they don't need to go as high as the injector will close before the ignition fires - matt
Pumpe duse diesel injectors operates at ~2000 bar and don't need giant pump(only cam), maybe some adaptation of those could be used.
But again this adds complexity etc. Might as well have a 4 stroke, pass the emissions testing and have more lower end torque
and thats mechanical injection which is coming soon
Do a supercharged Direct Injection 2-stroke with oiling system! 👍🏻 I bet the power output and efficiency would be incredible. We need a vid on it and possibly with more than a single cylinder would really be a game changer. It might be the rebirth of 2-stroke
"I bet the power output and efficiency would be incredible."
- i bet it wouldn't
Sorry, I meant turbocharger.
Which part, the efficiency, or the power output, or both? I mean, you're not blowing the unburnt fuel out the muffler with direct injection. Plus, whatever turbo pressure makes it past compression will go back into spinning the turbo, at least somewhat. No exhausting stroke needed. I guess it could depend on just how fast your 2-stroker can rev up to as well without failure.
It would require a new type of fuel pump but that is totally possible, just has not been done yet. You can have an eccentric, camlike surface for a rotor over a stator who force output is very high during points of maximum mechanical advantage. As one example. Because you would most likely be talking about single-cylinder engines for bikes, generators, etc.. it could be cost-effective.
in the earley 2000's evenrude had made a new outboard direct injected 2 stroke that was supposed to be better with fuel economy than an equivelent 4 stroke
very true but the BRP engines are really complicated, expensive and quite large. Take the specs from a Evinrude 115 - 1.7 litre V4 and produced 115 HP?! and it weighed 166kgs!
An R6 is 190Kgs fully fuelled and ready to go, makes 122Hp and is only a 600cc. Are you gonna say that the Evinrude 115 has better fuel economy than the R6?
and X size pump can be used on how many cylinders? If its unlimited the more cylinders the more you counteract that weight. Right?
Simple answer to all this, Matt. Direct injection makes more sense on bigger engines. So ... 1000cc two stroke motorcycles are the best option. Make it so! :)
Gasoline direct injection is becoming the norm on new cars and even economy cars. The high pressure pumps are typically smaller than a fist and don't require special lubrication. They could easily be used on a motorcycle engine. Horsepower goes up and fuel consumption goes down which is why it's now in wide use despite slightly higher costs. On a direct injection 2 stroke, however, you would need to lubricate the crankcase.
There are different types of direct injection, not the one I talk about here.
Part 2 - czcams.com/video/snAGoUzI_Pw/video.html
How about a two stroke fuel injected motor that works with a supercharger like a diesel but uses a spark plug and gasoline? The crankcase wouldn't be part of the cycle...
This already exists. But it's mostly used in marine applications where emission regulations aren't as strict. They even burn crude oil.
Have you seen the Mahle jet ignition also could a pre chamber change injection timing and injection pressure?
Yes
Dry sump engines in airplanes can be operated up side-down. The crank case will need oil misting and a scavenge pump. It can be done
Certain snowmobiles, namely Polaris sleds, had both oil injection and fuel injection starting in the late 1980's and early 1990's. It is the Japanese manufacturers fault alone that they did not adopt this, despite the fact it's been around and in full use for near 30 years.
I know this is an old video but some of your facts are off a bit.
Yamaha was the first to offer oil injection as far back on production snowmobiles as 1969. Yamaha also offered fuel injection in 1977 or so on the race sleds.
Arctic cat was the first to offer fuel injection on production sleds and polaris was second though not by much. Polaris had to stop making fuel injected sleds ( short lived and only 2 models ) because they ripped off the original design from the automotive world so were sued.
At that time both Arctic and Polaris used Japanese engines ( arctic cat = Suzuki and polaris = Fuji heavy industries) so I dont think it was the Japanese who stopped 2 strokes from developing fuel injection.
the point of two stroke lubricating the entire engine with one source of lube. dfi has complicated it to much lublin the parts that with different systems to oil big end rod an crank bearings. they more work R&D to do.
what if you had longer than normal stroke and the the exhaust port was moved closer to BDC and combustion happened just as the exhaust port closed? Obviously this would decrease pressure... Right? If so how significant would the decrease be?
Great question, there's a video coming this weekend to answer this - matt
Cool, this is a very interesting topic. I'll definitely keep an eye out. Thanks.
can u do a reveiw of the ryger 2 stroke ? same for the 2-4 stroke engine? i want to know if they deliver what they claim
czcams.com/video/meY1QIU9xQ0/video.html
Rotax 800 E-TEC works at 7.900rpm (147hp from 800cc, 35.8kg), direct injection pressure is 34 bar (500 psi):
articles.sae.org/8157/
The latest one is the E-TEC 850 - czcams.com/video/jo-r7LwI70Q/video.html
Great engine, but my god it must cost alot. In the video the guy states that - "with a forged crankshaft and oil feed just like a 4 stroke, for reliability" - my point exactly lol
Maybe expensive, but no more than 4 stroke DI, and because no parasitic losses of cams, valves, etc. don't you think it's potentially more efficient?
I’m so fuckin drunk, I’ve given up thinking about this. All I know is I need to get my rs250 on the road. It’s taking a lot of effort
It kinda makes sense, but what about cylinder lubrication?
Pressurise your fuel reservoir. Required - Petrol tank, petrol, foot pump, pet elephant. ( I think an Elephant can exert a foot force of 2000 bar. If not train it to jump up and down) Easy.
Paul Dutton Elephants can't jump.
Yes simple answer, did my uni dissatation on it (92% i got on it :P). Was suprised how many uni profs wanted to read it. Lighter, more power to weight, list goes on . The only thing that let the concept down was the short circuiting of unburnt fuel and oil. Inject the fuel in when the ports are shut and add cleaner burning oils there you go. KTM are planning on releasing a new two stroke with this technology.
Would you send me your dissertation?
Yeah ofcourse, i will need to find were my electronic copy but think i know where that is :) I will drop you a message when i find it.
That would be very cool - matt
@Luca Mont Hi, i found the soft bound copy but soft copy i did not. However now you have reminded me again will have a look on my old laptop this weekend :)
Hello mate, this is Doru from Romania, I had an ideea and I thought I should take a second opinion, especially I've seen a lot of your videos from this 2 stroke DFI series and you're good, my question is why not to put a low pressure fuel injector exactly under the exhaust port, and time it to spray in the opposite direction of the intake port in the intake stroke ? I thought that because of the crossing of the atomized fuel and air the mixture will be more refined and the thermal efficiency will be better, and because of the pressure of the atomized fuel, the mixture will be thrown in the opposite corner of the cilinder, considering the exhaust port, and hopefully the engine speed will close the exhaust port before any of the mixture can escape the cilinder, hope to hear you're opinion, have a good one 🙂(PS :I'll work on a 3D model, if you're interested)
So you wanna stick an injector in the exhaust port? Or directly under it? Hope it can survive the temperatures.....
The Workshop under, at a certain angle, but my main concern was the temperature, you'll need a superinjector to handle such temps
What the fuck is a superinjector? LOL
Then you can't port it lol
does that not mean with dfi the port positions can drastically be changed to almost perpendicular positions? could the crank then be sealed to run in oil for lubrication, with a cylinder inlet port?, or would the crank still need to be used as a pump?.. suppose that is a 2-stroke diesel engine lol.
Great question, this video might help - czcams.com/video/snAGoUzI_Pw/video.html&lc=z122yz1oklqfyh5kg23qhluiiznsyx0an04
You are right on most of things, but your fuel pressure values are awfully wrong here. As piaggio (aprilia) in early 2000's made direct injected 2 50cc stroke scooter and it used air assisted direct injection after closing exhaust port with max air pressure of only 8bars. Called DiTech. Look it up. Ecu Rev limit was 10000rpm. Had one.
"but your fuel pressure values are awfully wrong here"
Come on dude, if you're going to call someone out get it right. The DiTech (morini system) and/or the Purejet (piaggio system) is in theory a direct injection system but in the same way the TPI system is on the KTM. The injector spray fuel into the cylinder just as the exhaust port closes not like the Etec system or at TDC like diesel systems.
They were soooo good that they're no longer used.
@@dirtygarageguy Your responses do not need to be rude in order for you to reply.
To quote you in this video: "As soon as you close your exhaust port you can spray fuel. The problem is that then piston is very close to TDC and that the pressure is quite high ~ 8-12 bar."
Which is incorrect. And you're trying to avoid the fact by trash talking about the system itself.
Direct injection is every injection that has injector located in cylinder head and sprays directly into combustion chamber, no matter the timing of injection itself. I didnt say that DiTech was perfect in any way, as it was a first attempt at that technology. But it did what it was advertised for.
"The problem is that then piston is very close to TDC and that the pressure is quite high ~ 8-12 bar.""
- yeah, very close to TDC the pressure is between 8 to 12 bar. Have you ever done a compression test?
"Which is incorrect."
- do a compression test and get back to me.
"Direct injection is every injection that has injector located in cylinder head and sprays directly into combustion chamber, no matter the timing of injection itself."
- Very true - not arguing that, however when an injector fires is very important when concerned with fuel pressure.
"But it did what it was advertised for."
- What did it advertise?
Oh and to add - this is a video that is generalised.
@@dirtygarageguy Read what you said again, its "then", not "when". Changes the meaning of sentence.
It makes sense to inject as soon as exhaust port closes as it gets the unwanted 2 stroke wasted fuel flaw sorted out. Only thing why would you inject at TDC is stratospheric lean burn, which you don't need to use. Its not a diesel that you need to inject at tdc in order to get the mixture ignited, you have a sparkplug there to do the job.
P.S. all the injection problems that you describe here have actually been sorted out, but not for two strokes but your beloved 4 strokes (Audi/VAG TFSI) and they work very well so no point in discussing that problem as the solution is already there.
DiTech was advertised as "new" technology, better power/torque than same 2stroke carbed models (and 4stroke) and better emissions and fuel economy than both conventional 2 or 4 stroke engine.
Never advertised as reliable. (damn Italians)
FYI. Ktm has now released the EFI 2t motors.
Don't worry, I gonna tear into KTM soon
Matt, do you think someone will succeed in doing Direct High Pressure Fi on 2 strokes in a few years ?
Or will they abandon the IC engine all together and go electric dildo on wheels route ?
That's what I would like to know to. And maybe there could be a way to reduce the emissions from the oil scraped off at the exhaust port. I really hope 2 strokes don't die.
@@EbonyPope They are already dead as far as I am concerned. But I love them and ride one! Plus people want to ban Diesels which are cleaner than even the cleanest 2 strokes :/
Why does my 300cc 2 stroke only have a compression of 6.9:1? Can you explain why they chose to go so low and what benefits and why/how increasing the compression (and to how high) would have? :D thanks great videos!
Thanks for the comment dude - can I ask what engine it is from?
some manufactures calculate compression ratio from the point the piston closes the exhaust port, some from BDC
Look at Evinrude E-tech outboards. Very successful 2 stroke efi engines.
Already have - and I have an etc injector
Mark Turney I am sad this covid crap killed them off
can you make a video about types of sportbikes engines layouts?
In what way? like V4 vs straight 4?
v4 vs straight 4 vs 2L from ducati please
take your time whenever you're free :)
No worries mate, that's already going to be covered in the Cylinder Configuration videos, but I can do a direct comparison
ok that would be great thanks for being responsive mate
The biggest problem with 2 stroke is the ethanol in gasoline. When ethanol sits for even a week it absorbs air moisture and washes out the oil; overheats the piston and case. I just bought 1 gallon of Stihl motomix for my chainsaw and it was $34.99 US.
"When ethanol/gas sits for even a week it absorbs air moisture and washes out the oil its mixed with;"
- LOL you do realise that petrol/gasoline is a solvnet for oil, not water. Water and oil don't mix LOL - and i've done a video about how much ethanol absorbs water, and after 3 months its not that much at all.
One other problem with what you just said. Gasoline is what cools engines and your piston, not the oil. Oil is there to reduce friction.
Ethanol is hygroscopic meaning it absorbs water and does so 50 times it’s mass. Google “ethanol absorbs water”
The Workshop- on a side note, I have a 1981 ATC 250R with a steel sleeve. I had it bored 2mm over. With a larger carburetor will it make more power? Do I need to change the mix? It’s 20:1 now stock
"Ethanol is hygroscopic meaning it absorbs water and does so 50 times it’s mass."
BRAHAHAHAH! Are you fucking insane, just think about what you have written for 1 second. That means that if you has 1 litre of ethanol it absorbs 50 litres. How the fuck and where the fuck does all that water come from? LOL You do realise that water weighs 1 kg per litre.
Ethanol is hygroscopic, and over 3 months tested samples of E10 absorbed 3% water of the ethanols mass - which was 50g of ethanol. 3 MONTHS! Do you understand how dry air is?
"The Workshop- on a side note, I have a 1981 ATC 250R with a steel sleeve. I had it bored 2mm over. With a larger carburetor will it make more power? Do I need to change the mix? It’s 20:1 now stock"
- 2mm increases your dispalcement from 246cc to 261cc - that's a 6% increase, so no, you'll be fine. And no, the premix is based on fuel volume - you draw in 6% more fuel then 1/20th of that will be oil
I didn't realize this was an option or ongoing project for the two stroke world... I started riding 4strokes about ten years ago and haven't seen a need for anything else since. although I do sometimes rebuild two strokes for friends that still prefer whining over the power of modern technology.
how would the crank and main bearings be lubricated?
Good question, that will be in part 2 - matt
One distinct advantage of 2-strokes that ensures they aren't going away any time soon is no crankcase oil. why? It can run upside-down. this is one advantage I haven't heard you say yet. the only real replacement is the electric chainsaw.
I do here - czcams.com/video/lUrDgY_pj08/video.html
when the exhaust port closes what is the cylinder pressure? I doubt it could be much more than 2 bar. If the compression ratio of a two stroke is 10:1 geometric, than once the exhaust port closes the the compression ratio could not be much more than 5:1.
I noticed no discussion of the orbital air assisted fuel injection. I am sure you must be aware of them. Have you looked at the retrofitting by Envirofit of 2 strokes in the Philippines? 1 cylinder 100 cc taxi motors were retrofitted with an Orbital based air assist for less than $300.
"10:1 geometric, than once the exhaust port closes the the compression ratio could not be much more than 5:1."
Very good point and this needs it own video - matt
Orbital Combustion Process - ATTL
My sled is a DI two stroke and its a fuckin animal.
So how would it be possible to fuel inject something like a Vespa engine, if it is possible???
Are you asking me how can YOU? or are you asking how can they do it on a vepsa engine?
death to all scooters!. get a motorbike!
i know Evinrudes had this for a while now.
Well...petrol engines have lower compression ratio than diesel engines and diesel engine works on direct fuel injection....so hows pressure there! Can you explain
Do you mean how comw diesels have higher pressure?
It’s often solved with high pressure around ~2000bar or higher. For example Volvo has common rail pressure of 2500 bar.
couldn`t you theoretically put it in the exhaust port. i know it sounds weird but it sound like a potential.
Put what in the exhaust port? An injector?
Why doesn't DFI mimic a lean run situation?
It does! Bosch DI use a stratified injection which uses a rich mixture to start the burn then adds more fuel which ends up being a lean burn, in some cases 60:1 AFR
Why does the fuel have to go through the crank case?
pumping, otherwise how would you you get it in?
what about a direct injected 2 stroke diesel running on kerosene it would be capable of high rpms much like a traditional 2 stroke also the hobby market have been using these kind of diesels for a long time scale it up direct inject it and play with the efficiency a lil bit and it would get better economy and make more power because kerosene has a higher specific output than gas and it would but cleaner
"kerosene has a higher specific output than gas"
- where did you get this from? Kerosene has a HHV of 46.2 MJ/kg and gasoline has a HHV of 46.7 MJ/kg. Kerosene also has a lower autoignition temp than gas at around 20-40degC lower.
Specific output is displacement over HP/kW, and kerosene burns more like diesel than petrol, i.e its flame speed is slower. Kerosene has a stoichiometric (air fuel ratio) of 15, while gas is 14.7. There not much in it, but gas is still the winner.
The Workshop your right gasoline does have a higher energy density but it does burn cleaner and in a high compression direct injected 2 stroke diesel engine it should be more fuel efficient and still produce sufficient rpms. kerosene does not need to have oil added to it like gasoline because it has sufficient lubricity so it takes one complication out of the system
Very good point - kerosene is generally not used in cars/bike becasue its not as volatile as petrol, so you don't get great homogeneous mixing. Old tractors and such used to run on kerosene, but most of them used gasoline to start then engine, then when the engine was up to temperature you switched to kerosene.
The Workshop that is why you need a high compression engine as well as having a high pressure injection system to properly atomize the kerosene
Isn't pressure ~1 bar in the moment of closing the exhaust port?
In the cylinder before combustion? Yeah pretty much
So a low pressure direct injection (4-5 bar?) would be enough in that moment?
You have to think of the duration of the injection phase vs the speed of the piston. @ 10,000 rpm the injector will have to compete with rising pressure so 5 bar wouldn't be enough no
I agree, do you have any data on piston speed at max rpm and direct injection speed/duration so I don't have to search/calculate?
For which engine?
For the past 15 years I've been wondering what the point of 2 strokes still is. I mean other than say a chainsaw where the engine may have to run on it's side or upside down and the fact that the oil is in the fuel becomes a technical benefit over having a 4 stroke engine that would need to run a pressurised oil system to deal with that kind of use.
From my perspective, the EU could just blanket ban 2 strokes for just about any application, bar a few very specialist ones. Almost anything a 2 stroke could do can either be done by a 4 stroke or by an electric motor.
Take a moped/scooter as an example. 2 stroke pre-mixed fuel is bordering on 3 euro per litre. Well over a euro more expensive than regular euro95. And even then, 2 strokes tend to be more thirsty. Like my friend who still rides a 2 stroke Kymco GD, that thing gets maybe 5l/100km, but generally closer to 6l/100km. Meanwhile my 4 stroke Kymco Agility sips fuel at a very reasonable 2l/100k, generally slightly less.
And there's no blue smoke by default, it's more quiet, and it'll actually idle without bouncing up and down in revs.
2 stroke engines for mainstream use died over a decade ago. It's time the regulations finish the job and ban them entirely.
To me DFI 2 strokes are the holy grail of ICE engines. Why haven't we done it sooner? Besides like chainsaw or motorbike 2 stroke where simplicity is the goal. In those applications I think a rotary would be far better because it is better suited to the high rpm.
But think of a 2 stroke v8. What if GM built a 2 stroke direct injected LS motor?
Or buggati built the next W16 engine with two stroke direct injection? Where a little HP loss is tolerable. And a suitable pump can be built.
There have been 2 stroke gasoline v8s built before, they were for outboard motors.
Peter Hubbard, a viewer on here has been talking to me about a V8 2T he has. Its a V8 Evinrude & Johnson outboard ( originally build by OMC)
"What if GM built a 2 stroke direct injected LS motor? Or buggati built the next W16 engine with two stroke direct injection? Where a little HP loss is tolerable."
- it not all about HP, its more about the torque. A W16 2T would melt, and the torque would be crap.
Oh wait I forgot the W16 get insaly hot sorry!
Also here's how to solve high injection pressure problem: Air blast injection.
Now you talking, a 2 stroke ls1 motor would be awsome, you could loop charge it through both int/exh valves and a blower for scavenging. It would need a special cam that runs at 1:1 ration crank speed.
Toyota has built such an engine. However it is large and heavy but at is quite the torque monster! A better and lighter version which has been pursued by Chrysler would be a uniflow scavenging (roots blower) with an ordinary intake port at the bottom or a sleeve valve.
And those have been built too. Two stroke 4 exhaust valve diesels were built in the millions for decades by general motors who formed that division into detroit diesel.
The Uniflow intake port-sleeve valve exhaust direct injection engine was a massive v12 of 26 liters called the Crecy. It was built by rolls royce to replace the Merlin for super marine spitfires. But with the advent of the jet engine it was abandoned.
It was the toyota s-2
How the fuck does that guy elboy get an offer from a major tv Corp????? mate with your knowledg or base knowledge and say a team or one good producer behind your thoughts who could fucking animate these concepts to break it down for a lamen as myself it would be vastly superior to shit content out now,,, maybe even have shows where you have a sit down with an expert or have employed engineers on from various corps to back your claims or dismantle them but the proving right or wrong means shit it's the fucking chase for greater knowledge and placing facts that are solid out for blokes wanna know....fucking cheers mate for the time you invest into this shit....
Other Problem: with direct Injection Young Need a seperate oil System because fuel wont Hit The Most Parts of the cylinder
What's with the weird CapITal leTterS EverYWHerE?
Im sorry im using a german Keyboard the Capital letters get replaced automaticly
the catalytic converter will save the 2 strokes , lmao
probably not for long, most of us know a two strokes fires twice the amount of a 4 stroke so theres twice the emmisions to deal with
Very true, and this is why I said that they might just meet the emissions standards but not for long.
That makes no sense.
It fires twice as often so it will have twice the work output.
Emissions per power stroke are what matter.
Evinrude walked os these guys can run. Too bad nobody bought ETecs
I HOPE THE FUCK SO
Enviroude do that with big engines and closed
DFI has been saving 2 strokes since diesel 2 strokes have been made
lol All diesels have direct injection. Always have been. The video is about bike engines.
"i dont think you understand just how much 200bar is. it's a lot. this system need 200-400 bar. that's a whole lot. how are you gonna generate the 2000 bar this system needs? it would be counter productive to generate the 6000 bar minimum that make this work. i don't think you realize, it ruins the point of a two stroke to have it running pumps that produce 12600 bar."
Is this a question directed at me?
You are wrong, look for Athena DICC tha inject with 3 Bar and uses a simple EFI injector. When the exaust port closes the preassure is very low, you get 200 Bar only on maximum compression, the injector inject when the exaust port closes.
"You are wrong" - LOL its called TPI - transfer port injection - that's not Direct injection - no matter how much Athena want it to be. KTM have the same system.
"Transfer port injection" - LOL - LOL - LOL. How can it be a port injection if all ports are closed during the injection ? Even the exaust port is closed, then it's a direct injection, no doubt ! You are just a 2 stroke hater.
Like a 2 stroke hater is a thing - fucking dumbarse. Show me where the Athena or the TPI system spray fuel into the cylinder when the ports are closed.
A real direct injection system is the one owned by BRP. Whilst you play fucking warcraft fantasy games leave the engineering to me.
There's no reason to inject with the exhaust port open, they are smart, different to you.
You should study a little more before you talk about what you simply do not know.
Is the tip.
www.ralph-dte.net/images/automotive_alternativo/motori_due_tempi_iniezione/iniezione_dicc/schema_dicc.jpg
www.ralph-dte.eu/tag/direct-injection-combustion-control/
Hi folks , 2Ts moto x are still been made , Suzie RM , KTM have new bikes , the Suzie haz their old motor still , yep , 2T r us
2 strokes are what they are. I don’t think for motorcycles it can be bettered
direct injected 2 strokes have been around for decades
Diesel don't you mean, and pretty much 100 years
Electric is the way to go.Superconductivity with high technological graphene battery systems.Maximum torque from zero revs with 1000 mile range.
yeah good luck with that.
reasons why it doesn't work:
1: no one is doing it
2: im not creative enough to determine why no one does it
3: im smug enough to say it's just a fact of life
4: since the manufacturers are smarter than me, and im smarter than you
To argue the other side.........
1 - Piaggio has done it, KTM and friends are doing it including Evinrude
2,3, and 4 - from these comments/points I'm guessing your american and love video games.
Holy crap, trolling gets me more channel views than spamming.
Where you gettin' "16KRPM" from? Don't most gasoline engines red-line at about 6K, +/-? And don't a lot of diesels red-line at about 4K (like mine, if I remember right)? Okay, so that's only for 4-stroke, I guess. So every time you talk about 16KRPM here, you're only talking about a small gasoline 2-stroker?
no, I'm not talking about car engines.
So then weed-trimmer engines go 16K at top speed? Lawnmower engines tend to? Or only 2-stroke ones?
"save 2 strokes"????? - 2 strokes arent dying... Just because certain sports no longer allow them, IE Motocross Racing, Doesnt mean they are dying....
2 strokes will never die....
I ride 2T mx bike... a Honda CR 125... I will never touch a 4 stroke...
had one, and it was shit for starting when hot, let alone requiring a bank loan to rebuild...
and this shows what little you know. Ever tried to buy a 2 stroke from kawasaki theres days?
they dont make em.. havent since 2008....
Why? Because emissions..
People always say its because of noise output.. But its not.. 4 strokes sound waves travel further than 2 stroke sound waves...
But regardless of the fact that kawasaki and Honda no longer produce 2 strokes, doesnt mean they are dying..
There are thousands of people, Myself included, want to see honda produce a 2018 CR....
2 strokes have their fans, especially in motocross....
no thanks.. had a CRF 450, and that was an asshole to start when hot.. Even after valve shimmed correctly.
Soon got shot of that..
Snitchy1989 question, was it carburetor or fuel injected?
hater reasons
No I ain't
The video skips over much of the difficulty, and details of meeting emissions regs. The exhaust system is a critical part of the equation. Its not difficult to meet regulations, when the engine is "up on the pipe" its at lower rpm/load situations where its most difficult to keep un-burned fuel from exiting the tailpipe.
As far as oil, if it completely burns its not an issue (at least here in the states where particulates don't factor in)
You need to look into the snowmobile market, or even marine outboards. The sled market is absolutely dominated by 2 strokes. Back in 2003 Yamaha vowed to go 100% fourstroke. Since then their market share has plumeted to the point, that they don't even build sleds. They pay arctic cat to put yamaha decals on cat sleds.
Arctic Cat, and Ski doo sell a mixture of 2 stroke and 4 stroke sleds. Both have a vast majority of customers choose 2 stroke. Polaris doesn't even build a 4 stroke sled.
Ski Doo uses E-Tec injection (true direct injection, with voice coil injectors firing into the combustion chamber)
Arctic Cat uses a hybrid system, with a single injector firing through the cylinder wall, above the boost port. At low load, it fires into the combustion chamber only. At higher load, it fires into the chamber, and into the crank case through a slot in the piston.
Polaris uses indirect injection, firing an injector into the boost port.
2 strokes dont need to be saved
lol I think the 2 stroke department at kawasaki would disagree
Maybe that’s why Kawasaki have had their day probably the most undesired dirt bike currently
2020 and the 2 stroke is still going strong just ask the Yamaha department if u don’t believe 🤣
correction, trump will save the 2 strokes
And the mexicans!
Your right, he will save the legal Mexicans from those horrible illegal immigrantsgo trump
do you know that mexico is full of aging undocumented american illegals immigrants who are there for mexican benefits? It just doesn't make the news in the US.
littlegoobie you need to lay off the dope. There are no benefits to being an elderly illegal immigrant in Mexico