2-stroke strikes back on 4-stroke "greenwash"?
- Thread starter 4Z
- Start date
Good Read!!
Ace
Ace
C
cableguy
Member
Pitching it as the ‘two-stroke Desmosedici’ - a factory GP machine for public – the bike will feature a new injected 500cc V4 producing over 200bhp, in an evolution frame based on the gorgeous Ilmor X3. Counter-rotating crankshafts will kill vibration and gyroscopic resistance to turning >NICE<
great read, very interesting.... take that Yamaha... lol!
2T vs 4T
Watch this video and you will see why!
http://www.youtube.com/watch?v=_-7I00cZUE0&feature=channel_page
Watch this video and you will see why!
http://www.youtube.com/watch?v=_-7I00cZUE0&feature=channel_page
MX bikes and sleds are two different things. I've owned 2 stroke MX bikes and never had one burn down. That certainly hasn't been my experience with 2 stroke sleds.
Another aspect is MX bikes are ridden in dirt and dust and are run through a manual gear box. I doubt you'll hear very many MX guys admit they downshifted in the air, landed off a jump and over revved their motor on decompression. Nope, it's just the POS 4-stroke's fault. These type of failures and environmental conditions are not issues for sleds.
I like my 4 stroke sled. If a guy likes a 2-stroke, then great! Buy and ride one. There are plenty to choose from. Unlike MX, the 4-stroke sleds have not been shown to have any significant performance advantages over the 2-strokes for either sno-x or XC racing. In MX, the 4-stroke bikes were an advantage over the 2-strokes due to the controllability and smoothness of the power. I don't think there was any great conspiracy. The OEM's simply provided what their customers desired. I'll be curious to see how reliable a 2-stroke MX bike is when it comes equipped with all sorts of electronics and emissions equipment necessary to make it as clean as a 4-stroke. If this was the way of the future, the automakers would have went this route. Engines are heavy and if a car maker could not only save weight (for better MPG) on an 2-stroke engine but also cut the production costs due to it being more simple, they would have done it.
Another aspect is MX bikes are ridden in dirt and dust and are run through a manual gear box. I doubt you'll hear very many MX guys admit they downshifted in the air, landed off a jump and over revved their motor on decompression. Nope, it's just the POS 4-stroke's fault. These type of failures and environmental conditions are not issues for sleds.
I like my 4 stroke sled. If a guy likes a 2-stroke, then great! Buy and ride one. There are plenty to choose from. Unlike MX, the 4-stroke sleds have not been shown to have any significant performance advantages over the 2-strokes for either sno-x or XC racing. In MX, the 4-stroke bikes were an advantage over the 2-strokes due to the controllability and smoothness of the power. I don't think there was any great conspiracy. The OEM's simply provided what their customers desired. I'll be curious to see how reliable a 2-stroke MX bike is when it comes equipped with all sorts of electronics and emissions equipment necessary to make it as clean as a 4-stroke. If this was the way of the future, the automakers would have went this route. Engines are heavy and if a car maker could not only save weight (for better MPG) on an 2-stroke engine but also cut the production costs due to it being more simple, they would have done it.
I like both the 2 and 4 stroke engines.. but to be competitive in motorcross the 4 stroke got a hugh Cc increase..run comparable Cc's and the 2 stroke rules...
Why is that?
P
powderlites
Well-known member
2 stroke/4 stroke
Yamaha in the 1970's had a prototype V4's road race bike motors that were put away after making a few laps as they were way to far ahead of competition. They had 2 cranks and sound the same.
At that time they were considered too much HP.
Then in the 1980's Yamaha had RZ500R V4 twins cranks
Suzuki had a 3 cly 50 or 60cc road race motor also never put into production as it would lap the competition.
Yamaha Vmax4 motor came from TZ 700 750cc road race engine.
Poor video and how long will 2 stroke last?
I think most guys try a 4 stroke for reliability and long life of no worries of engine failure.
If we only knew how many motors have never made it to market?
Single and double cyl motors with no crank shaft?
Long cylinder with two pistons on each end and accenteric shaft etc.
Very big torque compared to crank and rod motors.
Competition is always good for end user.
Just my 2 cents worth.
Yamaha in the 1970's had a prototype V4's road race bike motors that were put away after making a few laps as they were way to far ahead of competition. They had 2 cranks and sound the same.
At that time they were considered too much HP.
Then in the 1980's Yamaha had RZ500R V4 twins cranks
Suzuki had a 3 cly 50 or 60cc road race motor also never put into production as it would lap the competition.
Yamaha Vmax4 motor came from TZ 700 750cc road race engine.
Poor video and how long will 2 stroke last?
I think most guys try a 4 stroke for reliability and long life of no worries of engine failure.
If we only knew how many motors have never made it to market?
Single and double cyl motors with no crank shaft?
Long cylinder with two pistons on each end and accenteric shaft etc.
Very big torque compared to crank and rod motors.
Competition is always good for end user.
Just my 2 cents worth.
"Ricardo’s 2100cc 2/4SIGHT experimental engine is able to switch from 2-stroke to 4-stroke operation. It uses a 2-stroke cycle to meet demands for high torque and 4-stroke for constant-throttle running"
there you are, the best of both worlds.
Does anyone know how much it costs to freshen up a late model, high reving 4 stroke motor? When the seats are pounded into the head?
KTM's top seller is the 300 2stroke.
(just stirring the pot)
there you are, the best of both worlds.
Does anyone know how much it costs to freshen up a late model, high reving 4 stroke motor? When the seats are pounded into the head?
KTM's top seller is the 300 2stroke.
(just stirring the pot)
Most of the reliability issues related to 2 stroke burn down are traced back to lubrication issues.
The theory was that by pulling the fuel/oil mixture into the crank case, hopefully that would coat the internal bearings and cylinders to keep the engine from failing.
Well, within that crank case where the fuel mixture is bouncing around, there were pockets of calm areas wher ethe mixture would not reliably get to.
Too much oil over here, and not enough oil over there typically meant that sooner or later the engine would fail much faster than an oil bath four stroke.
Add to it a couple of other things. Jetting for example. You jet wrong and you are too fat or too lean. Obviously lean makes for an unhappy engine from a longevity standpoint.
Another is detonation. Until recently there was nothing to detect it, and nothing to help with the condition.
All the above is changing for the better. Injecting oil at specific points into the crank case using computer modeling makes for a significant change for the better onhow the oil gets distributed into the engine. Oil useage/smoke/spark plug fouling are down to almost zero.
Computer control eliminates the detonation issues as well.
Take all of this together, and put two stroke technology against a naturally aspirated four stroke, and you can keep your four stroke as far as I am concerned.
On this site, two strokes are not compared to four strokes. Two strokes are compared to TURBO four strokes, or supercharged four strokes.
If your a point and shoot guy who has to be the highest up the hill, then you will cheer for turbo four strokes. If you like to boondock in tight places, like to explore, and dont feel the need to pull out an comparatively heavy sled, then two strokes will get your attention.
I can't wait until I see a reliable factory two stroke turbo set up........
Until you have a few years of two stroke proven reliability without phrases like "I burned down again" or "I lean seized this morning", four strokes will remain the reliablity kings.
The theory was that by pulling the fuel/oil mixture into the crank case, hopefully that would coat the internal bearings and cylinders to keep the engine from failing.
Well, within that crank case where the fuel mixture is bouncing around, there were pockets of calm areas wher ethe mixture would not reliably get to.
Too much oil over here, and not enough oil over there typically meant that sooner or later the engine would fail much faster than an oil bath four stroke.
Add to it a couple of other things. Jetting for example. You jet wrong and you are too fat or too lean. Obviously lean makes for an unhappy engine from a longevity standpoint.
Another is detonation. Until recently there was nothing to detect it, and nothing to help with the condition.
All the above is changing for the better. Injecting oil at specific points into the crank case using computer modeling makes for a significant change for the better onhow the oil gets distributed into the engine. Oil useage/smoke/spark plug fouling are down to almost zero.
Computer control eliminates the detonation issues as well.
Take all of this together, and put two stroke technology against a naturally aspirated four stroke, and you can keep your four stroke as far as I am concerned.
On this site, two strokes are not compared to four strokes. Two strokes are compared to TURBO four strokes, or supercharged four strokes.
If your a point and shoot guy who has to be the highest up the hill, then you will cheer for turbo four strokes. If you like to boondock in tight places, like to explore, and dont feel the need to pull out an comparatively heavy sled, then two strokes will get your attention.
I can't wait until I see a reliable factory two stroke turbo set up........
Until you have a few years of two stroke proven reliability without phrases like "I burned down again" or "I lean seized this morning", four strokes will remain the reliablity kings.
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Didn't we already get the Ski-Doo 600 E-Tec? Not exactly the same as the Orbital system, but based on the Evinrude system.
Yep, and that is a huge step in the right direction. Now take that technology and apply it to the 800 motor (Which I suspect they are doing)
I'm sure they are trying, but the limit is the amount of fuel the current generation of injectors can supply. It is adapted from the outboard system, where they don't have to run high RPM. I'd be willing to bet you don't see many (if any) successful 600 E-Tec turbos, or any 800 E-Tec motors until they develop the next iteration of the injector.
Really interesting article.. Funny how when they compare same cc engines that the 2stroke can be made very similar to a 4 stroke. I wonder how many snowmobilers would like there 1200 watercraft motors producing the same output as the skidoo 1200 4strk stock?? I don't know about that one... That would make your 800cc engine put out the same as like a 500 cc..
Lots of cool technology coming out for 2 strokes, but isn't the same stuff out there for 4 strokes too? Variable compression ratio's, HCCI engines...
I think the last 2 stroke I heard about was in a Dodge Neon.
Interesting that Orbital is in on the 2strk fun. Weren't they the ones that programmed the Cannondale fuel injection system?
Lots of cool technology coming out for 2 strokes, but isn't the same stuff out there for 4 strokes too? Variable compression ratio's, HCCI engines...
I think the last 2 stroke I heard about was in a Dodge Neon.
Interesting that Orbital is in on the 2strk fun. Weren't they the ones that programmed the Cannondale fuel injection system?
Wouldn't piggy back injectors solve the issue anyways? Street bikes already have dual stage injectors, as that seems to be the best way to get low rpm drive ability with high rpm horsepower.
The article states that these 2-strokes are in a mild state of tune to prevent the peaky powerband of conventional 2-stroke engines. This is done to make the tech more generally applicable for people who aren't as willing to do regular maintenance as most people in snowmobiling are.
Have you seen a picture of the 600 E-Tec head? There's not enough room to have two injectors and a spark plug. Not to mention the combustion chamber geometry changes required. The street bikes don't have to inject straight into the combustion chamber, they've got lots more room to play with.
Have you seen a picture of the 600 E-Tec head? There's not enough room to have two injectors and a spark plug. Not to mention the combustion chamber geometry changes required. The street bikes don't have to inject straight into the combustion chamber, they've got lots more room to play with.
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