Rumours,Rumours!

[2T Institute]

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.

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.

[TotalNZ]

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.

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

[VintageBlueSmoke]

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.

[MyckMcClung]

 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?

[teriks]

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.

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?

[VintageBlueSmoke]

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...

[monsteryz125]

Alright i was just on facebook and insidermx posted a link to the 2012 honda models and not a single 2 stroke

[EJ]

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...

[MyckMcClung]

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

[TMKIWI]

(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.

[VintageBlueSmoke]

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.

[2T Institute]

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.

[factoryX]

Hold up there buddy 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.   If most of you would read some of the EFI sled reviews you would know this.

[SachsGS]

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.

[miedosoracing]

Hold up there buddy 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.   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.