Two Stroke Motocross
Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: SachsGS on April 25, 2011, 04:23:20 PM
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Latest issue of Dirt Bike magazine has an excellent article on the history of the Honda CR250R and guess what? Rumours of a new CR250R! (Don't kill the messenger :-X).
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(http://i56.tinypic.com/309r1a8.jpg)
going to check it out now.
http://mail.dirtrider.net/forums3/showthread.php?t=179896 (http://mail.dirtrider.net/forums3/showthread.php?t=179896)
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If it's true, it will probably be the fastest 250 ever made (stock)
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There was a topic of someone else on here, who talked to a guy at the track (can't remember who)
who also said there was a new CR250 in the making...
Rumors of this new 2 Stroke Honda CR are growing fast!
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I have had two honda's in the past, i wasnt really impressed. When i was lighter the 125 worked pretty good for me, and the other honda was a 4 stroke, but as you can tell by my screen name, im pretty loyal in my brand
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You should know better then that Sachs. ;D
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i told ya not to doubt me!! :P haha :D
and it was lance smail who told me about it.
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I'll believe it when I see them on the showroom floor. It would be a really good thing, all the Jap sales are falling like a leaves in winter. They better do something, cause I don't know many guys that can afford to ride a modern four stroke. And I doubt they'll let the Europeans take over. eventhough that wouldn't be a bad thing
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What was the rumor exactly or what did it say?
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That Honda is developing a fuel injected 2012 CR250r
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Itd be direct injection right?
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Yes. :D
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ORIGINAL WTF BOOM (http://www.youtube.com/watch?v=hwVyXgbaXHs#)
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http://www.vitalmx.com/forums/Moto-Related,20/Honda-rumor-from-dirtbike-mag,1216382 (http://www.vitalmx.com/forums/Moto-Related,20/Honda-rumor-from-dirtbike-mag,1216382)
http://www.thumpertalk.com/forum/showthread.php?t=951487 (http://www.thumpertalk.com/forum/showthread.php?t=951487)
a CR300 would be awesome!
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Haha yeah sorry I meant DI
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I wouldn't mind if the european 2 Strokes would take over.
Heck, every major /scramble/offroad/enduro event is beiing won by a 250 or 300 KTM Husaberg or GasGas.
But it would suprise many people in the end, because the no.1 player in the buisines still keeps
preaching this overweight 4 stroke stuff...
Anyways, rumours are rumours. And i would really like to see Honda eating their own words.
These days, i believe it as soon when i see it!
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I still say, when Donkeys fly. But Honda loves to win.
(http://www.suprmchaos.com/polly-holliday1b_alice_moz_mam.jpg)
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Honda has always been about being #1 no matter what. I believe they would eat crow everyday for breakfast lunch and dinner to be at the top of the sales chart again. Especialy since new 4 stroke sales are plummeting. I think they might reintroduce the CR line with an X model as well. And with all the hope in my little black heart, Suzuki and Kawasaki will follow suit with revamped RM, KX ,RMZ and KDX models.
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That would be awesome indeed!
For all of the big 4 to make a 2 stroke woods/offroad bike! And 2 stroke MX line up.
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That would be awesome indeed!
For all of the big 4 to make a 2 stroke woods/offroad bike! And 2 stroke MX line up.
KTM is one of the Big 4 now. 1 has fallen.
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Personally, I've considered KTM a part of the big# for a while now.
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Personally, I've considered KTM a part of the big# for a while now.
So I guess Husky is part of that too then? I can't remember, are they built now buy KTM? Then all we need is gas gas and TM to start kicking butt and no need for Jap bikes anymore.
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No, husky is owned by BMW. AMA has set it up for mainly jap bikes(Monkey see, Monkey buy), so run any European bike other than KTM, and its considered cheating. Kind of like showing up at a nascar race with a long body Porsche..
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Does anybody know which jap company fell out of the big 4?
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Kawasaki.They've never been part of the big anything anyway :D ;)
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not true, Suzuki has a worse track record with a full 30 years of sucking vs. Kawasaki with just 10 years...
Tri-Z 250, ATC250R, Tecate 250, and whats missing?
YZ/IT490, WR500, CR500, KX500, and whats missing?
TRX250R = Win
Banshee = Win
KXT 250R = Fail-ish
LT250R = Fail
LT500R = Fail
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Tell that to Mitch Payton. :P
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not true, Suzuki has a worse track record with a full 30 years of sucking vs. Kawasaki with just 10 years...
Tri-Z 250, ATC250R, Tecate 250, and whats missing?
YZ/IT490, WR500, CR500, KX500, and whats missing?
TRX250R = Win
Banshee = Win
KXT 250R = Fail-ish
LT250R = Fail
LT500R = Fail
Yeah, my people say its suzuki. Sales have been horrible, maybe why they are looking at 2 strokes? I always wondered why the LT500R failed, That had to be a freakin monster. LOL. I want a Banshee motor to put in a street bike.
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not true, Suzuki has a worse track record with a full 30 years of sucking vs. Kawasaki with just 10 years...
Tri-Z 250, ATC250R, Tecate 250, and whats missing?
YZ/IT490, WR500, CR500, KX500, and whats missing?
TRX250R = Win
Banshee = Win
KXT 250R = Fail-ish
LT250R = Fail
LT500R = Fail
Yeah, my people say its suzuki. Sales have been horrible, maybe why they are looking at 2 strokes? I always wondered why the LT500R failed, That had to be a freakin monster. LOL. I want a Banshee motor to put in a street bike.
The Banshee motor came from a street bike.
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not true, Suzuki has a worse track record with a full 30 years of sucking vs. Kawasaki with just 10 years...
Tri-Z 250, ATC250R, Tecate 250, and whats missing?
YZ/IT490, WR500, CR500, KX500, and whats missing?
TRX250R = Win
Banshee = Win
KXT 250R = Fail-ish
LT250R = Fail
LT500R = Fail
Yeah, my people say its suzuki. Sales have been horrible, maybe why they are looking at 2 strokes? I always wondered why the LT500R failed, That had to be a freakin monster. LOL. I want a Banshee motor to put in a street bike.
The Banshee motor came from a street bike.
The rz 350 if im not mistaken
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Suzuki hasn't been doing well in North America but,surprisingly, are the top brand in India. Volkswagen just bought a big chunk of Suzuki.
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Tell that to Mitch Payton. :P
Wait until next year and see what team Payton is running :)
I think Suzuki's biggest problem is they don't know how to name a bike :D.Cruisers,street and quads etc.BK? What the H is that?Burger King?
I think all their names suffer from a poor translation.Oh well,at least they're "Way of Life" ::)
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Ford & Monstery are both correct, All the banshee motor is, is a tuned down non power valve rz350 motor. Banshee stock 38-40hp, rz350 55hp or so. I thought suzuki problems were in the "Engineering a proper tranny department." ;D
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I thought suzuki problems were in the "Engineering a proper tranny department." ;D
I know all about that.
At least they know how to make a bike handle.
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This might be alittle off but they did stop producing the crfx's
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I believe they are still making them, however nothing has been touched since 09.
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they have a 2011 crf 250x and 450x sitting on floor at my honda dealership.$8,700 & $9,500 :o
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LOL, for older bikes to. I mean who would waste money on old technology, oh wait, the yz250...oops
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I'll sell my left nut if Honda bring out a 'you beaut' 'whizz bang' new CR250r........ :D
I would be extremely excited if they but, i LOVE Honda CR250's........ ;)
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Idk, when ever Honda comes out with something new they usually have problems. Might wait a couple years for the finished product ;D
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If they do, I think we need to have a 2012 Honda CR250r vs 2012 TM250 test ;)
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Direct Injection sounds cool, but I don't know.. I still like the idea of brass and reeds. I see it as part of the experience of owning a two-stroke - like mixing gas and oil. I think it would take a lot of fun out having to plug in an overpriced tuner or pull out my laptop.
Now if it was a mechanical DI,.. like old mechanical FI.. then we may be onto something ;)
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Running with no pipes!
EFI Yamaha Banshee First Start (http://www.youtube.com/watch?v=e1WHVVT6d9c#)
with pipes
EFI Yamaha Banshee #2 (http://www.youtube.com/watch?v=EWfHhCeD6uk#)
EFI rz500
http://www.winsto.net/projects/index.php?blog=5 (http://www.winsto.net/projects/index.php?blog=5)
http://www.bigboremotors.com/parts/yamaha-banshee.html (http://www.bigboremotors.com/parts/yamaha-banshee.html)
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a 2012 cr250 would prob be the sickest 2 stroke ever made but i still would swtich from my euro made bike back to jap bikes or at least not for now anyways if it comes out i would give it 3 or 4 years before i bought one just to make sure everything on it is good and not slaped together since prob not that many people working at honda factories ever enen remember making a 2 stroke bike
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Indeed.
Wait at least 2 or 3 years for them to sort out the bugs.
But it's a great rumour without doubt... :)
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Honda still employs all it's 2-stroke engineers. They are too valuable to let go. I won't hold my breath for Darth Honda to produce a new 2-stroke. Not atleast until they are getting spanked in the marketplace when DFI 2-strokes are the norm (or atleast more common). The only hope for 'something different' comes from Yamaha. Their MC division might just be small enough.
And not to worry about your 4T investment. Honda sits on the BoD in both the AMA and FIM. There is little or no chance of a Jedi DFI-2T becoming a regular winner in the pro class. The Evil Empire won't let it.
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Why would it have to be a DFI 2 stroke. What's so exciting about DFI 2 strokes?
Nothing's exciting about them if you ask me. The 2 stoke line from Husaberg and the KTM150 are way more exciting than some neutered, phseudo 2 stroke with a computer controlled faux power curve.
The real 2 strokes we have now are exciting race machines. I'm not all hyped up to start moving into the boring catagory presently occupied by the fuel injected 4 stroke dirt conveyors being marketed to suckers now in place of motocross bikes....
No thanks hippies... You can keep that gargage!
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Why would it have to be a DFI 2 stroke. What's so exciting about DFI 2 strokes?
Nothing's exciting about them if you ask me. The 2 stoke line from Husaberg and the KTM150 are way more exciting than some neutered, phseudo 2 stroke with a computer controlled faux power curve.
The real 2 strokes we have now are exciting race machines. I'm not all hyped up to start moving into the boring catagory presently occupied by the fuel injected 4 stroke dirt conveyors being marketed to suckers now in place of motocross bikes....
No thanks hippies... You can keep that gargage!
The only reasons why I personally bring up DI is the following: First, people who switched to 4 strokes, always say they couldn't jet their bikes. Of course, that is on the crappy owner. But to make things work really well for the general population, make it easy. So no jetting with that. Second, emmission bs that I heard over and over, but then talked directly to Whitlock and Janson and both said, had no real bearing. Just hearsay that got pushed. Gee, wonder who started it. 3rd and finally, to make a 2 stroke run smooth all the way up, like a 4 stroke, or make it a fire breathing dragon. You can adjust DI more.
That being said, I personally like the carb more. But I'm a tuner, so I can adjust them and make them run how I want.
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DI would just be a gadget to increase selling price and raise part replacement costs, dealer service frequency, and BS the masses into thinking they cleaned up the emissions on a bike, that when jetted properly, run cleaner than 4 strokes. They have the masses thinking if you can see the exhaust it's bad. Truth be told, the smoke you see from a 2 stroke is simply moisture from the oil, it is too dense to rise into the atmosphere, is only present during warm up, if the bike is jetted properly, and has less Co, than a fourstroke. And get this, if you are using castor or bean oil, is not carcinogenic, it is actually good for the earth, :o.
This is the same type of scapegoating, misrepresentation, bold face lying, and typical Corporate Snow(shit) Storm, that is responsible for a certain plant ;), that can produce 100s of products such as fuel, oil, paper, plastic, cloth and other textiles, has medicinal properties, makes you feel good, is a bi annually renewable resource, and has been growing naturally on this planet long before our viral asses showed up and started f'n it up.
And it is true, you can make a 2 stroke run smooth through it's entire range of throttle just like a four stroke. It's called a fly wheel weight.
The reason that the jap manufacturers build them to "hit" in a certain part of throttle range is because they are purpose built for moto x and that is were they should be ridden.
The problem lies in that
1. the majority does not posses the talent or ability to ride in that part of the power.
2. the owner is using said machine for purpose other than MX or SX
This is where Honda was with it's last run of dueces seeming to be lack luster, knowing that the owner would tune it to thier liking with the abundance of after market products, they built a solid platform for which to start. The yamaha dueces are the same way, smooth power without alot of rip out your arm hits in the power range.
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In theory a DI 2T would inject into the combustion chamber after the exhaust port is closed resulting in less "hit" and a whole lot more low speed torque.If you look at the numbers DI snowmobiles and outboards are producing I'd take a DI 2T dirt bike any day. ;D
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I'm not saying that DI is a bad thing, simply that it sounds like it's going to be a bigger headache than jetting. With a fuel pump, o2 sensors, tranny sensors. ignition gizmos and what not. I'm happy with just my tool box. FML if I'm going to have to drag a laptop and some crazy assed connector set up too. I'd end up spending all day in the TSM forum instead of actually working on my bike or riding. lmao
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LOL, for older bikes to. I mean who would waste money on old technology, oh wait, the yz250...oops
Oh no,not the old technology YZ thing again. :o I guess the TM,Gasgas,husky,KTM etc have all the new 2t technology.I hear the difference is...er....um...... ::)
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Why would it have to be a DFI 2 stroke. What's so exciting about DFI 2 strokes?
Nothing's exciting about them if you ask me. The 2 stoke line from Husaberg and the KTM150 are way more exciting than some neutered, phseudo 2 stroke with a computer controlled faux power curve.
The real 2 strokes we have now are exciting race machines. I'm not all hyped up to start moving into the boring catagory presently occupied by the fuel injected 4 stroke dirt conveyors being marketed to suckers now in place of motocross bikes....
No thanks hippies... You can keep that gargage!
exactly! who needs DI. not me i like my carb just fine
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LOL, for older bikes to. I mean who would waste money on old technology, oh wait, the yz250...oops
Oh no,not the old technology YZ thing again. :o I guess the TM,Gasgas,husky,KTM etc have all the new 2t technology.I hear the difference is...er....um...... ::)
Well, I just read a comparison between the 250sx and the yz250. Apparently the yz handles better while the KTM rapes it. ;D
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Why would it have to be a DFI 2 stroke. What's so exciting about DFI 2 strokes?
Nothing's exciting about them if you ask me. The 2 stoke line from Husaberg and the KTM150 are way more exciting than some neutered, phseudo 2 stroke with a computer controlled faux power curve.
The real 2 strokes we have now are exciting race machines. I'm not all hyped up to start moving into the boring catagory presently occupied by the fuel injected 4 stroke dirt conveyors being marketed to suckers now in place of motocross bikes....
No thanks hippies... You can keep that gargage!
exactly! who needs DI. not me i like my carb just fine
DITTO!
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LOL, for older bikes to. I mean who would waste money on old technology, oh wait, the yz250...oops
Oh no,not the old technology YZ thing again. :o I guess the TM,Gasgas,husky,KTM etc have all the new 2t technology.I hear the difference is...er....um...... ::)
Well, I just read a comparison between the 250sx and the yz250. Apparently the yz handles better while the KTM rapes it. ;D
is this review online somewhere?
with this talk about DI i looked at Orbitals page and in particular the dyno of the injected 450 2 stroke compared to the 450 4 stroke. the 2 stroke blows the 4 stroke out of the water and apparently that was a very under engineered 2 stroke. so that got me wondering whether a DI 2 stroke that is engineered to really perform could produce enough power and torque to give a 450 4 stroke a run for its money? if it could it makes the ama ruling not of capacities not so bad
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In theory a DI 2T would inject into the combustion chamber after the exhaust port is closed resulting in less "hit" and a whole lot more low speed torque.If you look at the numbers DI snowmobiles and outboards are producing I'd take a DI 2T dirt bike any day. ;D
Why would that produce more torque? DI isn't good for part throttle or off pipe applications (which makes it easy to rig up on sleds and eggbeaters) then there is the issue of big end and crank bearing lubrication. Sleds run 'dry' bottom ends with sophisticated oil injection which could never be packaged on a dirt bike.
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Carbed 250 2Ts are already producing torque and horsepower figures close to 450 4T$ it's just that the 4T$ are smoother.With DI a 250 2T would match or exceed a 4T and be nearly as smooth.
The achilles heal of the Schnurle loop 2T is that during the scavenging /exhaust cycle part of the fuel/air intake charge is lost out the exhaust port (hence expansion chambers). Direct injection would introduce the fuel mixture into the combustion chamber after the exhaust port is closed (at low rpm anyway) resulting, in my mind,more low speed torque.You could well be right about the present technological limitations but problems were made to be overcome. ;D
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Sorry but im not too too familiar with DI but i was wondering if a 2 stroke was equipped with DI can you keep the "hit" in the torque curve or does it have to be smooth like a 4 stroke?
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LOL, for older bikes to. I mean who would waste money on old technology, oh wait, the yz250...oops
Oh no,not the old technology YZ thing again. :o I guess the TM,Gasgas,husky,KTM etc have all the new 2t technology.I hear the difference is...er....um...... ::)
Well, I just read a comparison between the 250sx and the yz250. Apparently the yz handles better while the KTM rapes it. ;D
The exact same thing was true in 03.No technology difference,just different set up-as in all comparisons over the years.A riding buddies 03 250SX was virtually unrideable to a spode like me-and him as well.I could run virtual circles around him and such wasn't typically the case.It had too much,too fast,too hard.In later years they toned it down.It was certainly fun,but not very effective.
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Carbed 250 2Ts are already producing torque and horsepower figures close to 450 4T$ it's just that the 4T$ are smoother.With DI a 250 2T would match or exceed a 4T and be nearly as smooth.
The achilles heal of the Schnurle loop 2T is that during the scavenging /exhaust cycle part of the fuel/air intake charge is lost out the exhaust port (hence expansion chambers). Direct injection would introduce the fuel mixture into the combustion chamber after the exhaust port is closed (at low rpm anyway) resulting, in my mind,more low speed torque.You could well be right about the present technological limitations but problems were made to be overcome. ;D
Pipe still does the work, would make a difference in emmissions for sure, but well designed Aprilia GP cylinders lose virtualy NO intake charge out the exhaust duct.
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In theory a DI 2T would inject into the combustion chamber after the exhaust port is closed resulting in less "hit" and a whole lot more low speed torque.If you look at the numbers DI snowmobiles and outboards are producing I'd take a DI 2T dirt bike any day. ;D
Why would that produce more torque? DI isn't good for part throttle or off pipe applications (which makes it easy to rig up on sleds and eggbeaters) then there is the issue of big end and crank bearing lubrication. Sleds run 'dry' bottom ends with sophisticated oil injection which could never be packaged on a dirt bike.
exactly. If it aint broke don't try and fix it
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Sorry to have to disagree with you on the DFI thing. Yes it is more complicated but the guys from the 60's and 70's said the same thing about reed and power valves and long suspension. (Side note: In 1975, Husqvarna produced the WR range on the MK frame because Enduro riders were afraid the taller bikes would not work as well in the woods - See? Change is a good thing).
The reason for DFI isn't to increase torque, power or cost. The reason is to reduce exhaust emissions and meeting current and future green house gas emission requirements. DFI on a 2T will do that. The increase in performance is just a bonus on the side .
Look, regardless where you stand on the whole environmental issue, the laws are going to get tougher, not easier. You will not get someone in the White House that will just 'see the light' and make it all go away. The only hope for current 2T's is for the next version to run CLEANER than competing engines AND for ALL new engines to run cleaner. That way, all governments (not just the USA) will not legislate them out of existence.
Right now, your Y2K technology 2T is legal on closed courses just about everywhere, but there could come a time that you will not be allowed to fire up your 1981 Maico, 1972 Husqvarna, or 1969 Bultaco. Laws will also target your boat motors, weed whackers and other lawn and garden equipment (where I live now, you can't buy a new 2T boat motor). Hopefully they won't make a law prohibiting 2-stroke technology and just make the law limiting emissions. It will happen in Kalifornia first, but you can bet it will happen. And where goes Kalifornia...
DFI (or some other computer controlled technology) is our way to the future. Embrace it and don't be afraid of change.
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The story of Battle Star Galactica or The Terminator comes to mind when I think of computer controlled technology.
And as far a emissions are concerned, IMO the only real smog problems are in major metropolitan areas that are geographically located in valleys, and other areas where the wind is incapable of blowing away the polution. I don't think I ever rode my 2t dirtbike on a freeway in LA so who gives a rats ass. I think these areas should police thier own smog problems and leave the rest of the country alone. I don't think it's fair that Billy Joe in Montana should have to have his 77 chevy truck smog checked or not be allowed to to ride his 2t dirtbike in a practically unpopulated area because 5,000,000 people in LA and New York won't ride a bike, take a bus, or walk a couple of miles to work.
The big poluters are the electrical companies that still burn coal to produce electricity, what is this 1820?
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In theory a DI 2T would inject into the combustion chamber after the exhaust port is closed resulting in less "hit" and a whole lot more low speed torque.If you look at the numbers DI snowmobiles and outboards are producing I'd take a DI 2T dirt bike any day. ;D
Why would that produce more torque? DI isn't good for part throttle or off pipe applications (which makes it easy to rig up on sleds and eggbeaters) then there is the issue of big end and crank bearing lubrication. Sleds run 'dry' bottom ends with sophisticated oil injection which could never be packaged on a dirt bike.
Care to elaborate on the 'not good for part throttle or off pipe' piece?
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Myck (et al),
I fully agree with you. Unfortunately 'the powers the be' (or the 'powers the will ever be') do not. They could legislate us right out of existance and will if some have their way. What we need to do is evolve; change with the times and keep what is good and golden in our sport while trimming and minimizing what is bad.
Look, my father made his fame in carb'd race cars, tuning them better than his peers. However, he didn't just up and quit because the 911 went fuel injected. He had to adapt to the new technology to keep up with the competition. We need to do the same.
I'm not so sure that I'd want to be in the middle of Baja during the 1000 with fuel injection problems on a new bike. I would feel much more comfortable taking apart the old carb and cleaning it out there. But the majority of us are not in the Baja 1000, Dakar, or other super remote location. We show up at our local MX track and shower at home and sleep in our beds. Having a new technology like FI (or DFI) would only be a problem for a short while. Systems would become more and more robust until everyone would look back on the carb as an evil of the past - and good riddance!
Top MX'ers today already plug into a computer. I don't see why that is a problem. Of course, I am a computer guy...
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Alright i was just on facebook and insidermx posted a link to the 2012 honda models and not a single 2 stroke
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That's nothing new.
Even manufacturers that DO make 2 strokes, don't always advertise them.
It's the well known marketing scandal...
As for DI:
KTM has clearly said that they will not be switching their carbs for DI anytime soon.
For now, and the coming 3 to 5 years, KTM's 2 stroke range can easily pass all current (and upcoming) emission rules with their current carburetted 2T engines...
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KTM has clearly said that they will not be switching their carbs for DI anytime soon.
For now, and the coming 3 to 5 years, KTM's 2 stroke range can easily pass all current (and upcoming) emission rules with their current carburetted 2T engines...
That is my point, 4t$ produce more pollutants than a 20 yo 2t. They argue that because you can see it it is worse. B/S!!!
The smoke from a 2 stroke is mainly moisture from unburnt oil, mostly oil made from BEANS!!!! and disappears as the bike warms up, the weight of it is too heavy to be carried up into the atmosphere. So it falls to the ground.
I am not afraid of technology, I am afraid of the escalating costs of everything that technology brings with it, with out increasing what the majority of the world is paid in wages for producing, selling, and using it.
Everytime I turn around, the cost has gone up 15% on something else but the minimum wage is still $7.25. wtf.
I don't make minimum wage, but my point is that it is what most other jobs are based upon. So $11.00 an hour is "decent" paying job because a fry cook starts at $7.25? My wife went to school for 2 years to work a job that started her at $11 an hour. And she only works 4 days a week. She could make the same money working full time at McDonalds and I wouldn't have had to pay $25,000 for her degree.
She has to work 1 day just to put gas in her car to get to work the other 3
oh shit I bettert stop before I get on the Welfare rant highway. LMAO
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(where I live now, you can't buy a new 2T boat motor).
I hope you mean carb 2T outboards. If anyone has told you other wise they are full of shit.
Both Mercury & Evinrude produce DI 2T motors that pass all emmission laws.
I know of a Honda dealer who tells people that 2 strokes are going to be banned on our lakes and he knows it is an out and out lie. >:(
Hopefully they won't make a law prohibiting 2-stroke technology and just make the law limiting emissions. It will happen in Kalifornia first, but you can bet it will happen. And where goes Kalifornia...
That is a popular misconception started by the greens & 4 stroke manufactors.
The legislations enacted by the US Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) as well as EU Recreation Craft Directive REGULATE EMISSIONS AND NOT TECHNOLIGIES.
In other words you can build anything you like as long as it passes the emission standards.
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I hope you mean carb 2T outboards.
"Where I live" (no longer in the US), you can't BUY 2t (carb or not) boat engine. They are not available. Whether that is due to importation laws, emissions laws, or lack of a dealer network, I don't know. I do know that Evenrude has stated they will only produce 2t motors from now on...but I can't get an Evenrude. >:(
That is a popular misconception started by the greens & 4 stroke manufactures.
I agree that CURRENT laws in the US set emission standards. What I said was "Hopefully they won't make a law prohibiting 2-stroke technology and just make the law limiting emissions." Lawmakers are not engineers and wouldn't know a 2t from a toothbrush. And I also referred to ALL lawmakers, not just those enlightened souls in charge in the US. Other countries have suggested out and out BANS on all new 2-stroke engines AND the oil used for premix for older engines.
4t$ produce more pollutants than a 20 yo 2t.
Uh, yes and no. A 2t is cleaner in some areas, worse in others. Although the NOx readings are significantly lower, Particulate Matter emissions is much-much higher and is very important in large cities like LA, London, Bombay and Bangkok. London has gone so far as to ban all diesels produced before 1996 in the inner ring of the city due to the Particulate Matter emissions. More importantly however is the HC reading where a 2t is 4 times worse than a 4$ and 10 times worse than a modern SUV!
However, DFI solves all these problems and has side benefits of more power and better (read easier) power delivery.
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Care to elaborate on the 'not good for part throttle or off pipe' piece?
Sure off pipe refers to when the engine is not in phase or 'powerband' , part throttle is well part throttle both of which are intertwined on a 2T engine because the pipe is not working, when the pipe doesn't work nor does everything else in the engine.
Have a think about this. There was a time when the horse not horsepower was everyday transport for the masses. Today there are still horses they are not used for mass transport but for recreation and horse racing is a multi billion dollar industry. If alternatives to the IC engine(2T or 4T) that's how I would like to see it end up.
The use of Bio fuels (e85 in particular) can stop harmfull/particulate emissions buy 80-90% in a 2T engine. I have yet to hear of any country banning 2T or pre-mix.
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Hold up there buddy ;D Ethanol actually increases carbon foot print along with any bio fuel. It burns twice as fast as Plankton Crude Oil, and actually has no benefit what so ever other than raise produce prices, oh wait that isn't a benefit. E85, global warming, being green is a joke. ;)
Whats hilarious is people stating that 2 stroke are greater polluters than 4ts, when 2ts only burn so much of the gas and then it gets expelled out the silencer. 4t are naturally lean, and end burning gas at higher temps producing more carbon. By making the 2t more efficient with EFI or DI you get a cleaner burn, and with less fuel being used at the same time, so you get more power, and better gas mileage. Its a win win scenario. ;D If most of you would read some of the EFI sled reviews you would know this.
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You mean all this time I have spent processing burger juice for my Mercedes Diesel has been a waste of time? I thought that farmers grow canola,it is refined into cooking oil for the fast food industry,I recycle it into fuel and the carbon emitted is reabsorbed by new canola plants resulting in a negligible carbon footprint.
Due to less internal engine friction,DI 2T BRP snowmoblies are actually getting better fuel economy then Yamaha 4T sleds of a comparable output.
I suspect a DI 2T dirt bike could be quite an exciting ride,at low rpm you would have a lot more boost due to less scavenging losses and as engine speed rises and the DI has trouble keeping up the expansion chamber would still come into play with that 2T blast. ;D
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Hold up there buddy ;D Ethanol actually increases carbon foot print along with any bio fuel. It burns twice as fast as Plankton Crude Oil, and actually has no benefit what so ever other than raise produce prices, oh wait that isn't a benefit. E85, global warming, being green is a joke. ;)
Whats hilarious is people stating that 2 stroke are greater polluters than 4ts, when 2ts only burn so much of the gas and then it gets expelled out the silencer. 4t are naturally lean, and end burning gas at higher temps producing more carbon. By making the 2t more efficient with EFI or DI you get a cleaner burn, and with less fuel being used at the same time, so you get more power, and better gas mileage. Its a win win scenario. ;D If most of you would read some of the EFI sled reviews you would know this.
Everyone needs to slow down a little. Everyone is posting something that isn't correct. Go do some research on bio butanol and get back to us about buring twice as fast etc. Second, E85 while burns faster may have less BTU, it actually does have benefits. It is well known as the poor mans race fuel in the turbo industry. It is less prone to detonation, compared to on the street fuel. It is cheaper than buying race fuel. Yes, at a cost. I'm not advocating E85.. Just saying there is benefits in certain things. It burns faster, but at that faster rate, it gives more hp. My CR144 will be run on it. Testing with that, may lead me to go on all bikes. Because $ VP fuel is getting expensive. Anyone who doesn't believe in detonation on pump gas I can show a piston too.
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LOL, its alcohol, and its cheap for now :-X.
LOL, the only time I had a detonation problem was when I ran 92 octane Premium with 10% ethanol, here is a pic:
(http://i56.tinypic.com/a0kljc.jpg)
This happened 5 minutes after it went into the bike.
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LOL, its alcohol, and its cheap for now :-X.
LOL, the only time I had a detonation problem was when I ran 92 octane Premium with 10% ethanol, here is a pic:
(http://i56.tinypic.com/a0kljc.jpg)
This happened 5 minutes after it went into the bike.
You can't blame the ethanol. :P Maybe the fact that it is used to raise octane, but not the ethanol in itself. Because it has a higher octane level. Our fuel has all kinds of additives. Did you know xylene is in your fuel to buy? It's crap fuel period. I make my own fuels at times, but it ends up being a pain, getting accurate numbers.
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You can't blame the ethanol. :P Maybe the fact that it is used to raise octane, but not the ethanol in itself. Because it has a higher octane level. Our fuel has all kinds of additives. Did you know xylene is in your fuel to buy? It's crap fuel period. I make my own fuels at times, but it ends up being a pain, getting accurate numbers.
Which is one of the reasons I run Avgas, the fuel is more consistent, and correct me if I'm wrong but I thought alcohol and oil didn't mix.
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I run 92 octane ethanol free premium, and it eats plastic cups.. :-X
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I run 92 octane ethanol free premium, it eats plastic cups.. :-X
100LL Avgas won't harm a styrofoam cup but if you mix any auto fuel with it the cup gets eaten up
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weird.
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You can't blame the ethanol. :P Maybe the fact that it is used to raise octane, but not the ethanol in itself. Because it has a higher octane level. Our fuel has all kinds of additives. Did you know xylene is in your fuel to buy? It's crap fuel period. I make my own fuels at times, but it ends up being a pain, getting accurate numbers.
Which is one of the reasons I run Avgas, the fuel is more consistent, and correct me if I'm wrong but I thought alcohol and oil didn't mix.
Now i don't claim to be an expert on fuel but i'm of the understanding av gas isn't as volatile due to use at altitude, and that negates it's performance potential. I've been recommended to mix it 50/50 with 98 pump gas and have done with good results.
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I can't claim to know much about blending gas but my experience has shown me that:
When I ran race gas (up to 2001), I'd buy a 55 gallon barrel of Sunoco 116 leaded race gas and it worked out to $3.50 a gallon more or less (ah, the good ol' days). We tried mixing it with pump gas but we could not get consistent gas from the stations to get a consistent blend so we ran it straight. That had the added benefit that I wouldn't be throwing gas away (or using it in my cars) we it went bad at the end of the month.
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Care to elaborate on the 'not good for part throttle or off pipe' piece?
Sure off pipe refers to when the engine is not in phase or 'powerband' , part throttle is well part throttle both of which are intertwined on a 2T engine because the pipe is not working, when the pipe doesn't work nor does everything else in the engine.
Sorry, I guess I was "a bit" vague in my question. I was more looking for the reason why you think that DI is unsuitable for such operating conditions. (links?)
I would think quite the opposite, as long as the computer knows what amount of fuel to inject for every given operating condition. -That's probably the challenge...
Have a think about this. There was a time when the horse not horsepower was everyday transport for the masses. Today there are still horses they are not used for mass transport but for recreation and horse racing is a multi billion dollar industry. If alternatives to the IC engine(2T or 4T) that's how I would like to see it end up.
I don't care for that kind of horse, racing or not ;)
The use of Bio fuels (e85 in particular) can stop harmfull/particulate emissions buy 80-90% in a 2T engine. I have yet to hear of any country banning 2T or pre-mix.
This might be of interest, on the topic of DI two-strokes:
http://www.orbitalcorp.com.au/tp/pdf/2007-32-0001.pdf (http://www.orbitalcorp.com.au/tp/pdf/2007-32-0001.pdf)
"Keywords: Performance Engine, 2â??stroke, 4-stroke, Direct Injection, Recreational Vehicle Application"
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Computer might know lots of things but try getting it to talk to the pipe. The pipe governs everything.There is a few things I cannot say much about at this stage, hopefully IF it is taken up by manufacturers you will see what I mean.
I Australia we get very good fuel from the pump I have a unspecified blend of 98 RON and e85 fuel each and every time it's dynoed we see a gain like this.Avgas gan make some good HP (it is made not to detonate) but you can make more with unleaded as it burns much faster.Avgas and ULP require completely different set ups so mixing 50/50 seems like a half pregnant idea to me.
(http://i155.photobucket.com/albums/s297/Lozza85_2007/fuel.jpg)
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Computer might know lots of things but try getting it to talk to the pipe. The pipe governs everything.
I don't think it is that hard. The computer can read sensors in the pipe and engine to "adjust" fuel/air mixture and exhaust valve size.
Pipe design is easily done today with a computer program ($14 online!).
Now down get me wrong, I'm sure the knowledge of an expert 2-stroke pipe builder/turner is irreplaceable, but the basics can be done on computer and probably on the fly (fresh ding on your pipe today? - tweak tweak!)
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Computer might know lots of things but try getting it to talk to the pipe. The pipe governs everything.
I don't think it is that hard. The computer can read sensors in the pipe and engine to "adjust" fuel/air mixture and exhaust valve size.
Pipe design is easily done today with a computer program ($14 online!).
Now down get me wrong, I'm sure the knowledge of an expert 2-stroke pipe builder/turner is irreplaceable, but the basics can be done on computer and probably on the fly (fresh ding on your pipe today? - tweak tweak!)
putting a sensor in a 2stroke exhaust pipe has lots of problems i'd think.
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All this talk of DI,pipe sensors,hit etc strikes me as kind of funny.This is all old hat on snowmobiles.I can't imagine anyone having an issue with DI.It may well be the savior of the 2t engine as we know it.Besides,anyone who has ever ridden a DI or SDI set up(hand in the air here)can attest that there are zero performance issues.They flat out fly-plain and simple-with enough "hit" to put you over backwards on your head.Better performance,economy and emissions may be an obvious downside. ;D
On the other hand,I imagine many complained when "reliable" drum brakes were replaced with new-fangled,"hopelessly problematic" discs. ;)
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This is exactly the same discusion I remember having with other mechanics in the mid 80's when EFI came out on cars.
How did that go.? ;)
putting a sensor in a 2stroke exhaust pipe has lots of problems i'd think.
The old Ficht system had an exhaust pressure sensor. And yes they used to block occasionally. 200-300 Hours.
I think it was caused by the oil as I have tried it in my bike and it runs very sooty.
Easily fixed with better oil.
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2T Institute.
You seem to know abit about 2 strokes. ;)
Do you know if the orbital 450DI dyno chart we have all seen, If they were running a standard expansion chamber design or if they tried something different.?
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For the 100 millionth time.............
Sleds have a CVT and that allows a narrow operating rpm and on/off throttle applicatons, which like a outboards lend themselves to EFI.
ECU's have trouble coping with the different demands on fueling between on and off pipe.
Free or cheap pipe calculators are worth every cent you pay for them ::) There is a lot more to making a good pipe than punching in a few numbers into a program.
Trouble is getting enough power in the ECU to cope with the rapid change in dynamics that the pipe causes. That is expensive and cause packaging contraints. Which on a sled or a Outboard are not an issue.
Right now nobody wants to spend the $$$ to make the ECU.
EDIT
I haven't seen any dyno charts yet
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In theory,and I'm thinking aloud here,if the ECU could keep up with the increasing RPM of a 2T and ALWAYS inject fuel into the combustion chamber after the exhaust port closed at the correct time before TDC ,an expansion chamber would not be needed?The reality is that due to time constraints the injection timing has to be advanced relative to increasing RPM to the point where the exhaust port is open at a certain engine speed.Hence, an expansion chamber is still needed and the ECU,given the present level of technology,has great difficulty making this transition.With this in mind,wouldn't it be easier to adapt DI to a relatively low RPM 500cc motocrosser then a screaming 125? ::)
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For the 100 millionth time.............
Sleds have a CVT and that allows a narrow operating rpm and on/off throttle applicatons, which like a outboards lend themselves to EFI.
ECU's have trouble coping with the different demands on fueling between on and off pipe.
Free or cheap pipe calculators are worth every cent you pay for them ::) There is a lot more to making a good pipe than punching in a few numbers into a program.
Trouble is getting enough power in the ECU to cope with the rapid change in dynamics that the pipe causes. That is expensive and cause packaging contraints. Which on a sled or a Outboard are not an issue.
Right now nobody wants to spend the $$$ to make the ECU.
EDIT
I haven't seen any dyno charts yet
Interestingly,I've never realized that a clutch system had any bearing whatsoever on the fuel delivery system of an engine.
A snowmobile clutch does allow the power to be delivered over a steady,narrow,optimal band but this has nothing to do with the design or engineering of the engine.Snow mo's still use expansion chambers as well.Technically speaking,if you're not entirely spastic with a motorcycle,you can accomplish a reasonable facsimile of the sno mo set up with your throttle hand,clutch hand and left foot.A DI system doesn't only work at one exact point,it works better everywhere.The "hit" you long for isn't as a result of superior,archaic engineering but rather a result of that point where everything is working optimally.DI doesn't lose anything but it does vastly broaden this range and would therefore minimize the perception of a "hit"
As for the "ECU's have trouble coping" thing,all I can say is ;D
It's also not that hard or expensive to build one-and a small one at that.Many modern day cars ECU's are no bigger than a paperback but thinner.Do you suppose they have to make less calculations than a 2t single cylinder running a DI system would?
DI is the present and future,it's already proven and vastly superior-for the 100 millionth and one time.I just hope someone sticks it on a bike. 8)
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;D
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TMKIWI, you can read up about the Orbital concept in the link I posted earlier: http://www.orbitalcorp.com.au/tp/pdf/2007-32-0001.pdf (http://www.orbitalcorp.com.au/tp/pdf/2007-32-0001.pdf)
2T Institute, while I agree that the two-stroke puts a tremendous load on the ECU, and with your view on cheap pipe calculators, I strongly disagree with the statement that sleds are an on/off application. CVT and relatively constant RPM, yes, but limited to on/off operation, no way! -Imagine running a 160hp sled in on/off operation on a tight trail... On to the outboard engine, it needs to be able to run at different loads over a wide range of rpm, although the normal operating condition would be more or less constant throttle.
SachsGS, the pipe is still needed to achieve high specific power. DI addresses only the "simple" part, getting the right amount of fuel into the combustion chamber. You still need to squeeze in as much air as possible, and that's where the pipe come into play.
The amount of computing needed increases with increasing RPM, and the available time window for fuel injection and evaporation decreases with increasing RPM. -So yes, it should be easier to implement on a large low RPM engine. The Etec 800 reach max power close to 8000rpm thoug..
(http://i55.photobucket.com/albums/g140/strubmotorsports/ETEC.jpg)
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This new fangled DI business seems all a bit over complicated, ive never like fuel injection and never want a vehicle with it, just give me a carb and a cable going to my right hand and ill be happy!
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This thread and threads like these are actually why I come to TSM. The exchange of ideas with like minded people.
@ George: Although I agree with you and probably everyone else here visiting TSM pretty much agrees with you, many of us also believe that if 2t engines and motorcycles in particular don't evolve and become cleaner and more efficient, they will be legislated out of existence.
@ 2TInstitute: Yes, you are correct about the $14 pipe designer software. However, I was hoping you would read into my comment though that 'if a $14 pipe program is available - and works, don't you think a well designed FI system and ECU could adjust for it and work well too?'. I really don't (and didn't at the time) mean to offend you. That is why I put the comment "...I'm sure the knowledge of an expert 2-stroke pipe builder/turner is irreplaceable,...". Pipe builders are 'GODS' had have a magic like that of a fine luthier. I have the utmost respect for them and I am confident that there will still be a place for performance improvements in the pipe of a DFI production bike. If for nothing else than the pipe will still be a major part of the system that a rider can 'tune' to his (or her) own needs on a given track or terrain type.
@ teriks: Thanks for the sled information. I have wondered about that for awhile but not bothered to look it up. I really do love this stuff!
@ TMKIWI: Yes. I said the same thing. Although I drug my feet with mechanical FI, not trusting Bosch electronics, I always knew FI was the way forward. However, even though we adapted it on the boats quickly, on our desert buggies, we still used the carbs for the longest time.
@ Ford832: As to your thoughts about the clutch, the 'hit' of a 2t is MOSTLY a product of the flywheel; less hit - heavier flywheel, and vice versa. Being that 2t engines are small, you have wasted HP in having to keep that weight spinning. To paraphrase, "in the battle for performance, he who can ride with the smallest clutch weight (most HP), wins." Compare 2 Yamaha products, the DT and YZ. They are both 125's but the YZ makes a ton more HP and even 'detuned', still has a significant hit. Yes a lot of that has to do with things like porting, exhaust, piston and head shape but the DT was designed for the street and has a huge flywheel and rides almost 'electric' like. I don't have the experience with the sleds but I believe your experience is 100% valid, and that was the main point of my original post. FI (of some kind) is the way of the future, we should be embracing it and encouraging manufacturers to supply it.
I am of the belief, and correct me if I am wrong, that the problems with FI are 3 fold; The ECU, Cost, and Perception.
-First, that the ECU is fragile and susceptible to exposure to heat, dust, water, and vibration. Packaging one to survive on an off-road motorcycle and making it small enough might be an issue. Powering it (without adding the weight of a battery and charging system) might also be an issue. Of course if the trend set by Husaberg and KTM continues of putting electric starters on 2t's, problem solved!
-Second, will the product and development costs be recouped by a company who produces it or will it price itself out of reach of the consumer?
-And third, will the consumers embrace the new technology and buy it or will they clamp down to the old ways like I did with drum brakes. (Yes, I was one of those who didn't trust the fragile disks and was reluctant to accept change). That might not be an issue if carb'd 2t's are legislated away.
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In theory,and I'm thinking aloud here,if the ECU could keep up with the increasing RPM of a 2T and ALWAYS inject fuel into the combustion chamber after the exhaust port closed at the correct time before TDC ,an expansion chamber would not be needed?The reality is that due to time constraints the injection timing has to be advanced relative to increasing RPM to the point where the exhaust port is open at a certain engine speed.Hence, an expansion chamber is still needed and the ECU,given the present level of technology,has great difficulty making this transition.With this in mind,wouldn't it be easier to adapt DI to a relatively low RPM 500cc motocrosser then a screaming 125? ::)
That is correct there is a retro fit kit for 125 commuter bikes(for use in developing countries) that have an injector plumbed into the head, I know think is out there somewhere, the carb was removed and the reeds just sucked air, but yes the engine was not dependant on the chamber.
A CVT is a constant velocity transmission not the clutch, the CVT (as with the DI Aprilia 50 scooter) has no gearbox ratio, but infinitely variable, so the engine is tuned to a very narrow band, with out 'gaps' between the gears they don't fall out of band. So you just hold a relatively constant throttle when moving and the CVT does the work. A bit different story to going round a snotty , rutted off camber corner or up that snotty hill, where the rider will be just 'surfing' the point of the engine going into band, feeling the optimum point to open the throttle.(That's what MotoGP riders do with traction control)
Well if ECU's don't have trouble making all the calculations , you should have no trouble making one work on a 2T then should you?
Time is the killer or lack there of, so we go to simple maths, most sleds have the ex port open at 80deg ATDC, piston rises and falls and rises to TDC 133 times a second, or 0.0075 seconds to go from TDC to TDC, the time from ex port close to ex port open is 0.00375seconds(that's for 90 deg to make my calculations easier), assuming that ignition is at 14 deg BTDC, which is 0.00058 seconds BTDC we have to inject before then, that leaves a period of 0.00317 seconds to get all the calculatons right for that cycle. I know, I know that the piston is decelerating as it approaches TDC but for illustration purposes you get the idea, which again is fine on pipe but off pipe the ECU cannot distinguish the fueling needs because of the unreliable inputs from the pipe. A carb does this with ease as it is an intellignet device, the ECU has to be told what to do. What normaly happens is the ECU get tricked into thinking the engine is lean (off pipe).
I install programmable ignitions every week and there are robust as, there is no 'brick wall in the head' about the use of technology, BUT you have to accept that when groups of talented engineers like HRC and at Cagiva attempt EFI engines and GP riders call them 'unridable pieces of shit' (sic Carl Fogarty) they probably are. If the nut was easy to crack it would have been cracked many moons ago.
Don't forget it took a few attempts to get discs (on road bikes) anywhere near the performance of good 4LS drum brakes, by the time discs appeared on dirt bikes they were pretty sorted(first few aside)
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That is correct there is a retro fit kit for 125 commuter bikes(for use in developing countries) that have an injector plumbed into the head, I know think is out there somewhere, the carb was removed and the reeds just sucked air, but yes the engine was not dependant on the chamber.
Envirofit
http://www.youtube.com/watch?v=EjBcxyKkpEE
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I forget,so the expansion chamber in a 2T functions as well like a megaphone exhaust on a 4T in that it helps "draw" the spent fuel/air charge out of the combustion chamber (in addition to providing a return resonant wave to block the exhaust port)?
Would it also be true to say that most of the pollution in a 2T occurs in an "Off the pipe" situation and that small utilitarian 2T applications that typically don't have tuned exhaust (ex.:weedwackers and chainsaws) would be the worst offenders?It would seem to me that small,all position and essentially single speed applications,like a weedwacker once again,would seem to benefit the most from DI.
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I don,t like the DI system, a pal of mine worked with the KTM mx team, if you change the pipe you have to reprogram the computer, and that,s a on a 4-st. I had numerous break downs in the last 2 weeks, the 20 inch deep potholes and rough roads, tear a truck up. Some of the stuff is computer related and sensors, wireing to sensers breaking, I bypassed a couple sensers just to get the truck to move out of a dangerous break down spot. IMO sensers do not belong on a mx bike. A mx bike doesn,t get half the beating a truck gets, but still, Honda doesn,t need DI to sell the bike. Who has over 200.00 in gas to go riding anyway.
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I forget,so the expansion chamber in a 2T functions as well like a megaphone exhaust on a 4T in that it helps "draw" the spent fuel/air charge out of the combustion chamber (in addition to providing a return resonant wave to block the exhaust port)?
Yes, if we keep it simple.
Would it also be true to say that most of the pollution in a 2T occurs in an "Off the pipe" situation and that small utilitarian 2T applications that typically don't have tuned exhaust (ex.:weedwackers and chainsaws) would be the worst offenders?It would seem to me that small,all position and essentially single speed applications,like a weedwacker once again,would seem to benefit the most from DI.
Not necessarily so, but the real killer for HC pollution is four stroking operation, -IE misfiring every other stroke.
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2T institute.CVT's on snowmobiles are commonly called the primary and secondary clutch and are both the clutch and transmission but if nit picking the terminology trips your trigger,that's cool.
A DI set up is hardly a standard engine with an injector plumbed in to it.If time available to inject the fuel is your issue you need to realize the BRP DI injector operates at 500psi.Even a car at a 600 RPM idle with an old style low pressure injector has an pulse width of about 2.5 milliseconds.
As we all know,on a standard 2t,after the fuel has traveled the transfers and the backpressure wave has forced some of the unburnt fuel back into the cylinder and the piston has closed the exhaust port,the charge still has to be compressed before the plug fires.This takes time,and time enough for an injector to fire.The backpressure wave is virtually irrelevant in a DI system as pertaining to lost fuel charge because there is none so the exhaust port window can be altered to allow more time if that was ever an issue.
It's not a matter of how someone could solve all your perceived issues,BRP has already done it on a 9000 RPM snowmobile engine.How much power is your bike still making at this point?The injector has time to fire,the ECU makes the calculations even with the "unreliable inputs from the pipe"(whatever that means).
I like Foggy's quote though.When was that?10 yrs ago?15?Things have come a long way in the last few years.
The "nut" was mostly cracked with BRP's SDI system and is fully now.Naturally,you're right,I couldn't build one.I'm just a dumb mechanic,not an computer programmer or a mechanical engineer.I'm also not vain enough to assume that just because I'm too dumb to do something that no one else could do it either.Not everyone shares this perspective however.
I've never heard a carb called an intelligent device before.I was unfortunate enough to have to work through the carb era in auto and EFI systems have been a godsend.Carbs worked fine when that was all that was available but they were outdated many years ago-in every possible way.Maybe some carbs I've yet to see are "intelligent" enough to compensate for temperature,pressure,crank pos,intake temp,exhaust etc,etc,etc like all EFI systems.I guess I just missed that one.
On the other hand,if you want to really know how crappy the new sno mo/outboard systems are,ask TMKIWI.If I remember correctly,he works on them.
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VintageBluSmoke.The "hit" isn't a product of flywheel weight but rather engine design.Granted,the exact same engine with a heavier flywheel will have less hit than the same with a lighter flywheel but this is due to the fact that the heavier flywheeled engine has more rotational mass hanging off the end of the crank and therefore more "load" on the engine.It takes more to get this spinning which softens the perception of the hit.Interestingly,a bike with a strong bottom,mid and top has less hit that a bike with a poor bottom and strong mid.
This often makes slower bike seem faster due to the fact it takes off when it actually gets in to the power.
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I like this thread. ;D
I under stand what you are saying 2T about injection time. It has aways been the issue. The problem with your comments about Foggy is that was a long time ago.
When Honda and co were working on injection systems the problem was aways EMM speed or lack there of.
Also in the late 90's as you know 500GP's were going to be replaced with 4 strokes so there was not much point in continuing with developement. And as you have said trying to make it work on a 13000rpm GP bike was never going to be easy back then.
The same issues were found on the early Fichts which had no end of problems mostly caused by EMM/ECU's.The early Optimax/Orbital Mercury's had issues with pistons melting :o and other issues. These have all been overcome.
I have been in the outboard industry 10 years and the early days were nightmares with all sorts of weird and wonderfull breakdowns. (Thats why I am half bald) :D
BUT all the problems were solved and the main reason is better electronics.
Back to injection time: You dont actually need to inject the fuel AFTER the exhaust port has closed. If the porting and combustion chamber design is correct the incomming air "swirl" will scavange the motor as it does now AND keep the fuel away from the exhaust port when it is still open. Combined with the exhaust return pressure wave the fuel can be injected before the exhaust port closes and no fuel will escape. This is what BRP have done.
Here are my thought on making it work on a dirt bike. The engine needs to be 300 to 500cc so you have a 8000rpm ceiling.
To help with the exhaust pulse issue remove the power valve from the engine. In it's place put a exhaust valve/flap in the pipe which will vary the exhaust pulse lenght further away from the comustion chamber and leave a nice large port. Operated by a simple servo motor.
Some model ETEC's have this and when driving you can feel a "Hit" as the valve opens.This should give you an engine with mountains of torque over a broad range.
It might not be a 70Hp CR500 killer but will still produce more power and torque then a 4 stroke. Baby steps are needed.
Not saying it will be easy but I certainally don 't think it is impossable.
Thats my thought on the matter.Lets keep it going ;D
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Ford,I wouldn't worry about being a "Dumb mechanic",most mechanical engineers are very good mathematically but lack mechanical intuition,the odd guy who has both skill sets is the one most companies are after.At one high tech company I worked for a "Greasy wrench" out of a garage in northern Alberta really did change the course of an industry.His ability to approach a problem from a new and unique perspective allowed the company to leapfrog ahead of the competition.
Werner Von Braun,the guy who put the Americans on the moon,not only had a doctorate in Physics but could also,with his hands,build the rockets.
I like the direction of this thread as well.History often repeats itself and I wouldn't be surprised if a bunch of Honda engineers are secretly tackling the problems of 2T DI. ;D
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@Ford832, I think I said the same thing ;) (re: "Yes a lot of that has to do with things like porting, exhaust, piston and head shape"). But my point was (and maybe my meanderings lead us astray) that the hit is designed into the bike for whatever the use. Since a 2t is so finicky (pipe, timing, flywheel, port shape, weather, terrain etc), a street engine would be designed for very little hit and a wide range of power whereas an MX engine would be produced to provide peak power in a very limited range and those riders that could harness when it was on the pipe were heroes (i.e. Hannah, Jonny O, even Bubba!). Another example was the old Can-Am range. The '75 Can-Am TNT made more power than most any other 250. It was like riding an Open class bike as it had gobs of power all through the range. The MX version however was an Expert Only bike. It made a bit more power but it hit so hard that you had to have a name like Jones, Tripes or Ellis to use it. Ok, that's a bit of an exaggeration but it wasn't your 'average riders' bike. Of course, that had to do with the rotary disc intake as the engines are the same but it serves my analogy.
As for the whole injection timing issue, and I must preface this as I am not a mechanical or electrical engineer, I don't think that is the issue. Maybe 15 years ago, but not today. Nor is processing power in the ECU (although electrical power may be an issue in packaging). F1 engines turn at 19,000 RPM and that is limited by a common ECU (they used to turn more but were limited for longevity by the rules in the cost cutting initiative). Yes, they are multi-cylinder 4$ engines but the principal is the same: Inject x amount of fuel at y time (with y being a product of rpm and other inputs).
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The way i understand it, is the difficulty in getting the necessary information to the computer, how do you monitor the fuel air mixture and prevent a lean situation. I'm thinking the usual sensors wouldn't cut it ie lambda probe or air flow meter. I'm thinking it would be very hard to manage, especially with the more variable throttle input and direct drive nature of dirtbikes.
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The way i understand it, is the difficulty in getting the necessary information to the computer, how do you monitor the fuel air mixture and prevent a lean situation. I'm thinking the usual sensors wouldn't cut it ie lambda probe or air flow meter. I'm thinking it would be very hard to manage, especially with the more variable throttle input and direct drive nature of dirtbikes.
Food for thought: What information does the carb have access to?
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The way i understand it, is the difficulty in getting the necessary information to the computer, how do you monitor the fuel air mixture and prevent a lean situation. I'm thinking the usual sensors wouldn't cut it ie lambda probe or air flow meter. I'm thinking it would be very hard to manage, especially with the more variable throttle input and direct drive nature of dirtbikes.
Food for thought: What information does the carb have access to?
A carb doesnt need information as they are designed and set up to work alongside engines, the engine sucks and the carb gives as much fuel and air as your right wrist is telling it to, but with injection, the engine sucks and the injector tries to know how much fuel and air to squirt at the engine given throttle postition and engine speed etc, so the carb needs no information other than the cable pulling the slide up where as the injector needs to know alot, but you do have a good point.
edited to correct grammer
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Without trying to be pedantic, it's probably correct to say that a well sized, jetted and working carb knows how much fuel to give the engine due to the engines needs and the control of the right hand.
When sized and jetted properly, a carb will provide the correct amount of fuel, however the modern carb with its different jets, matched venturi and everything else is the result of many decades of refinement.
The limitations of fuel injection are ONLY due to current technology and while I am sure the technology is there at the moment, whether it is cost effective to apply it to 2 strike motorbikes (which really aren't going to pay off as a great investment) is another question,
We shouldn't forget that the first carburettors would have been nothing more than a manifold with a hole where fuel dribbled in.
The discussion here should be more about whether there is enough money and desire left in two strokes for anyone to bother financing such an endeavour (as there are obviously some real issues that need to be worked out) I really hope there is, as if not, we will likeley never get to see anywhere the potential that we could have of 2 strokes.
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2T institute.CVT's on snowmobiles are commonly called the primary and secondary clutch and are both the clutch and transmission but if nit picking the terminology trips your trigger,that's cool.
A DI set up is hardly a standard engine with an injector plumbed in to it.If time available to inject the fuel is your issue you need to realize the BRP DI injector operates at 500psi.Even a car at a 600 RPM idle with an old style low pressure injector has an pulse width of about 2.5 milliseconds.
As we all know,on a standard 2t,after the fuel has traveled the transfers and the backpressure wave has forced some of the unburnt fuel back into the cylinder and the piston has closed the exhaust port,the charge still has to be compressed before the plug fires.This takes time,and time enough for an injector to fire.The backpressure wave is virtually irrelevant in a DI system as pertaining to lost fuel charge because there is none so the exhaust port window can be altered to allow more time if that was ever an issue.
It's not a matter of how someone could solve all your perceived issues,BRP has already done it on a 9000 RPM snowmobile engine.How much power is your bike still making at this point?The injector has time to fire,the ECU makes the calculations even with the "unreliable inputs from the pipe"(whatever that means).
I like Foggy's quote though.When was that?10 yrs ago?15?Things have come a long way in the last few years.
The "nut" was mostly cracked with BRP's SDI system and is fully now.Naturally,you're right,I couldn't build one.I'm just a dumb mechanic,not an computer programmer or a mechanical engineer.I'm also not vain enough to assume that just because I'm too dumb to do something that no one else could do it either.Not everyone shares this perspective however.
I've never heard a carb called an intelligent device before.I was unfortunate enough to have to work through the carb era in auto and EFI systems have been a godsend.Carbs worked fine when that was all that was available but they were outdated many years ago-in every possible way.Maybe some carbs I've yet to see are "intelligent" enough to compensate for temperature,pressure,crank pos,intake temp,exhaust etc,etc,etc like all EFI systems.I guess I just missed that one.
On the other hand,if you want to really know how crappy the new sno mo/outboard systems are,ask TMKIWI.If I remember correctly,he works on them.
A 4T engine has 360deg of extra crank rotation, which based on the previous cycles O2 reading 'guess' what the fueling requirement for the next time the valve opens does it not? A 2T engine has at least 2 phases of a cycle happening at any one time 4T's DO NOT. That makes applying electronics very easy.Pipe dynamics are not constant and change with pipe temp, rpm, throttle opening and ignition, that makes reading from pipes unreliable, unless you constantly operate the engine in phase or have a constant pipe temp like an outboard.
A carb is VERY intelligent device as on it's own it can meter fuel over a very wide range of conditions and if you like Lectrons can automaticaly compensate for altitude.Fixed gear kart engines with very simple Tillitson/Walbro carbs with a just a high/low speed tapered needle arrangement can meter fuel effectively from 0-22000 rpm, model plane engines, up to 36,000 rpm.Carbs don't need to compensate for anything other than changes in relative air density, the ignition on a 2T takes care of everything else.
If the ETEC is so good get one saw a cylinder off and stick it in a bike frame can't be to hard can it? In fact I would love to see someone hook up a mega/Microsquirt on a dirt bike,to prove me wrong, but alas nobody seems keen to take up the challenge.
Here is a few uote from a ex-GP engineer (a few people might recognise where it's from)
Fuel pressure is about 3 to 5 bar for indirect injection and about 20 times more for direct injection.
Injectors in the transfer ports do cool the charge - but not very effectively, because there is very little time available for mixing and evaporation of the fuel. If you want to cool the charge, injection in the intake duct is much more effective because the fuel is much longer on its way to the combustion chamber, and meanwhile the charge is intensely stirred by the crankshaft, especially by the conrod. And the big-end bearing needs that fuel.
This is one of the two big problems with direct fuel injection in a racing two-stroke: an Aprilia RSA125 at full throttle on the test bench consumes 1 drop of oil every 30 crankshaft revolutions. That may be enough for lubrication but it certainly is not enough to cool the bearing. Without fuel passing through the crankcase the engine will not live very long...
The second big problem is creating a homogeneous air/fuel-mixture. With direct injection, even when you start injecting at BDC, there is only one half crankshaft revolution available for mixing and evaporation. In the RSA at 13000 rpm that would be 0,002 sec...
With indirect injection or carburation the situation is much, much better. Let us follow a droplet of fuel on its journey through the engine. The journey begins when the droplet exits the carburettor or injector. Four or five crankshaft revolutions later that same droplet appears in the combustion chamber (this is a mean value; some droplets travel quicker, some are slower).
And before you ask: "How do you trace a single droplet?" You label it - with radioactivity. Do not try this at home...
The last experiments with injection on anAprilia two-stroke racer were with the RS500 twin, ridden by Jeremy McWilliams. It had two injectors per cylinder: one in the intake tract and one in the crankcase. Throttle response was ....ehh .... sudden! Fortunately Jeremy was a very brave rider.
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http://bansheehq.com/forums/index.php?showtopic=139722&st=0 (http://bansheehq.com/forums/index.php?showtopic=139722&st=0)
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I am not sure why you keep quoteing about problems from the late 90's 2T as the same issues were present with outboards.
As you have said it is easier with a constant temp exhaust, if the Outboard engineers had problems with an "easier" type engine it is no suprise that GP engines had trouble making it work as well. "With a far more complicated engine."
I have had to work through the issues with the first DI Ficht's from 98' and they were untuneable pieces of shit.
Rough running,failed injectors,fried EMM's,sensors not working etc. There was nothing you could do to fix them properly.
Optimax had melted pistons from too high combustion temps, oiling problems etc.
Fast forward 10 years and we have.................................Engines that work very well.
The next step was getting it to work on sleds that from memory do not have constant temp exhaust's.
You obviously have a wealth of experience in GP's ? but as Sachs mentioned in an earlier post it is amazing what can be acomplished when you put together people from different discipline's. Thinking outside the square.
I agree with Bioflex that the biggest stumbling block is engineers/manufactors making the financial investment to actually build a DI bike.
No one will spend money on something that will not sell.
It will not happen in MX because of the rules. But offroad ?.
Maybe.
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I think you're beating a dead horse 2t institute.It reminds me of arguing all the reasons why an airplane will never fly.
BRP has already done it-the end.As bioflex says,it remains to be seen whether anyone will put it into production.Maybe BRP will do a dirt bike,under the Can Am name.That's certainly feasible if they see a market.
For all you who don't want to see it happen,you better hope it-or something else,does or I expect in a few short years you can kiss your 2t dirt bikes goodbye.
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Ford,I wouldn't worry about being a "Dumb mechanic",most mechanical engineers are very good mathematically but lack mechanical intuition,the odd guy who has both skill sets is the one most companies are after.At one high tech company I worked for a "Greasy wrench" out of a garage in northern Alberta really did change the course of an industry.His ability to approach a problem from a new and unique perspective allowed the company to leapfrog ahead of the competition.
Werner Von Braun,the guy who put the Americans on the moon,not only had a doctorate in Physics but could also,with his hands,build the rockets.
I like the direction of this thread as well.History often repeats itself and I wouldn't be surprised if a bunch of Honda engineers are secretly tackling the problems of 2T DI. ;D
Thanks Sachs but one of my redeeming qualities is that I understand my limitations.On the off chance I forget them,the wife never fails to remind me :( ;D
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Exactly, look at how far 4 stroke engines have gone in the last 30 years, and then look at the 2 stroke engine :-X. They've updated these formula one tech 4 stroke motors every year since they've come out, and now they're producing more power than ever. Its either get EFI/DI 2 strokes going, or slowly watch two strokes die out which is currently happening. This is why KTM, TM, and I guess "Honda" have all hinted at EFI/DI two strokes. Its had great success in the sled world and its currently working its way into GP racing, so whats the hold up?
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Here it is, The new Honda. ;)
EFI 2 Stroke.
(http://i864.photobucket.com/albums/ab207/tmkiwi/1435_p.jpg)
(http://i864.photobucket.com/albums/ab207/tmkiwi/1417_p.jpg)
(http://i864.photobucket.com/albums/ab207/tmkiwi/227568_2036945483703_1246222162_2425022_3918700_n.jpg)
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You are evil. >:D
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Here it is, The new Honda. ;)
EFI 2 Stroke.
(http://i864.photobucket.com/albums/ab207/tmkiwi/1435_p.jpg)
(http://i864.photobucket.com/albums/ab207/tmkiwi/1417_p.jpg)
(http://i864.photobucket.com/albums/ab207/tmkiwi/227568_2036945483703_1246222162_2425022_3918700_n.jpg)
What kind of bike is that? There are two different ones, because the one with red anodizing triples etc isn't too bad. I'd buy a bike like that to commute. 8) Italian? Colors on number plates is why I ask.
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Alittle confused to say the least. Those are Honda's. According to other pages, they have all sorts of bikes in Spain, that are being made with Honda info. http://translate.google.com/translate?hl=en&sl=es&u=http://www.motoocasionpro.com/ads/hm-crm-125-2t-derapage-competition-2011/&ei=NyvJTcL6JeLx0gHNuMmSCQ&sa=X&oi=translate&ct=result&resnum=4&ved=0CDUQ7gEwAw&prev=/search%3Fq%3Dhm%2Bcrm125%2B2011%26hl%3Den%26rls%3Dcom.microsoft:en-US%26rlz%3D1I7DKUS_en%26prmd%3Divns (http://translate.google.com/translate?hl=en&sl=es&u=http://www.motoocasionpro.com/ads/hm-crm-125-2t-derapage-competition-2011/&ei=NyvJTcL6JeLx0gHNuMmSCQ&sa=X&oi=translate&ct=result&resnum=4&ved=0CDUQ7gEwAw&prev=/search%3Fq%3Dhm%2Bcrm125%2B2011%26hl%3Den%26rls%3Dcom.microsoft:en-US%26rlz%3D1I7DKUS_en%26prmd%3Divns)
http://www.motorbikes.be/en/HM_CRM_125R_2007.aspx (http://www.motorbikes.be/en/HM_CRM_125R_2007.aspx)
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Those are pretty cool bikes. If you wanted a 2011 'Honda' that would be your place to buy. But I don't think anything would beat the real deal.
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So seems kinda like a service honda dealio. They get bikes and make them into new bikes? The supermotos are cool. $2999 euro's. Wonder how much here. Wish that sold here.
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I think you're beating a dead horse 2t institute.It reminds me of arguing all the reasons why an airplane will never fly.
BRP has already done it-the end.As bioflex says,it remains to be seen whether anyone will put it into production.Maybe BRP will do a dirt bike,under the Can Am name.That's certainly feasible if they see a market.
For all you who don't want to see it happen,you better hope it-or something else,does or I expect in a few short years you can kiss your 2t dirt bikes goodbye.
Been enjoying this thread...I had not to long ago spoken with a engine tuner friend about the DI issue. He told me how BRP built a 300cc DI 2T ATV to test and compare against the current 450 4T performance offering. It apparently out performed the 4T in every catagory and all test riders chose the 2T over the 4T. In the end, the brass said no because of consumer perception. So does BRP have the golden egg or perhaps even the goose.
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Here it is, The new Honda. ;)
EFI 2 Stroke.
(http://i864.photobucket.com/albums/ab207/tmkiwi/1435_p.jpg)
(http://i864.photobucket.com/albums/ab207/tmkiwi/1417_p.jpg)
(http://i864.photobucket.com/albums/ab207/tmkiwi/227568_2036945483703_1246222162_2425022_3918700_n.jpg)
What kind of bike is that? There are two different ones, because the one with red anodizing triples etc isn't too bad. I'd buy a bike like that to commute. 8) Italian? Colors on number plates is why I ask.
Pretty sure these are Hero Motorcycles. They had used Honda based engines. I thought I remember reading Honda broke ties with them a few years ago.
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Not sure, Hero isn't showing any 2 strokes and is a India based setup looks like. HM is coming up as spanish stuff. Very interesting and would like to know more.
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Thats HONDA-motesa think its a Spanish honda factory
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Sorry for the wind up guys. ;D
The bike is a HM from Italy.
Quote stolen from site I found this from.
Honda do not make any 2 stroke engines any more.
The HM CRE are actually bikes from motocross of Honda (the CR ) that once imported into Italy are prepared by the importer to HM 's enduro Europe. Infatti la sigla HM deriva dall' acronimo di Honda - Montesa . In fact, derives from the initials HM ' stands for Honda - Montesa .
The CRE, with two-stroke engine , were built in different sizes, just cross the models approved for the enduro.
. There is also a version built in Italy 50 cc call HM CRE 50 .
There are also models supermotard that differ in several details, which only in the 50 cc version were called Derapage and since 2007 have changed their name in CRM, while the higher capacity versions were called "Motard".
by 2008 only the CRE 50 has remained in production until 2010, in 2011 there is the return of a second displacement.
After a period where he left off in just the motorcycle production in 2011 was put into production at the 125 (presented at ' EICMA in 2010. In this new edition is equipped with the ECS of Dell'Orto (previously used by the Cagiva Mito and by ' Aprilia RS 125 ) with a Rotax engine block, otherwise it has the structure of the CRE 50 with slight differences for the suspension, The motion also adopts a cooling fan placed at the top right of the radiator, you also have the opportunity to enjoy two engine maps selectable from the handlebars.
The ECS used for this motion is characterized by various sensors, an indicator to signal a malfunction and an electronic oil pump, the exhaust valve just like the Aprilia is used to model the fixed and mobile for the weakened Model ? full power III.
The difference between the model and the Baja competition is that it does not use the mixer and the oil tank, but is powered by a gasoline-oil mixture, it also has double radiator, an ' expansion different and that even though the clutch cable has a hydraulically operated, this oil because it uses a drive-wire at the entrance of glazed paper.
Not a very good translation.
(http://i864.photobucket.com/albums/ab207/tmkiwi/1457_p.jpg)
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Alright! so where's a Italian two stroker to import these suns of beaches ;D I'll take the supermoto 125 with fuel injection. I'll ride it every day to work.
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Dumb question. With DI, how does the 2T bottom end get lubrication?
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Ahhhhh.....
"But DI can pose some lubrication challenges. Oil is still drawn in from the bottom of the cylinder but fuel is injected from the top. Since the fuel and oil don't mix, the oil isn't thinned sufficiently to move up and lubricate the top piston ring. That's a recipe for engine disaster-as one manufacturer has discovered.
Yamaha's HPDI system gets around this problem with a new, patented bottom piston ring that's made with a taper for oil bypass every 30 degrees. The 12 tapered areas around the ring allow sufficient oil to reach and lubricate the top ring."
http://www.popularmechanics.com/outdoors/recreation/boating/1276871 (http://www.popularmechanics.com/outdoors/recreation/boating/1276871)
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Oh my oh my...
A 125 2stroke Honda (altho under the name of Italian HM) with new Austrian Rotax 2 stroke technology.
Aprilia should have used this engine in the current RS125, insted of that 125 4 stroke...
I expect this engine also in go-karts, as the rotax 125 engine is very popular in karting.
Perhaps Aprilia will use this engine in their next years SX/RX 125. But for now, they still use the carbed Rotax 125.
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Dumb question. With DI, how does the 2T bottom end get lubrication?
You need an oil tank & pressure pump.
With no fuel running through the crankcase to wash off the oil you dont need as much oil.
Pressure pump supplys oil to the crank journals just like a 4 stroke ( oil gallerys to the big end & little end ) and also the ring using a nozzle in the side of the cylinder. You can also bleed a bit of oil into the fuel so it is injected into the combustion chamber.
Any excess oil is recirculated from the bottom of the crankcase using the crankcase pulses and a simple vacum pump and sent back to lubrication system.
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It's not any sort of DFI, or EFI. Just Dell'Ortos ECS - Electronic Carburetor System.
The ECS is just a Carb with some electrical components. I think a CV type unit with an electric oil pump / solenoid for auto lube, and a few other things, perhaps an electronic power jet. And I think the PV is simply opened by a solenoid, whilst still having some sort of diaphragm like the first Rotax PV set ups., and the Maico PV set up. Huskies Euro market WR125 - a DS version of the real WR125 uses this as well, as do a variety of road legal bikes and scooters.
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ETec! Want ETec! 1/2 of a 150 HP SkiDoo 2TDI 800.
70HP for a 400cc would be quite nice in a new KTM frame!
And would be clean enough for green sticker in California.
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Pretty wild. These articles are a little dated though.