It's probably been brought up before, but one could design a wet sump 2 stroke with a blower pushing in the air instead of the downward pressure from the piston, that would elimate the need for the fuel mix as the Detroit 2 stroke diesels did. The injector could be fired right as the piston covers the exhaust port preventing blow through of the fuel.
The E-TEC is somewhat close, but still injects oil instead of using a wet sump. Instead as you say, mount a turbo wheel compressor to the crank to charge the air instead of messing with oil injection. I do like the variable size E-TEC exhaust however, that is slick.
I've seen this back in the 80's and told the engine was "killed" Using an air pump (turbo). The intake pressure pushes out the exhaust. Cycle timing is. 0deg TDC is detonation 90deg exhaust opens and relieves pressure. 110deg intake opens and the pressure removes the rest of the exhaust until 180deg. from 180deg to 360 is compression stroke. The injector can almost remain open with multiple cylinders using a throttle body method. 1 single injector vaporizing and mixing. Please try it out.
They have been doing it on boats since the 60's two cables connected to the throttle linkage and sliding expansion pipes usually found on hydro hulled boats. They slide around 4 inches and most are not sealed. Honda Racing Corporation had a system on some NSR500 racers, by adding a water tank to the bike, with a 3/4ths gallon volume, and a computer driven pump, to inject water vapor into the primary pipe. The steam created an offset of volume in the head pipe, changing its flow rate, making the engine think the exhaust system was of smaller dimension at lower rpms, for more low speed torque production, then their is the powervalve Yamaha developed which varies the exhaust port height. They are all proven tech and can last many many many miles.
I like these videos , you make it feel natural for us to watch you by swearing drawing an not staring at us constantly very good way to film vids , and easy to understand what your going on about
For the love of twostrokes, I really hope that you one day will have the fortune to drive a Yamaha SRX700 snowmobile. An inline 3 cyl twostroke. I bet you will have a hard on.
4t snowmobiles are heavy. The 3 cylinder twostroke engines were awesome, great torque etc. But also heavy and wont fit in the cassis. That's why all the snowmobile mfgs use 2 cylinder engines now, be it 2 stroke or 4. You can't even compare a 15 year old sled with a new one. The difference in rideability is ridiculously large!
@@theq4602 to be fair there are some.pretty nice diesel bikes built for off road stuff. The US military bikes based off the KLR650 is amazingly nice to ride. Like REALLY nice to ride.
The Fitch injectors used on kawasaki jetski are electric operated, there is nothing unsafe about them, only high pressure is going into the cylinder. It does need a 40psi input, which isn't totally safe vs a 4psi carb. I believe the direct injected two stroke is the best engine ever, and totally surprised it hasn't taken over by now.
way back in 1980 we had a Honda XL 185 four stroke and a Yamaha DT 175 which were about equal in performance and fuel economy. most 2 strokes in aircraft engines are half the CC of the four strokes. would the economy improve if they were same size but detuned with lower exhaust port roofs?
@Tobias Cat as far as i know the Etec system is s direct injection which injects fuel closer to TDC after all ports are closed. They use an oil pump to deliver oil to internals. I'm not sure why they didn't render 4 strokes irrelevant. Could be lack of public awareness to overcome the negative sentiment towards 2 strokes.
@@dirtygarageguy thanks. wouldn't the power to weight ratio make up for these efficiencies? any new videos coming on your new engine design, think it was a hossak?
Air blast injection? Also what about those old IDI diesels with the antechambers on them. From 1988-1994.5 ford bought big 7.3 liter V8 engines for their pickup trucks. (previous 4 years were 6.9 liters) These engines were the antechamber type, with a single injector pump the size of your fist back in those days making ~190HP and ~360 ft-lbs of torque. They had a few high pressure fuel lines running to pop off valve type injectors with springs in them that popped at about 1900 psi and these injectors are smaller than modern 4 stroke EFI injectors. A set of remanned ones can be bought for around 200.00/160 pounds. Why not use a simple old mechanical pump like those? The pump could be TINY on a 1/2 liter two stroke. Probably finger sized (a large guys finger) if its a plunger type. Not really much more complexity.
That injection system relies on the lubricity of diesel fuel and would fail rapidly if used for injecting gasoline. It also relies on the higher viscosity of diesel fuel to 'fill' the clearances between parts creating the high pressure seal without allowing metal to metal contact.
Dumb question but why not have an oil injection system fed to an internally hollow crankshaft where its orifices feed the only spots needed for lubrication, squirters for the underside of the piston if need be? It resolves the need for a crankcase reservoir, retains the basic parts of a 2T engine and still can utilize direct injection.
@@dirtygarageguy ultimately yes, oil will almost always become a byproduct at that point, however less could be used since it would be pressured and oil fed to only the most important locations
Less is still too much. Think of it this way, 4 stroke engines like the hayabusa are failing euro 5 emissions... 2 stroke burning any oil have no chance.
@@dirtygarageguy for today's emissions mandates and regulations, sadly the 2 stroke has a short life ahead of it. It did make a comeback at one point from carb to TPI, the improvements made were substantial. What's to stop another person to redesign it to work within today's stringent requirements?
infact there is a bloke who put a 2 stroke triple snowmobile engine in a bike. trouble is he only seemed to have one gear like a scooter. it was cool though and sounded wicked
I drive a direct injected 2T moped and I can say that it is fucking great! It goes much faster than most other original mopeds! It is a Aprilia SR50 DiTech with the Aprilia engine. It makes 5hp with all the restrictions on it and everything! Unrestricted they say that it will do 70mph isch. But i can tell you that the complexity of that motor is very basic! I am only 16 and I've restored the whole thing on my own. It is much simpler than a engine with a built in gearbox. Look in to it and see for yourself ;)
Worked on high pressure hydraulic systems building and testing valves ,i have seen 9000 psi just before it went bang big time really lucky not to get hurt ,but it did rain oil for a bit ,ive heard of someone looking for a oil leak on concord it used such high pressure lines that it cut his fingers off even a small pinprick could lead to amputation the only way to release oil in your flesh is by cutting around like a peeled orange.So think before you touch around fuel lines and injectors I think your show is great specially the rants
I shit you not, we might have an identity of who it is. The misses great uncle flys around these parts on the weekend. I need to get the serial number off the side and ask him what plane he has. I know its a Cessna 152 but haven't read the registration. More to follow if I can get photos etc......
Snowmobile engines are quite awesome. They are shrouded because of the ambient they must perform in and running them above zero is detrimental. It can be done but, serious thought on cooling is required.
Yes but, both those other examples are water cooled. Had a go-kart that was powered by a snowmobile engine and had to create ducts to channel more air to the engine because of the way it was constructed. I enjoy your commentary quite a lot because you're a man's man, no b@llshit here. It's late for you there. We're 4 hours behind you.
I have never seen a Direct Injected 2-Stroke Sled (Doo E-tec, Polaris CFI, Cat C-tech) that was air cooled... Most High Power Snowmobile engines are Liquid Cooled. Air Cooled 2 stroke snowmobile engines can be used in the summer, but jetting and cooling must be planned correctly.
Matt, this chanel is bloody brilliant. Keep the videos coming. This might sound daft But do you think there could ever be a form of dry lubrication. Eg Graphite or some kind of ultra low friction coating in The future?
Also a problem with two stroke injection is pluse rate. I run a drag sled that revs to 13,500. I tried to get it on efi but the injectors wouldnt stay open after 9500rpm. You bring up formula one and they rev to 20k but the injector is only opening 10k a minute. There hasnt been much technology to make injectors work past that as 99% of engines dont need to have injectors to pluse at 200 times a second.
The trick is to not use the crankcase as the compressor: use a separate supercharger or turbocharger. That way the lubrication stuff is kept away from the combustion stuff. Then make the intake at the ports at the bottom, and the exhaust as four valves at the top. This also keeps a steady temeprature gradient along the cylinder.
you could do it the way a 2 stroke diesel does it with an exhaust valve but just add a spark plug alongside the injector. you would obviously have to change some things like the compression could be lower. and 2 stroke diesel can be supercharger and turbocharged. you'd have to add an oil pan and sump tho cause 2 stroke diesels use a oil sump and a pressurized lubrication system instead of relying on oil in the fuel but diesel is also somewhat of a lubricant so that helps it.
stupid question, but what if you just put oil in the crank case, plug the transfer port on the crank case side and supercharge air into the cylinder through the transfer port? that means no oily air, no oil in the exhaust, etc. fresh air pushes out smoke, exhaust port closes, injector fires, spark, boom. sure this won't solve the problem of dispersing the gas quickly enough, but this could work for lower rpm clean burning 2 stroke. sure, now we need a supercharger but I said in the beginning it's a stupid question lol
In my experience, the FICHT Direct Injection Polaris Watercraft and Johnson/Evinrude two stroke engines run amazing. So it's been done and perfected already?
The diesel has big displacement and high compression ratio, fuel pump shouldnt be a problem on 2 stroke direct injection. Not to mention that diesel also injects in TDC.
Bro if 2 stroke with direct injection does that mean i don't need to use 2T oil in the combustion chamber but the 2T oil will work as a lubricant oil with also the engine oil? or mix petrol and 2T oil in the injector injector?
They should help emissions by porting the exhaust. The port should close when all the burnt gas is out and opens to let it out. It should help with the build up of oil and gas in the exhaust pipe
One could solve the problem of drawing power from the engine by using a battery to power the injector. It would not be ideal for everyday use, of course, but for someone who has a ktm 200 exc or something similar to use on the weekend, a battery would probably do the job. The problem then would be the weight of the battery (but it could be used to optimize the CoG) and the battery life. If the battery could last 90 minutes of recreational use, it would be more than enough. If not, a small percentage of the engine's power could be used to extend the battery's life.
You barely touched one the one undeniable advantage of 2- strokes but you did touch on it. Most backpack blowers are 2T (2- stroke) blowers and work great. A company (i think Makita) came out with a 4T (4- stroke) blower. It is actually pretty impressive. Noticeably heavier but not uncomfortably, CONSIDERABLY better fuel economy, and no more having to have 2T fuel on the jobsite. BUT, they can't run upside-down. A blower can stay upright. A chainsaw absolutely cannot. In just about any application that oil pick up isn't an issue, a 4T motor CAN produce more power more efficiently. How? A turbo. You can take a 125cc bike, increase to 183cc, turbo, and be at 40hp. You cannot get that out of a similar sized 2T. And as close to that as you can get with a 2T, let's say race built 200cc, it'll burn considerably more fuel. For comparison. We have a Husqvarna 3120XP (120cc) chainsaw. That thing burns about 2-3gal/hr at wide open throttle. My MSX125(125cc) has slightly less power (which a cam and tune would easily fix) but averages 75mpg when i ride wide open and 115mpg IF i ride normal. If i had to guess, it would be about 1-1.2gal/hr wide open throttle. BUT, the 125cc CANNOT run upside- down. Hell, it can't even wheelie because the oil pump is the oil pick up and is in the front of the motor. So, pound for pound, with a turbo, 4T is more powerful. But, 2T cannot be replaced for chainsaws and other 2T equipment that has to run in any orientation.
The Workshop to touch on motorbikes, no reason for 2T anymore except nostalgia. 4T turbo would kill them. Though they have the advantage in price, the maintenance and fuel efficiency makes a turbo 4T a more desirable choice. With the exception of nostalgia of course.
Russ Jamison and you can make a race built 4T turbo that'll be faster (less HP but tons more torque). Anything is possible. But the 3120XP(120cc) is designed to run... 1000hrs without fail? Putting out 12hp. And the 3120XP has another trick: no reed valve. Stupid simple. The MSX125(125cc) is 8hp in a stock anemic tune with 14:1 air/fuel and 9.6:1 compression. But, the MSX125 cannot run much beyond 45 degrees lean angle of the motor. The 3120XP can run in any orientation.
My 2 stroke grass strimmer will only start if I remove the spark plug and inject fuel onto the piston Replace and it starts first time and continues to do the jib. Is it the carb fuel bulb is sucking up from the fuel tank ok. any ideas
Couldn’t you have a rotary valve like ski doo had in the 90s, and have the exhaust closed until atdc then when below the exhaust the disc closes exhaust, and inject the fuel mixture when the piston is on the bottom part of its stroke?
outboards got fuel injection in the 90´s. there are many di two stroke engines. tohatsu tldi, yamaha hpdi, evinrude e tec just to name few. also snowmobiles got similar engines
What i never understand is that 1 person riding a 2T bike surely would be doing less damage to the environment in comparison to 1 person driving a 2L+ diesel or petrol 4x4 which you see daily?
Let's have a scenario here. We stop using the crankcase pump air into the cylinder and instead use some form of forced induction. This would mostly fix the oil issue from what I understand. Then, we use a valve on the exhaust port to stop the fuel-air mix from escaping with the exhaust. Or, we find some unobtanium-based way to fix the problems of the two stroke engine. My question is, is there a benefit over four stroke engines created by having twice the number of power strokes in the same number of reciprocating movements of the piston?
To those who might think Matt might be over exaggerating with the dangers of high pressure injectors... Try look up Hydraulic Injection Injury... Not for the faint of heart mind you. It is a real danger and if you EVER get a "stingy" shot GO TO THE ER ! You might not be able to see it, but that does not mean you have not been hurt. BTW great channel Matt ;-) Meet you here about a week or two ago and i am freaking hooked :-P
But the system is only under pressure when the engine is running. The moment it's stopped that high pressure is gone so the danger to a person servicing it is 0....unless he's trying to take apart a running engine in which case he has many other hazards to consider.
@dirtygarage guy. How about doing a video on Strato charged two stroke technology as patented by Komatsu and as used on most 2 stroke outdoor power equipment today?
whats about a combination of a carburettor and injection. the carb would give a very lean gasolin oil mixture... and the main gasolin regulation takes place with an injector... some thoughts: the carb needs to handle a seperate oil regulation to give more oil on high rpms, why dont we put an injector in the transfer port? , i think powerloss on an all mechanical fuel pump with fuel regulators wouldnt be such a big impact.
I wish manufacturers would embrace "responsible modification" or something and tell people how to do it safely and without fucking up the engine. Im into snowmobiles personally, but I think you guys in the motorbike world have the same issue as us where the companies only want to cover their ass from liability
What about a wet sump just like in four strokes. I know the problem with how are you gonna get air into the cylinder but ive been thinking about turbos. Since the injection is after every port is closed you wouldn't need expantion chambers and backflow and all that stuff so a turbo wont fuck it up like it would with a carbourated engine. And if the turbo would steal too much power an electric one wouldn't need much power since it only has to make like one bar. Im not thinking of forced induction but while the piston closes the inlet port it builds up pressure and as soon as it opens it would flush out the exhaust and replace it. The upper part of the cylinder might be hard to flush but then again it is as you said with port geometry
Jetski engine in a bike would be fun but you'll have trouble cooling it because they run cold water, total loss cooling systems. Snowmobile engine would be the way to go.
poor thumbelina and her mates 😢. I agree with yourself that it's just not worth the hassle of all the research and development when 4 strokes have moved the game on so far. I rode behind my dad's 2 stroke for half an hour and I had a headache and felt like something was stuck in my throat. But still have massive respect for them. Just don't want them to make a comeback cos it won't be like it used to be.
Great show, enjoy your style, Keen to hear what you think of the Tohatsu low pressure fuel injection two stroke outboard ~40 hp and larger. I do like the smell of tts Kind regards Donald New Zealand
Gas is a lot less dense that liquids. So you have to pump a lot more gas into the cylinder. Not only that but you tank is huge, or you have to keep it at pressure to keep it liquid
ok, dumb question maybe but aside from 'saving the two stroke", could it just be injected before the reeds after a throttle body. Just basically for the electronic tuning of it. can the injectors push the premix without failing. small battery just enough to operate the pump and give the pcm power and the pump is pretty much half the size of a small red bull can. i thinj it can be done if the injectors can survive it. maybe add a primer button for cold starts.
Thanks for the explanation. I know the sleds run direct injection but am not 100% on how. Would an oil lubed bottom end with a 2 stroke top end with direct injection of fuel only above the exhaust port work? Or am I mental?
How about a really good, cleanable filter that goes right before the silencer. Every 5 hours you clean or replace the filter. Just install a visual light to tell you when it's time. Yellow when your close and red when it's time!
You don't have to inject fuel after the exhaust port is closed, you only have to inject it at a point in time that is close enough to exhaust port closing to prevent any unburned fuel from going out the port. The pressure wave from the pipe helps to keep fuel from getting out the port as well. FITCH (now called E-tec), Orbital, and HPDI, are all ways to direct inject a two stroke, and have been used on marine engines for almost 20 years now. Also you're skipping over Arctic Cats neat half DI half IDI setup.
I haven't skipped over anything, thats a different subject altogether that I will cover. This video can't be 2 hours long as I talk about ever system ever used.
I have a 2T myself (KTM LC2) , but I already hate the Smell without having to drive it, because a mate of me has a DT and when we ride on his bike we both stink so hard...He always smells like 2t oil, that's getting annoying quickly
You can get rid of the oil in exhaust gas on a two-stroke but then you have to build it as a Deitroit 2-stroke diesel with compressor fed air and exhaust valves....
You have just described the 2 stroke diesel, it does require a positive displacement air scavenge pump due to the lack of scavenging from the crankcase, you will have seen them called an 871 blower and used on hot rod V8 petrol engines, there they are in a supercharging mode whereas on a diesel you use them just to make the engine breath, you add a turbo to get some supercharging. Big 2 stroke diesels are widely used in large ships where they show amazingly good fuel consumption. Look up Wärtsilä RT-flex96C is a two-stroke turbocharged low-speed diesel engine Power output: 80,080 kilowatts (107,390 hp) Dry weight: over 2,300 tons Length: 26.59 metres (87 ft) Best specific fuel consumption 160 g/(kW·h) Look up what your engine does.
Question: in the case of injected 2 strokes, especially in the case of direct injection, why would you still need to run the intake through the oil? At that point, other than completely redesigning the intake process of a 2 stroke engine, wouldn't it be possible and advisable to just reroute the entire intake to avoid the oil chamber, and just have the oil system be more like a traditional 2 stroke? Or am I missing something else as to how the engine works? I'd love to find out. I mean, I know we still wouldn't have volumetric efficiency with a 2 stroke, but at least would have oil-less 2 stroke systems, which might be what revives the 2 stroke overall (or at least broadens it's use cases). I for one would love to see more 2 stroke bikes on the road again, they still have a unique sound, to me.
"why would you still need to run the intake through the oil? - 2 strokes can't 'pull a vacuum' (hate that phrase) like 4 strokes do, due to all the holes in the cylinder. Therefore, they need to 'pump' air into the engine. They the space beneath the piston to do this, and this is where the crankshaft and bearings are. They need oil and that's why.Direct injection and injectors have been used in engines for 100 years+ all diesels are injected, and always have been.
The Workshop got it, i forgot about the whole vaccuum ordeal. If thats the case, why not use an electric turbo or any other type of electronic forced induction to push air into a closed off air loop? (Im talking about for larger scale engines, like for bikes or atvs
Technically possible and have been several attempts. Pretty much all have several issues and end up with 2 major problems. One is construction of the injector itself. But the real problem is carbon residues. All workarounds still don't make it viable for the market.
They have chain saws and weed eaters that has exhaust valves i worked at a small engine repair shop and those 2 strokes with exsust valve sucked evry one broke down and it couldnt rev past 5000rpm wich defeats the purpose
Yeah, and if you were going to do that then you could add an inlet valve to increase the volumetric efficiency, then you'd pretty much have a 4 stroke lol
Bit of a weird idea here but I'm going to roll with it until you shoot me down. So motocross bikes operate on rough terrain and their suspension systems are constantly working. What if you gassed up your two stroke, basically pre-charged your fuel system with a scuba tank then bled off pressure from the action of the suspension system while riding to charge an accumulator to keep the fuel pressurized enough to make the injector function? Obviously I have no idea how much pressure is required or how much energy could be reclaimed and re-purposed while riding but it's an idea right? Shoot me down, laugh all you want but in my theory it just might work. Obviously not going to be much use on the highway but maybe it would work off road where many two strokes used to live?? Even if it just reduced the load on an external pump it could be cool? Maybe not, I'm sure you'll set me straight.
I don't really see the problem with burning a small amount of oil? I mean either you burn fuel or oil and both will come out the other end more or less the same.
They should leave the 2 stroke as is and they should play with the exhaust ( something to absorb the oil,? or separate it from the rest of the gases,? or something like the diesel exhaust fluid,?) don't be savage with the answer its late am almost asleep 😀😀🙈
It's probably been brought up before, but one could design a wet sump 2 stroke with a blower pushing in the air instead of the downward pressure from the piston, that would elimate the need for the fuel mix as the Detroit 2 stroke diesels did. The injector could be fired right as the piston covers the exhaust port preventing blow through of the fuel.
Simply check how a Rotax E-TEC is made.Problem solve.
The E-TEC is somewhat close, but still injects oil instead of using a wet sump. Instead as you say, mount a turbo wheel compressor to the crank to charge the air instead of messing with oil injection. I do like the variable size E-TEC exhaust however, that is slick.
I've seen this back in the 80's and told the engine was "killed" Using an air pump (turbo). The intake pressure pushes out the exhaust. Cycle timing is. 0deg TDC is detonation 90deg exhaust opens and relieves pressure. 110deg intake opens and the pressure removes the rest of the exhaust until 180deg. from 180deg to 360 is compression stroke. The injector can almost remain open with multiple cylinders using a throttle body method. 1 single injector vaporizing and mixing. Please try it out.
if we could direct the dangerous exhaust gases away from the pandas and towards the grey squirrels we'd be on to a winner
Definately lol
Pandas are a warning to vegetarians: they have half the brain compared to a normal omnivorous bear of the same size.
Two stroke exhaust design is black magic. It's easy to make it resonate at one frequency and it's harmonics but not across a wide frequency band.
lol hence why it isn't black magic, they don't resonate across the power band
The Workshop It'd be magic if they could.
very true - making a variable length expansion pipe isn't hard. Making one that can operate for more than 200 miles is......
And it's all extra mass to carry.
They have been doing it on boats since the 60's two cables connected to the throttle linkage and sliding expansion pipes usually found on hydro hulled boats. They slide around 4 inches and most are not sealed. Honda Racing Corporation had a system on some NSR500 racers, by adding a water tank to the bike, with a 3/4ths gallon volume, and a computer driven pump, to inject water vapor into the primary pipe. The steam created an offset of volume in the head pipe, changing its flow rate, making the engine think the exhaust system was of smaller dimension at lower rpms, for more low speed torque production, then their is the powervalve Yamaha developed which varies the exhaust port height. They are all proven tech and can last many many many miles.
I like these videos , you make it feel natural for us to watch you by swearing drawing an not staring at us constantly very good way to film vids , and easy to understand what your going on about
For the love of twostrokes, I really hope that you one day will have the fortune to drive a Yamaha SRX700 snowmobile. An inline 3 cyl twostroke. I bet you will have a hard on.
So do I
Buy an old soviet made car. They have inline three 2 strokes in them.
David Vermillion, That would be cool indeed. Just like the golfcarts with snowmobile engines. Completly insane, but fun.
those engines were sweet but a reason yamaha has went all 4 t with their snow machine engines
4t snowmobiles are heavy. The 3 cylinder twostroke engines were awesome, great torque etc. But also heavy and wont fit in the cassis. That's why all the snowmobile mfgs use 2 cylinder engines now, be it 2 stroke or 4.
You can't even compare a 15 year old sled with a new one. The difference in rideability is ridiculously large!
This guy is awesome, I could listen to him talk about engines all day.
cheers dude
Good advice about the dangers of high pressure injuries. Photos of victims are horrifying.
"diesels use a great big whacking pump" Looks like the same air conditioning pump used with gasoline engines.
So a 2T diesel is THE answer!! Haha, Love you Matt, keep up the great work.
Not for motorbikes. That's mats area of expertise.
Funny you mention 2t diesel. Ever look into old Detroit diesels? Fascinating design really, especially for their time
@@theq4602 to be fair there are some.pretty nice diesel bikes built for off road stuff. The US military bikes based off the KLR650 is amazingly nice to ride. Like REALLY nice to ride.
I got an 8v92 silver Detroit 2 stroke
The Fitch injectors used on kawasaki jetski are electric operated, there is nothing unsafe about them, only high pressure is going into the cylinder.
It does need a 40psi input, which isn't totally safe vs a 4psi carb. I believe the direct injected two stroke is the best engine ever, and totally surprised it hasn't taken over by now.
those hydrocarbons smell awesome. Also screw the pandas
LOL
Backyard Boosters fuckin oath the smell is one of my favourite things about ya 2 smokers
PANDA?
YOU SHOULD MEAN POLAR BEARS
If we had teachers at school like you back in the day i'd have paid attention.
“So, what do you want to do? Well you want to put a fuckin injector into it.”
way back in 1980 we had a Honda XL 185 four stroke and a Yamaha DT 175 which were about equal in performance and fuel economy. most 2 strokes in aircraft engines are half the CC of the four strokes. would the economy improve if they were same size but detuned with lower exhaust port roofs?
@Tobias Cat as far as i know the Etec system is s direct injection which injects fuel closer to TDC after all ports are closed. They use an oil pump to deliver oil to internals. I'm not sure why they didn't render 4 strokes irrelevant. Could be lack of public awareness to overcome the negative sentiment towards 2 strokes.
Because they are inefficient. They're volumetric efficiency is low.
@@dirtygarageguy Are you referring to the Etec?
Yes. They have a few issues.
1) low compression
2) it's a ported 2 stroke so they'll only get low VE
3) they have a limit in rpm
@@dirtygarageguy thanks. wouldn't the power to weight ratio make up for these efficiencies?
any new videos coming on your new engine design, think it was a hossak?
Nice video! I love your way to explain things, both easy to understand and enjoyable!
Air blast injection? Also what about those old IDI diesels with the antechambers on them.
From 1988-1994.5 ford bought big 7.3 liter V8 engines for their pickup trucks. (previous 4 years were 6.9 liters)
These engines were the antechamber type, with a single injector pump the size of your fist back in those days making ~190HP and ~360 ft-lbs of torque.
They had a few high pressure fuel lines running to pop off valve type injectors with springs in them that popped at about 1900 psi and these injectors are smaller than modern 4 stroke EFI injectors. A set of remanned ones can be bought for around 200.00/160 pounds.
Why not use a simple old mechanical pump like those? The pump could be TINY on a 1/2 liter two stroke. Probably finger sized (a large guys finger) if its a plunger type. Not really much more complexity.
That injection system relies on the lubricity of diesel fuel and would fail rapidly if used for injecting gasoline. It also relies on the higher viscosity of diesel fuel to 'fill' the clearances between parts creating the high pressure seal without allowing metal to metal contact.
Never laughed so much LOL "they are fucken hydro carbons going up your nose!"
Dumb question but why not have an oil injection system fed to an internally hollow crankshaft where its orifices feed the only spots needed for lubrication, squirters for the underside of the piston if need be? It resolves the need for a crankcase reservoir, retains the basic parts of a 2T engine and still can utilize direct injection.
Becaus where the crankcase is the charge pump so oil will end up in the cylinder...
@@dirtygarageguy ultimately yes, oil will almost always become a byproduct at that point, however less could be used since it would be pressured and oil fed to only the most important locations
Less is still too much. Think of it this way, 4 stroke engines like the hayabusa are failing euro 5 emissions... 2 stroke burning any oil have no chance.
@@dirtygarageguy for today's emissions mandates and regulations, sadly the 2 stroke has a short life ahead of it. It did make a comeback at one point from carb to TPI, the improvements made were substantial. What's to stop another person to redesign it to work within today's stringent requirements?
infact there is a bloke who put a 2 stroke triple snowmobile engine in a bike. trouble is he only seemed to have one gear like a scooter. it was cool though and sounded wicked
I drive a direct injected 2T moped and I can say that it is fucking great! It goes much faster than most other original mopeds! It is a Aprilia SR50 DiTech with the Aprilia engine. It makes 5hp with all the restrictions on it and everything! Unrestricted they say that it will do 70mph isch. But i can tell you that the complexity of that motor is very basic! I am only 16 and I've restored the whole thing on my own. It is much simpler than a engine with a built in gearbox. Look in to it and see for yourself ;)
I've never been so informed and amused at the same time
Worked on high pressure hydraulic systems building and testing valves ,i have seen 9000 psi just before it went bang big time really lucky not to get hurt ,but it did rain oil for a bit ,ive heard of someone looking for a oil leak on concord it used such high pressure lines that it cut his fingers off even a small pinprick could lead to amputation the only way to release oil in your flesh is by cutting around like a peeled orange.So think before you touch around fuel lines and injectors
I think your show is great specially the rants
cheers dude - and oil systems are cool but can be bloody dangerous, not a bad as air systems though.
you need to make a huge sign for that plane
I shit you not, we might have an identity of who it is. The misses great uncle flys around these parts on the weekend. I need to get the serial number off the side and ask him what plane he has. I know its a Cessna 152 but haven't read the registration. More to follow if I can get photos etc......
Not a very British solution :D
I think that would be frowned upon.
it just needs to be a big sign that says PISS OFF!
@@bavarianmonkey8326 oh I dunno the hurricane had 4 50's and it was a very british solution
that looks like an AC pump if you ask me not a diesel pump and many petrol cars are DI now
it it, "clutchless" on an dieselpump? and it uses a 6PK belt, not a timing belt...
Snowmobile engines are quite awesome. They are shrouded because of the ambient they must perform in and running them above zero is detrimental. It can be done but, serious thought on cooling is required.
Very true, the same can be said of outboards and jetskis
Yes but, both those other examples are water cooled. Had a go-kart that was powered by a snowmobile engine and had to create ducts to channel more air to the engine because of the way it was constructed. I enjoy your commentary quite a lot because you're a man's man, no b@llshit here. It's late for you there. We're 4 hours behind you.
I have never seen a Direct Injected 2-Stroke Sled (Doo E-tec, Polaris CFI, Cat C-tech) that was air cooled... Most High Power Snowmobile engines are Liquid Cooled. Air Cooled 2 stroke snowmobile engines can be used in the summer, but jetting and cooling must be planned correctly.
How about a direct injected diesel two-stroke with an Oval Zylinder :P
It’s a desiel, the fuel is designed to be burned at the top of compression and not by spark. So most of the fuel is burned and evenly spread.
Hi Matt, I know this isn't engine related but would you consider doing a video on counter steering into corners as opposed to"just" leaning?
Yes, already on the list dude - I have 2 videos in mind, 1) a demo of how its done 2) the theory behind it - matt
A longer cylinder and piston with rings on the bottom to separate crankcase oil. More moving weight, but doable.
Still goes through the ports...
Knowledgeable geezer
Matt, this chanel is bloody brilliant.
Keep the videos coming.
This might sound daft But do you think there could ever be a form of dry lubrication. Eg Graphite or some kind of ultra low friction coating in The future?
Video already done dude - just needs editing etc
He's becoming psychic!!
moly.... also heard or potassium borate recently...
Best quote ever.
Engines aren't the problem. It's the 7 f-ing billion of us that are using them.
jon doe population control. Fuck electric
Simplicity is one, but damn the sound and smell can't beat an ole two.
Also a problem with two stroke injection is pluse rate. I run a drag sled that revs to 13,500. I tried to get it on efi but the injectors wouldnt stay open after 9500rpm. You bring up formula one and they rev to 20k but the injector is only opening 10k a minute. There hasnt been much technology to make injectors work past that as 99% of engines dont need to have injectors to pluse at 200 times a second.
The trick is to not use the crankcase as the compressor: use a separate supercharger or turbocharger. That way the lubrication stuff is kept away from the combustion stuff. Then make the intake at the ports at the bottom, and the exhaust as four valves at the top. This also keeps a steady temeprature gradient along the cylinder.
Already done the video(s) on this dude
you could do it the way a 2 stroke diesel does it with an exhaust valve but just add a spark plug alongside the injector. you would obviously have to change some things like the compression could be lower. and 2 stroke diesel can be supercharger and turbocharged. you'd have to add an oil pan and sump tho cause 2 stroke diesels use a oil sump and a pressurized lubrication system instead of relying on oil in the fuel but diesel is also somewhat of a lubricant so that helps it.
2 Stroke diesels need to be supercharged emphasis on the word NEED. here - czcams.com/video/nIM0m9Z-C6o/video.html
stupid question, but what if you just put oil in the crank case, plug the transfer port on the crank case side and supercharge air into the cylinder through the transfer port? that means no oily air, no oil in the exhaust, etc. fresh air pushes out smoke, exhaust port closes, injector fires, spark, boom. sure this won't solve the problem of dispersing the gas quickly enough, but this could work for lower rpm clean burning 2 stroke. sure, now we need a supercharger but I said in the beginning it's a stupid question lol
In my experience, the FICHT Direct Injection Polaris Watercraft and Johnson/Evinrude two stroke engines run amazing. So it's been done and perfected already?
Well not quite - The E-tec voice coils have their limitations - RPM being a big one. Weightand cost being the other. E-tec is owned by BRP
I'm the guy with the aeroplane, and yes I do sit and wait for you to start recording.
Hah!
The diesel has big displacement and high compression ratio, fuel pump shouldnt be a problem on 2 stroke direct injection. Not to mention that diesel also injects in TDC.
Snowmobile engine's have direct injection and some even have turbo from factory.
They do, well they did. Evinrude went out of business and the etec injector isn't that good. I have one.
Love your channel dude.
Cheers dude and welcome to the channel - matt
the diesel pump you showed, was an AC compressor, looool
Bro if 2 stroke with direct injection does that mean i don't need to use 2T oil in the combustion chamber but the 2T oil will work as a lubricant oil with also the engine oil? or mix petrol and 2T oil in the injector injector?
Depends on the system. The etec system uses a separate oiling system but the biTech doesn't
the only thing added to a 4 stroke is a timing chain, cams, lifters, and valves... if your scared of timing and a feeler gauge just tell us
They should help emissions by porting the exhaust. The port should close when all the burnt gas is out and opens to let it out. It should help with the build up of oil and gas in the exhaust pipe
One could solve the problem of drawing power from the engine by using a battery to power the injector.
It would not be ideal for everyday use, of course, but for someone who has a ktm 200 exc or something similar to use on the weekend, a battery would probably do the job.
The problem then would be the weight of the battery (but it could be used to optimize the CoG) and the battery life. If the battery could last 90 minutes of recreational use, it would be more than enough.
If not, a small percentage of the engine's power could be used to extend the battery's life.
ok 2t is awful technically but that power band and grunt is another level to have fun with :D
You barely touched one the one undeniable advantage of 2- strokes but you did touch on it. Most backpack blowers are 2T (2- stroke) blowers and work great. A company (i think Makita) came out with a 4T (4- stroke) blower. It is actually pretty impressive. Noticeably heavier but not uncomfortably, CONSIDERABLY better fuel economy, and no more having to have 2T fuel on the jobsite. BUT, they can't run upside-down. A blower can stay upright. A chainsaw absolutely cannot. In just about any application that oil pick up isn't an issue, a 4T motor CAN produce more power more efficiently. How? A turbo. You can take a 125cc bike, increase to 183cc, turbo, and be at 40hp. You cannot get that out of a similar sized 2T. And as close to that as you can get with a 2T, let's say race built 200cc, it'll burn considerably more fuel.
For comparison. We have a Husqvarna 3120XP (120cc) chainsaw. That thing burns about 2-3gal/hr at wide open throttle. My MSX125(125cc) has slightly less power (which a cam and tune would easily fix) but averages 75mpg when i ride wide open and 115mpg IF i ride normal. If i had to guess, it would be about 1-1.2gal/hr wide open throttle. BUT, the 125cc CANNOT run upside- down. Hell, it can't even wheelie because the oil pump is the oil pick up and is in the front of the motor. So, pound for pound, with a turbo, 4T is more powerful. But, 2T cannot be replaced for chainsaws and other 2T equipment that has to run in any orientation.
Total agree with you there but this is a motorbike channel
The Workshop to touch on motorbikes, no reason for 2T anymore except nostalgia. 4T turbo would kill them. Though they have the advantage in price, the maintenance and fuel efficiency makes a turbo 4T a more desirable choice. With the exception of nostalgia of course.
Russ Jamison and you can make a race built 4T turbo that'll be faster (less HP but tons more torque). Anything is possible. But the 3120XP(120cc) is designed to run... 1000hrs without fail? Putting out 12hp. And the 3120XP has another trick: no reed valve. Stupid simple. The MSX125(125cc) is 8hp in a stock anemic tune with 14:1 air/fuel and 9.6:1 compression. But, the MSX125 cannot run much beyond 45 degrees lean angle of the motor. The 3120XP can run in any orientation.
He’s back again .... subbed lol
My 2 stroke grass strimmer will only start if I remove the spark plug and inject fuel onto the piston Replace and it starts first time and continues to do the jib. Is it the carb fuel bulb is sucking up from the fuel tank ok. any ideas
Couldn’t you have a rotary valve like ski doo had in the 90s, and have the exhaust closed until atdc then when below the exhaust the disc closes exhaust, and inject the fuel mixture when the piston is on the bottom part of its stroke?
outboards got fuel injection in the 90´s. there are many di two stroke engines. tohatsu tldi, yamaha hpdi, evinrude e tec just to name few. also snowmobiles got similar engines
What i never understand is that 1 person riding a 2T bike surely would be doing less damage to the environment in comparison to 1 person driving a 2L+ diesel or petrol 4x4 which you see daily?
Let's have a scenario here. We stop using the crankcase pump air into the cylinder and instead use some form of forced induction. This would mostly fix the oil issue from what I understand. Then, we use a valve on the exhaust port to stop the fuel-air mix from escaping with the exhaust. Or, we find some unobtanium-based way to fix the problems of the two stroke engine. My question is, is there a benefit over four stroke engines created by having twice the number of power strokes in the same number of reciprocating movements of the piston?
To those who might think Matt might be over exaggerating with the dangers of high pressure injectors... Try look up Hydraulic Injection Injury... Not for the faint of heart mind you.
It is a real danger and if you EVER get a "stingy" shot GO TO THE ER ! You might not be able to see it, but that does not mean you have not been hurt.
BTW great channel Matt ;-) Meet you here about a week or two ago and i am freaking hooked :-P
Cheers for the comment dude and welcome to the channel - matt
They are only amputating....if you are lucky.
But the system is only under pressure when the engine is running. The moment it's stopped that high pressure is gone so the danger to a person servicing it is 0....unless he's trying to take apart a running engine in which case he has many other hazards to consider.
@dirtygarage guy. How about doing a video on Strato charged two stroke technology as patented by Komatsu and as used on most 2 stroke outdoor power equipment today?
whats about a combination of a carburettor and injection. the carb would give a very lean gasolin oil mixture... and the main gasolin regulation takes place with an injector... some thoughts: the carb needs to handle a seperate oil regulation to give more oil on high rpms, why dont we put an injector in the transfer port? , i think powerloss on an all mechanical fuel pump with fuel regulators wouldnt be such a big impact.
and yeah the carb needs some sort of a throttlebody function
I wish manufacturers would embrace "responsible modification" or something and tell people how to do it safely and without fucking up the engine. Im into snowmobiles personally, but I think you guys in the motorbike world have the same issue as us where the companies only want to cover their ass from liability
What about a wet sump just like in four strokes. I know the problem with how are you gonna get air into the cylinder but ive been thinking about turbos. Since the injection is after every port is closed you wouldn't need expantion chambers and backflow and all that stuff so a turbo wont fuck it up like it would with a carbourated engine. And if the turbo would steal too much power an electric one wouldn't need much power since it only has to make like one bar. Im not thinking of forced induction but while the piston closes the inlet port it builds up pressure and as soon as it opens it would flush out the exhaust and replace it. The upper part of the cylinder might be hard to flush but then again it is as you said with port geometry
Jetski engine in a bike would be fun but you'll have trouble cooling it because they run cold water, total loss cooling systems. Snowmobile engine would be the way to go.
It's not that hard to sort out, jet ski or snowmobile
Aprilia did a direct injection 2 T 50 cc with an electric fuel pump. It was shite and a right twat to de-restrict.
poor thumbelina and her mates 😢. I agree with yourself that it's just not worth the hassle of all the research and development when 4 strokes have moved the game on so far. I rode behind my dad's 2 stroke for half an hour and I had a headache and felt like something was stuck in my throat. But still have massive respect for them. Just don't want them to make a comeback cos it won't be like it used to be.
Great show, enjoy your style,
Keen to hear what you think of the Tohatsu low pressure fuel injection two stroke outboard ~40 hp and larger.
I do like the smell of tts
Kind regards
Donald New Zealand
Welcome to the channel dude - do any of you kiwis have jobs? There's a load of you lot on here lol
Run it on Castor oil and alcohol that makes two strokes green. Who would have thought. .
What if your fuel was already a gas, like propane? Would that make a difference in how it's mixed in the cylinder?
Gas is a lot less dense that liquids. So you have to pump a lot more gas into the cylinder. Not only that but you tank is huge, or you have to keep it at pressure to keep it liquid
ok, dumb question maybe but aside from 'saving the two stroke", could it just be injected before the reeds after a throttle body. Just basically for the electronic tuning of it. can the injectors push the premix without failing. small battery just enough to operate the pump and give the pcm power and the pump is pretty much half the size of a small red bull can. i thinj it can be done if the injectors can survive it. maybe add a primer button for cold starts.
Thanks for the explanation. I know the sleds run direct injection but am not 100% on how.
Would an oil lubed bottom end with a 2 stroke top end with direct injection of fuel only above the exhaust port work? Or am I mental?
How about a really good, cleanable filter that goes right before the silencer. Every 5 hours you clean or replace the filter. Just install a visual light to tell you when it's time. Yellow when your close and red when it's time!
You don't have to inject fuel after the exhaust port is closed, you only have to inject it at a point in time that is close enough to exhaust port closing to prevent any unburned fuel from going out the port. The pressure wave from the pipe helps to keep fuel from getting out the port as well.
FITCH (now called E-tec), Orbital, and HPDI, are all ways to direct inject a two stroke, and have been used on marine engines for almost 20 years now.
Also you're skipping over Arctic Cats neat half DI half IDI setup.
I haven't skipped over anything, thats a different subject altogether that I will cover. This video can't be 2 hours long as I talk about ever system ever used.
Do you have a video on main bearing lubrication with DFI two stroke engines? If so, would you you provide the title? Thanks. Great videos.
Why can' they fit an exhaust poppet valve to these 2 stroke engines, like marine 2 stroke engines?
Awesome channel man! Question: Do you see a future for enduro/mx 2 stroke motorbikes after the Euro 6 regs come into effect?
The Euro emissions lag behind for 'recreational vehicles' so they still have some room to breath so to speak.
Also, how would you get the fuel pressure up starting it if it's belt driven? Wouldn't that be a kick to the nuts painful?
Didnt aprilia did this on SR50 di tech ?
that's TPI not direct into the head
It looks like it's ditectly oj the cylinder head to me
I have a 2T myself (KTM LC2) , but I already hate the Smell without having to drive it, because a mate of me has a DT and when we ride on his bike we both stink so hard...He always smells like 2t oil, that's getting annoying quickly
Turn in your man card and buy a 4 stroke scooter.
i have invented a piston forced induction oval cylinder two stroke with lots of valves do you wanna talk about it
which is much more faster carb.2 stroke or carb.4 stroke? or D.I.2 stroke vs D.I. turbocharge 4 stroke? i hope i could have a great answer for this
give it a wet sump and slap a supercharger on it, solves the oils burn and produces EVEN MORE POWER
You can get rid of the oil in exhaust gas on a two-stroke but then you have to build it as a Deitroit 2-stroke diesel with compressor fed air and exhaust valves....
Another episode of sounds great doesn't work.
But exhaust valve might still be a good idea, if i may say
Why not have a "4-stroke crank" with premixtured charge pressured into a 2-stroke design.
Video coming soon dude
You have just described the 2 stroke diesel, it does require a positive displacement air scavenge pump due to the lack of scavenging from the crankcase, you will have seen them called an 871 blower and used on hot rod V8 petrol engines, there they are in a supercharging mode whereas on a diesel you use them just to make the engine breath, you add a turbo to get some supercharging. Big 2 stroke diesels are widely used in large ships where they show amazingly good fuel consumption.
Look up Wärtsilä RT-flex96C is a two-stroke turbocharged low-speed diesel engine
Power output: 80,080 kilowatts (107,390 hp)
Dry weight: over 2,300 tons
Length: 26.59 metres (87 ft)
Best specific fuel consumption 160 g/(kW·h)
Look up what your engine does.
E85 Direct injection
Gear/shaft drive 2ndary pump in head
Twin lubrication port lo and high head
...
Fuckin great fuckin vid
Very fuckin informative
How does it oil the crank box thingo
love the race fuel in a 2cycle.
Question: in the case of injected 2 strokes, especially in the case of direct injection, why would you still need to run the intake through the oil? At that point, other than completely redesigning the intake process of a 2 stroke engine, wouldn't it be possible and advisable to just reroute the entire intake to avoid the oil chamber, and just have the oil system be more like a traditional 2 stroke? Or am I missing something else as to how the engine works? I'd love to find out.
I mean, I know we still wouldn't have volumetric efficiency with a 2 stroke, but at least would have oil-less 2 stroke systems, which might be what revives the 2 stroke overall (or at least broadens it's use cases). I for one would love to see more 2 stroke bikes on the road again, they still have a unique sound, to me.
"why would you still need to run the intake through the oil?
- 2 strokes can't 'pull a vacuum' (hate that phrase) like 4 strokes do, due to all the holes in the cylinder. Therefore, they need to 'pump' air into the engine. They the space beneath the piston to do this, and this is where the crankshaft and bearings are.
They need oil and that's why.Direct injection and injectors have been used in engines for 100 years+ all diesels are injected, and always have been.
The Workshop got it, i forgot about the whole vaccuum ordeal. If thats the case, why not use an electric turbo or any other type of electronic forced induction to push air into a closed off air loop? (Im talking about for larger scale engines, like for bikes or atvs
Someone who swears more than me
Do you think 2t engine military applications are reasonable? Since no worry about emission stuff vs cheaper & easy to fix.
Being in the REME the easy to fix bit isn't an issue. But that's a point I'm going to bring up soon, real soon, as in tomorrow lol
The Workshop oh thanks a lot mate, waiting to see it.
This maybe a dumb question but why can't already atomized change be injected into the head?
Mental question but ok. Will answer this is a future video - matt
Technically possible and have been several attempts. Pretty much all have several issues and end up with 2 major problems. One is construction of the injector itself. But the real problem is carbon residues. All workarounds still don't make it viable for the market.
They have chain saws and weed eaters that has exhaust valves i worked at a small engine repair shop and those 2 strokes with exsust valve sucked evry one broke down and it couldnt rev past 5000rpm wich defeats the purpose
ok sir
What about throttle body injection instead of directly in the head? In my little brain that would work
That is already being done, and it improves emissions a little, but not enough to keep up with the ever tightening demands for greener vehicles.
just a thought that popped up in my head, couldn't you just use exhaust valves on 2t and fix the whole issue with fuel flying into your exhaust?
Yeah, and if you were going to do that then you could add an inlet valve to increase the volumetric efficiency, then you'd pretty much have a 4 stroke lol
Bit of a weird idea here but I'm going to roll with it until you shoot me down. So motocross bikes operate on rough terrain and their suspension systems are constantly working. What if you gassed up your two stroke, basically pre-charged your fuel system with a scuba tank then bled off pressure from the action of the suspension system while riding to charge an accumulator to keep the fuel pressurized enough to make the injector function? Obviously I have no idea how much pressure is required or how much energy could be reclaimed and re-purposed while riding but it's an idea right? Shoot me down, laugh all you want but in my theory it just might work. Obviously not going to be much use on the highway but maybe it would work off road where many two strokes used to live?? Even if it just reduced the load on an external pump it could be cool? Maybe not, I'm sure you'll set me straight.
how about a oil sump 2 stroke(like a 4 stroke cranckcase) with a valve in the intake (no transfer ports) and a supercharger running 100% straight gas
Are there really engines that consistently make two to five hundred atmospheres of pressure? Isn't 1 bar 1 atomosphere (14.7 psi)
1 bar is 14.5 psi - where do you guys get 14.7 from?
Do you get more power if u use less oil in a 2 stroke
No
if a diesel injector squirts in your face, just wash the diesel of with a towel ;) its not dangerous
I don't really see the problem with burning a small amount of oil? I mean either you burn fuel or oil and both will come out the other end more or less the same.
I mean people just think it's so bad for nature because they can see the exhausts 😂
+Christoffer Brandel I agree and diesel emits it's shit onto floor we walk on.
They should leave the 2 stroke as is and they should play with the exhaust ( something to absorb the oil,? or separate it from the rest of the gases,? or something like the diesel exhaust fluid,?) don't be savage with the answer its late am almost asleep 😀😀🙈
It absolutely could be done, but it would nullify the advantages of a 2 stroke engine.