Last ever 250 race

That is a great idea, would be nice to say goodbye to the 250cc era with style. Hope Dorna reads this!

Farkin' brilliant. Costs for your "idealised" plans could be offset by offering a DVD with a two hour long recap of 250s and riders down the years, culminating in the final tribute in Valencia... missed op if Dorna does diddley...

Arra, this (the final 250cc race) was actually something that I had overlooked given that 250cc does not have the high profile of MGP, so thanks for reminding as it will be a truly historic and dare I say sad day for the sport.

That said, what a great idea to have as many past 250cc champions as possible attend and parade their title winning bikes (where possible) and truly make a festival out of it.


Crap though, as I am now really not looking forward to Valencia as much as I lovet he two-smokes.








Gaz

I'm most saddened that the manufacturers refused to adopt clean two-strokes while lobbying governments around the world to look at the engine's mechanic simplicity and how good it is for societies that need cheap transportation products (fun recreation for the West). A vast majority of all 2 wheeled vehicles are scooters sold in the developing world. I'm upset that the FIM is canceling a historical class without giving any indication that they understand the importance of two stroke motorcycles.

Encouraging the major manufacturers to embrace direct injection two strokes would to a lot of good for future generations who grow up in the developing world. The technology is already widely used but the high pressure injectors need to be further developed for motorcycle use.

Not to be a bleeding heart or anything, but someone at the FIM has got to be practical and look at the real problems (not entertainment problems) within the world of motorcycling. China and India are not going to come out of poverty overnight so you've got to assume that another 40 or 50 years of scooting around rural roads and underdeveloped urban areas is a reality for citizens of the developing world. The manufacturers need a high profile clean two stroke class so they can use sponsorship money and commercial rights money to help bankroll development.

Not only is it the last one ever, it looks like it's going to be a cracking race, with Aoyama & Simoncelli. With the last championship up for grabs, they both are going to want to win this one badly. Not to be missed.

<div class='quotetop'>QUOTE (mylexicon @ Oct 30 2009, 04:02 AM) <{POST_SNAPBACK}><div class='quotemain'>I'm most saddened that the manufacturers refused to adopt clean two-strokes while lobbying governments around the world to look at the engine's mechanic simplicity and how good it is for societies that need cheap transportation products (fun recreation for the West). A vast majority of all 2 wheeled vehicles are scooters sold in the developing world. I'm upset that the FIM is canceling a historical class without giving any indication that they understand the importance of two stroke motorcycles.

Encouraging the major manufacturers to embrace direct injection two strokes would to a lot of good for future generations who grow up in the developing world. The technology is already widely used but the high pressure injectors need to be further developed for motorcycle use.

Not to be a bleeding heart or anything, but someone at the FIM has got to be practical and look at the real problems (not entertainment problems) within the world of motorcycling. China and India are not going to come out of poverty overnight so you've got to assume that another 40 or 50 years of scooting around rural roads and underdeveloped urban areas is a reality for citizens of the developing world. The manufacturers need a high profile clean two stroke class so they can use sponsorship money and commercial rights money to help bankroll development.

I'm glad someone agrees, for years Evinrude have been developing their trick E-tec 2 stroke motors that use raft of electronic to actually not allow fuel into the combustion chambers until its clearer the exhaust port, this the emmisions aren't much worse that a 4, and you get a much better power to weight ratio.

http://www.evinrude.com/en-US/E-Tec/Techno...red.Technology/

<div class='quotetop'>QUOTE (mylexicon @ Oct 30 2009, 11:02 AM) <{POST_SNAPBACK}><div class='quotemain'>I'm most saddened that the manufacturers refused to adopt clean two-strokes while lobbying governments around the world to look at the engine's mechanic simplicity and how good it is for societies that need cheap transportation products (fun recreation for the West). A vast majority of all 2 wheeled vehicles are scooters sold in the developing world. I'm upset that the FIM is canceling a historical class without giving any indication that they understand the importance of two stroke motorcycles.

Encouraging the major manufacturers to embrace direct injection two strokes would to a lot of good for future generations who grow up in the developing world. The technology is already widely used but the high pressure injectors need to be further developed for motorcycle use.

Not to be a bleeding heart or anything, but someone at the FIM has got to be practical and look at the real problems (not entertainment problems) within the world of motorcycling. China and India are not going to come out of poverty overnight so you've got to assume that another 40 or 50 years of scooting around rural roads and underdeveloped urban areas is a reality for citizens of the developing world. The manufacturers need a high profile clean two stroke class so they can use sponsorship money and commercial rights money to help bankroll development.
.... - that was surprisingly lucid AND I agree with it... Logical, simple and do-able... I hope someone recognizes the potential while the 125s are still around (very "size appropriate" for scooterists) and takes advantage of the business potential of such a scheme.

Great post Arrab. I have been lamenting the demise of the 250 class at every race this year. Not only has it be the breeding ground of so many champions over the years, it's arguably been the most exciting class to watch for the race fan. It really would be a shame if Dorna, FIM, and the manufacturers did nothing to celebrate all those decades of 250 racing. I hope they had the foresight to plan something.

<div class='quotetop'>QUOTE (#22 @ Oct 30 2009, 07:18 PM) <{POST_SNAPBACK}><div class='quotemain'>I'm glad someone agrees, for years Evinrude have been developing their trick E-tec 2 stroke motors that use raft of electronic to actually not allow fuel into the combustion chambers until its clearer the exhaust port, this the emmisions aren't much worse that a 4, and you get a much better power to weight ratio.

http://www.evinrude.com/en-US/E-Tec/Techno...red.Technology/


I take it you think an Evinrude is more advanced than a 250 GP bike

I love two strokes and have ridden more than most one here and for much longer, and probably still own more than most one here, but they are dead.

A clean two stroke is sadly also a very low torque two stroke. As an example DI obliterates the benefit that the expansion chamber made. And just remember how bikes were before that. They'll be lean burn versions of lawn mowers.

Besides "clean burn" is only part of the equation these days, theres also work done per volume of fuel used ....... thats where two strokes are copping it.

<div class='quotetop'>QUOTE (bonnielass @ Oct 30 2009, 08:14 AM) <{POST_SNAPBACK}><div class='quotemain'>Not only is it the last one ever, it looks like it's going to be a cracking race, with Aoyama & Simoncelli. With the last championship up for grabs, they both are going to want to win this one badly. Not to be missed.
And we've got another Brit to cheer for.

http://news.bbc.co.uk/sport1/hi/motorsport/8320991.stm

<div class='quotetop'>QUOTE (bonnielass @ Oct 30 2009, 04:14 AM) <{POST_SNAPBACK}><div class='quotemain'>Not only is it the last one ever, it looks like it's going to be a cracking race, with Aoyama & Simoncelli. With the last championship up for grabs, they both are going to want to win this one badly. Not to be missed.

Unfortunatley,that is probably not the case.All Aoyoma needs to do to secure the title is finish, i believe in 11th spot. With predator heads history of booting riders off the track, i look for Aoyoma to pull a Spies and stay safe.

Lets get all these non-environment friendly bikes and put them in a pile and burn them o-zone killing .......s!!!!!!!!!!!!!!
























Peace & love,
Tree hugging hippie ......

ps. Save the whales!!!

Oh Yeah!! Hiroshi Aoyama will go down in the history books as the last 250cc Moto Champion!! Eat that haters.

<div class='quotetop'>QUOTE (MdubSTYLIE @ Oct 30 2009, 10:10 PM) <{POST_SNAPBACK}><div class='quotemain'>Lets get all these non-environment friendly bikes and put them in a pile and burn them o-zone killing .......s!!!!!!!!!!!!!!
Peace & love,
Tree hugging hippie ......

ps. Save the whales!!!

<div class='quotetop'>QUOTE (BarryMachine @ Oct 30 2009, 03:00 PM) <{POST_SNAPBACK}><div class='quotemain'>I take it you think an Evinrude is more advanced than a 250 GP bike

In terms of electronic & emission controls, yes thats what i'm stating

<div class='quotetop'>QUOTE <div class='quotemain'>I love two strokes and have ridden more than most one here and for much longer, and probably still own more than most one here, but they are dead.

A clean two stroke is sadly also a very low torque two stroke. As an example DI obliterates the benefit that the expansion chamber made. And just remember how bikes were before that. They'll be lean burn versions of lawn mowers.

Besides "clean burn" is only part of the equation these days, theres also work done per volume of fuel used ....... thats where two strokes are copping it.

I have to disagree with you here. While I do agree that like for like, a 2/ will never be as clean emissions wise as a 4/, they are far from 'dead' as you put it.
Your statement of a 'clean burn' 2/ being a low torque motor is incorrect as the expansion chamber develops the pulse waves and back pressure that allow the waste gasses to scavenge and exit the combustion chamber through the exhaust port more effectively and as Direct Injection has nothing to do with these air pulses (the DI system simply injects fuel in after the piston has risen enough to close the exhaust port and thus eliminates the polution caused by a conventional motor), it has no effect.
The exhaust port and following expansion chamber are one of the most critical points of 2/ engines and developing power. Ideally a wide exhaust port is desirable but this causes excessive cylinder & piston ring wear causing relaibility issues. A narrower, taller exhaust port eradicates this issue but then leaves the engine with a an unnaceptably narrow and peaky powerband. So say this is the issue you claim to be caused by using direct injection, the way around it? Use a powervalve system that alters the height of the exhaust port according to engine running conditions which gives the benefits of a wide exhaust port but without the narrow power band of a taller, narrower one. This way the valve can be closed off to reduce the port height and improve mid-range power. This also works by adjusting the resonant frequency of the expansion chamber and thus the reflected pressure wave on the fuel charge.

If, by "work per volume of fuel used" you are referring to Volumetric Efficiency, two strokes don't suffer as much as you think, and with modern expansion chamber designs being ingenious enough to return the escaping air/fuel mix back into the cylinder (not including DI engines), then its possible that the GP motors are actually producing volumetric efficiencies in excess of 100%
Finally, the definition of VE is 'The efficiency at which charge (air/fuel mix) can be moved into and out of the cylinders'. DI would not have a great effect on this if the system was position correctly and if anything, would improve it. Another thing to note is engines with a high volumetric efficiency will be able to run at higher speeds. As per 2 strokes.

I know you have ridden a lot of two strokers, but it seems your knowledge needs updating.

<div class='quotetop'>QUOTE (BarryMachine @ Oct 30 2009, 08:00 AM) <{POST_SNAPBACK}><div class='quotemain'>I take it you think an Evinrude is more advanced than a 250 GP bike

I love two strokes and have ridden more than most one here and for much longer, and probably still own more than most one here, but they are dead.

A clean two stroke is sadly also a very low torque two stroke. As an example DI obliterates the benefit that the expansion chamber made. And just remember how bikes were before that. They'll be lean burn versions of lawn mowers.

Besides "clean burn" is only part of the equation these days, theres also work done per volume of fuel used ....... thats where two strokes are copping it.

I'm somewhat confused by this as well. Modern DI allows for a pressurized injection of air and fuel into the cylinder and it can be timed so that the air/fuel is injected after the exhaust port is closed. Unforunately, it is hard to get air/fuel DI to run at high rpm. It also doesn't work terribly well on small engines (50cc) because the engine can't generate enough pressure to atomize the fuel (I've read) without robbing too much of the engines power.

The other style of DI still relies on air from the crankcase and some version still use the expansion chamber to keep fresh air in the cylinder. The fuel is injected after the exhaust valve is closed. It is exactly the same as a conventional two stroke, but it doesn't burn oil. It still has all of the performance issues like a narrow power band.

To celebrate just pour some Castor oil on your head and see what it does for your shoes. Ya, there is no up side. Time for a change. At the same time switch to pure ethanol. Then, I'd be impressed.

<div class='quotetop'>QUOTE (#22 @ Oct 31 2009, 10:22 AM) <{POST_SNAPBACK}><div class='quotemain'>In terms of electronic & emission controls, yes thats what i'm stating



I have to disagree with you here. While I do agree that like for like, a 2/ will never be as clean emissions wise as a 4/, they are far from 'dead' as you put it.
Your statement of a 'clean burn' 2/ being a low torque motor is incorrect as the expansion chamber develops the pulse waves and back pressure that allow the waste gasses to scavenge and exit the combustion chamber through the exhaust port more effectively and as Direct Injection has nothing to do with these air pulses (the DI system simply injects fuel in after the piston has risen enough to close the exhaust port and thus eliminates the polution caused by a conventional motor), it has no effect.
The exhaust port and following expansion chamber are one of the most critical points of 2/ engines and developing power. Ideally a wide exhaust port is desirable but this causes excessive cylinder & piston ring wear causing relaibility issues. A narrower, taller exhaust port eradicates this issue but then leaves the engine with a an unnaceptably narrow and peaky powerband. So say this is the issue you claim to be caused by using direct injection, the way around it? Use a powervalve system that alters the height of the exhaust port according to engine running conditions which gives the benefits of a wide exhaust port but without the narrow power band of a taller, narrower one. This way the valve can be closed off to reduce the port height and improve mid-range power. This also works by adjusting the resonant frequency of the expansion chamber and thus the reflected pressure wave on the fuel charge.

If, by "work per volume of fuel used" you are referring to Volumetric Efficiency, two strokes don't suffer as much as you think, and with modern expansion chamber designs being ingenious enough to return the escaping air/fuel mix back into the cylinder (not including DI engines), then its possible that the GP motors are actually producing volumetric efficiencies in excess of 100%
Finally, the definition of VE is 'The efficiency at which charge (air/fuel mix) can be moved into and out of the cylinders'. DI would not have a great effect on this if the system was position correctly and if anything, would improve it. Another thing to note is engines with a high volumetric efficiency will be able to run at higher speeds. As per 2 strokes.

I know you have ridden a lot of two strokers, but it seems your knowledge needs updating.


You know 2 stroke development had peaked over 10 years ago.

DI is as old as the hills.

Computers are old.

By suggesting they are getting in excess of 100% efficiency you do realise you may have invented the perpetual motion machine!!!!! I'd rush out and patent that right now



All that being said I think theres still a place for 2 strokes in outboards, ie. they are inherently more corrosion resistant. ( though I note they aren't like my old Johnson 40:1 fuel/oil jobby here! And if we look at just corrosion resistance. If the modern motors anren't lasting as long then it takes more energy to make new ones ...... etc. etc. etc. ...... folk have tried to do such evaluations but meh, they never seem reasonable to me.


No Evinrude/Yamaha/Tohatsu ........ they are "plunkers" based on technology that peaked years ago. I also think that they are fighting their cause using the wrong arena.

Its no use talking efficient DI and use of expansion chambers to me ..... it a nonsense, chambers were a device we who lived in the days of 20c a gallon could afford

You may say but I can afford to fuel it ........... but how much is it costing, and using up fuel reserves quicker, when there are several million "us" wasting just that little bit

We are in the "runout" days of fossil fuels, running engines that throw away tiny bits is no longer acceptable. Even the racing fraternity finally accepted that "yeah we use fuel, and have fun doing it!" and it does look wasteful" was no longer an arguement, cos its now down to how many more years left you have to have that fun.

But hey! never fear ..... electrics here!!

<div class='quotetop'>QUOTE (BarryMachine @ Oct 30 2009, 06:06 PM) <{POST_SNAPBACK}><div class='quotemain'>But hey! never fear ..... electrics here!!

Yey. Let's throw millions of tons of toxic batteries into land fills every year in order to avoid keeping the oceans clean so phytoplankton populations can return. I remember when batteries were bad and parents were chastised by the news media for buying battery operated Christmas toys for their children. Now giant 400lb batteries are the savior of the planet. Go figure.

We're not anywhere close to being out of oil, and CO2 is tree oxygen so I don't see it as a dirty pollutant. We can cut CO2 to 0 and still not make any improvement b/c of global phytoplankton levels. Electrics aren't going to do anything but soothe eco-angst.

We don't need to discard 100 years of ICE development. We need to engineer a new fuel that is either carbon neutral or doesn't release CO2 when it is burned. We are already pretty close.