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125's and 250's: One make series?

<div class='quotetop'>QUOTE (teomolca @ Nov 29 2006, 12:12 PM) <{POST_SNAPBACK}><div class='quotemain'>1. A high tech 4+ cyl 250cc with modern Michelins and carbon discs and all the electronic aids would make 990cc 4strokes look like elephants on ice compared to them.

2.And many times in the past the 250cc were quicker than 500cc, it just takes a twisty track with many corners and short straights.

3.Remember a 2 stroke is a real racing engine

1. I very much doubt that, they're most likely put down to 2 cyl's for a reason, and a 250-4cyl 2-smoke with carbon brakes and Michelins would not keep anywhere near a 990 RC211V.

2. Yes, but you are talking about an era that is gone, now is the 4-stroke era, it doesn't matter they were faster because there were more corners and less straights.

3. Although I somewhat agree with that statement, what is your proof it's a 'real' racing engine? I think 990 V5's are the epitomy of racing engines so I suppose it is down to an opinion...they're both differant engine types.
 
<div class='quotetop'>QUOTE (teomolca @ Nov 29 2006, 11:12 PM) <{POST_SNAPBACK}><div class='quotemain'>No, take for example Sachsenring,in 2002 the brand new MotoGPs were barely 1 second faster than 250cc in that track, that's with 250cc being restricted to 2 cylinders, iron brake disks, crap Dunlop tyres and supposedly worse riders than MotoGP. Since then the gap has increased, but so have the difference in budgets and restrictions. A high tech 4+ cyl 250cc with modern Michelins and carbon discs and all the electronic aids would make 990cc 4strokes look like elephants on ice compared to them.

And many times in the past the 250cc were quicker than 500cc, it just takes a twisty track with many corners and short straights.

Remember a 2 stroke is a real racing engine

You make some intresting points there, Teo. But I'm sure there's more to it than that. Remember, in 2002 the 990s were babies, only at the beginning of thier development stage. I know more money and time has been put into them now, but you can't expect a new bike to be fast out of the box.
I guess it depends on the budget, like I said before. A 4 stroke prototype needs a lot of money to go fast, a 250 dosen't (In comparison), so below a certain figure (I don't know what it is, HRC aren't exactly public about their accounting) you could develop a faster 250, but if you set that restricted budget to an astronomical amount and told the engineer to "Just build the fastest bike you can", I think the 800 would come out on top. I know there's a lot more to it than this, but considering Power and Weight (The basic building blocks of fastness) A four stroke engine is going to be heavier, but what's it got that a 2 stroke hasn't? An oil system and a valvetrain, right? If you were building a race bike outta the most whiz bang, super strong/light materials that NASA found in the moon, how much is a few springs, some valves and a couple of cams gonna weigh in at? Then there's the oil system to take into account, and the oil itself can't be made lighter, but two strokes carry a supply of oil too. The four stroke would also give away weight in other areas like the reqirement of a stronger chassis to hold a fatter engine, so the two stroke will have it's nose in front in the weight department, but how much would it be considering the entire weight of the bike? I know every kilo counts, but is its gonna be a wipe-the floor advantage on a fully loaded bike plus 60 odd kilos of Spanish/Italian meat and talent in the seat? I belive the superior power of the four stroke would make it a winner. Remember, you said a 250 against a MotoGP bike. Regardless of whether it's a 990 or an 800, it's gonna make more power. In theory, 2 strokes should be able to make 100% more power than a four stroke, in practice, you yourself have said it's closer to 70%. That makes a 250cc 2 stroke engine the equivalent of a 425cc four stroke, or a 500 in a perfect world. That gives away at least 300cc to the prototype. Which, going by numbers is a 60% advantage for the four stroke. A two stroke might be able to get a weight advantage over a four stroke, but will it be in the vicinity of 60%? I don't think so. A four stroke will also have a smoother power curve, which is an advantage for the rider.
It would also depend on the track. 250s have gone faster than MotoGP bikes IIRC, in the right conditions. A 250 would thrash a 990 on a go kart track, but if the made a raceway out of an airport runway, the 250 wouldn't be anywhere near as scary. That's how I see it anyway. I know it's all theory and on-paper stuff, but we're never gonna get to see it put to the test in practice anyway. The reality is, Honda dosen't like two strokes. And When Honda dosen't like somthing, it hasn't got a chance. Just as Max Biaggi or a 500
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I guess it comes down to prefrence. I agree that a two stroke naturally makes a better race engines, but the MotoGP prototypes aren't natural. They're incredibly amazing machines, and in my opinion, they're better racebikes than any two-stroke powered motorcycle.
 
You said it yourself Richo, depends on the track, the aim is not making the 250cc engine as powerful as the 990cc that's almost impossible, the aim is to combine the agility of the light 250cc bike with a more powerful engine (160~180hp should be possible), THAT would beat MotoGPs in Sachsenring like tracks, and it doesn't matter how much hp the MotoGP has, they would still lose even if they had 300hp.

<div class='quotetop'>QUOTE <div class='quotemain'>1. I very much doubt that, they're most likely put down to 2 cyl's for a reason, and a 250-4cyl 2-smoke with carbon brakes and Michelins would not keep anywhere near a 990 RC211V.

2. Yes, but you are talking about an era that is gone, now is the 4-stroke era, it doesn't matter they were faster because there were more corners and less straights.

3. Although I somewhat agree with that statement, what is your proof it's a 'real' racing engine? I think 990 V5's are the epitomy of racing engines so I suppose it is down to an opinion...they're both differant engine types.

1. The reason why they stick to 2 cyls maximum is because the rules say so (to keep the costs low), there's no technical reason for not using 4 or more cyls. And yeah you're right, in the appropiate track those 250cc would be nowhere near the MotoGP ... because they would be so far ahead they wouldn't see them!

2 It was just an example of how having twice the horsepower is totally irrelevant in that case and it can perfectly be extrapolated to the MotoGP vs unlimited 250cc scenario.

3. It's about 10% lighter and 70% more powerful given the same displacement. Point Proved.
 
wishes rep system was introduced

Great post Richo!

+1!
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<div class='quotetop'>QUOTE (teomolca @ Dec 1 2006, 11:09 AM) <{POST_SNAPBACK}><div class='quotemain'>You said it yourself Richo, depends on the track, the aim is not making the 250cc engine as powerful as the 990cc that's almost impossible, the aim is to combine the agility of the light 250cc bike with a more powerful engine (160~180hp should be possible), THAT would beat MotoGPs in Sachsenring like tracks, and it doesn't matter how much hp the MotoGP has, they would still lose even if they had 300hp.
1. The reason why they stick to 2 cyls maximum is because the rules say so (to keep the costs low), there's no technical reason for not using 4 or more cyls. And yeah you're right, in the appropiate track those 250cc would be nowhere near the MotoGP ... because they would be so far ahead they wouldn't see them!

2 It was just an example of how having twice the horsepower is totally irrelevant in that case and it can perfectly be extrapolated to the MotoGP vs unlimited 250cc scenario.

3. It's about 10% lighter and 70% more powerful given the same displacement. Point Proved.

Actually, the bigger a two stroke engine is, the ....... it gets, or so I've heard...something along the lines of the larger a two stroke engine gets, the more inefficient it becomes.

If you had a 500cc V4 4-stroke and put massive amounts of dosh into it, you could make it beat a 500 V4 2-stroke...just you'd be filthy poor at the end!
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Are you seriously telling me,that around a track like,say Donington Park, that a 250 with a few more cylinders, sticky tires and electronics (WHICH THEY DON'T NEED) could beat one of the old 990's? If so you're mad!
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I would be a bit biased though, I despise two strokes with a passion, bad experiences and all.

Edit, I saw your 180 bhp quote for an unlimited 250, correct me if I'm wrong, but weren't unlimited 500's stuggling to make that?!
 
Just my thoughts but I`d like to see 125`s replaced by 600cc prototype singles and 250`s replaced by 500cc 4`s/600cc triples ,,again prototypes,but there would need to be some kind of cap on the budgets to keep it even-ish.I`m sure there will be a lot of pro`s and cons for this idea so do share them with us you tech heads.
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<div class='quotetop'>QUOTE (DRILL666 @ Dec 2 2006, 08:14 AM) <{POST_SNAPBACK}><div class='quotemain'>Just my thoughts but I`d like to see 125`s replaced by 600cc prototype singles and 250`s replaced by 500cc 4`s/600cc triples ,,again prototypes,but there would need to be some kind of cap on the budgets to keep it even-ish.I`m sure there will be a lot of pro`s and cons for this idea so do share them with us you tech heads.
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drill i'd have to think that this, eventually, will happen in the future. it's already happening in mx. surely it's just a matter of time. 2 strokes are going away everywere.
 
The 250s are faster than big bikes arguement is great on paper but falls down on the track.

When Honda introduced the V2 NSR 500(which worked on this theory, it went brilliantly pre season and in qualifying. The problem came that its lap times were down to corner speed, and the V4s were flat out in a straight line, stop it turn it and get it upright ASAP! The fours just blocked the twins on the corners and the drag race to the next corner was a foregone conclusion, the V2s couldnt argue with the V4s at that game. But there is no dispute, the 250s are seriously fast, but its the corners that knacker them against the motogp bikes.

Pete
 
<div class='quotetop'>QUOTE (frosty58 @ Dec 2 2006, 03:51 PM) <{POST_SNAPBACK}><div class='quotemain'>drill i'd have to think that this, eventually, will happen in the future. it's already happening in mx. surely it's just a matter of time. 2 strokes are going away everywere.
Right on the button,Frosty bro,
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<div class='quotetop'>QUOTE (phleg @ Dec 1 2006, 12:20 PM) <{POST_SNAPBACK}><div class='quotemain'>Actually, the bigger a two stroke engine is, the ....... it gets, or so I've heard...something along the lines of the larger a two stroke engine gets, the more inefficient it becomes.
It's the size of the cylinder what matter not the total displacement, i.e. a 250cc single is more efficient that a 500cc single (it also applies for 4 strokes)

<div class='quotetop'>QUOTE <div class='quotemain'>If you had a 500cc V4 4-stroke and put massive amounts of dosh into it, you could make it beat a 500 V4 2-stroke...just you'd be filthy poor at the end!
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No you can't, Honda tried that in the 80's with the NR500, revolutionary high tech 4stroke that got humilliated by the 2strokes.

<div class='quotetop'>QUOTE <div class='quotemain'>Are you seriously telling me,that around a track like,say Donington Park, that a 250 with a few more cylinders, sticky tires and electronics (WHICH THEY DON'T NEED) could beat one of the old 990's? If so you're mad!
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I don't know about Donnnington park, I'm not too familiar with the track, but you bet at Sachsenring or Valencia probably the 250cc would win, and about electronics, you bet they'll need them.

<div class='quotetop'>QUOTE <div class='quotemain'>I saw your 180 bhp quote for an unlimited 250, correct me if I'm wrong, but weren't unlimited 500's stuggling to make that?!
No, HRC acknowledged 200hp for the 2000 NSR, so probably it had a few more, I'd say around 210.
 
<div class='quotetop'>QUOTE (Teo's Alias @ Dec 3 2006, 09:23 PM) <{POST_SNAPBACK}><div class='quotemain'>No you can't, Honda tried that in the 80's with the NR500, revolutionary high tech 4stroke that got humilliated by the 2strokes.

Erm, how advanced was 4-stoke technology back then?
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Who had EVER tried using oval pistons in a bike?

I don't know about Donnnington park, I'm not too familiar with the track, but you bet at Sachsenring or Valencia probably the 250cc would win, and about electronics, you bet they'll need them.

Are you seriously saying that you think a 250 could beat a moto gp bike?
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Why don't they race against each other then? And a 250 doesn't need electronics, how much wheelspin do they have compared to the 990's? Not very much (unless McCoy is on board)

No, HRC acknowledged 200hp for the 2000 NSR, so probably it had a few more, I'd say around 210.

Fair enough, I guess I was proved wrong on that point.

Sorry if I got me quotes messed up.
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800's are faster than 990 already and two strokes are being replaced anyway(in a long time), so I guess one day this discussion may become irrelevant.
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<div class='quotetop'>QUOTE (phleg @ Dec 1 2006, 11:20 AM) <{POST_SNAPBACK}><div class='quotemain'>If you had a 500cc V4 4-stroke and put massive amounts of dosh into it, you could make it beat a 500 V4 2-stroke...just you'd be filthy poor at the end!
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not to sure i agree with that mate, if you put masive amounts of dosh into the 4 stroke and used an old 2 stroke from about 10 years ago i still dont think you could do it.
dont get me wrong ,i love 4 strokes but would not object to see'ing 2 strokes back in the premier class aswell.
the problem with 4 strokes is the amount of moving parts,now radial moving parts are not to much of a problem like cams crank ect but its the resipricating parts that limit the 4 engines rev ceiling,parts like the conrod and valves. now they can use pnewmatics and desmos to prevent valve spring surge but the fact remains the part has to stop twice in its cicle, once at open and once at close possision,this is the problem.
a 2 stroke is still a resipricating engine but only has the piston and 2/3 of the conrode that is concidered to be resipricating thus a higher rev cieling can be achived. the 2 stroke is also lighter so less giroscopics. the 2 stroke is by no means perfect though. there problem is intake and exaust ports are open at the same time in part of its cicle,this is why you see petrol dripping out of the exaust,they try to counter this by useing "shnurls loop "effect which trys to direct the fresh charge away from the exaust port,so 2 strokes are insefficnt.
i think for a 500 4 stroke to make the same power as a 500 2 stroke the 4 stroke would need to rev to 50-60,000 rpm (there at about 20,000 at the moment) but i dont think this is possable because of the speed in which petrol burns,this is why dragsters use nitromethaine. dont think motogp is ready for that.
 
Good post.

I don't think your 50-60k rpm is accurate though... these 800's are a 200cc drop and lose only 20ish bhp (apparently the duc is making 220bhp) and they are lapping FASTER than the old gp bikes, in a few years time you could yet again drop the engine size and they'd either be the same speed or a bit slower.
 
<div class='quotetop'>QUOTE (phleg @ Dec 5 2006, 11:40 AM) <{POST_SNAPBACK}><div class='quotemain'>Good post.

I don't think your 50-60k rpm is accurate though... these 800's are a 200cc drop and lose only 20ish bhp (apparently the duc is making 220bhp) and they are lapping FASTER than the old gp bikes, in a few years time you could yet again drop the engine size and they'd either be the same speed or a bit slower.
ok 50-60k rpm was a tatal guess,but i came to that ball park figure because the 990's rev to about 17500rpm-20,000 rpm and given the fact that 4 stroke engines have more internal friction sapping power and half as many power stroke per rpm.
one point to remember though is ,quite often one technology is held back until another technology catches up.
ie ,an engineer may be able to build a high reving engine but is there a fuel available that will burn at that speed without detonating and are there pumps available to pump the fuel at that pressure and speed to cope. this is why there are not many direct injection petrol engines. you see you can pump diesel at high pressure because its an oil but petrol being a solvent tends to wear the injectors out to quickly and probably lot of other problems to.
but any thing is possable when your racing prototypes ,thats why i love it.
 
I agree with Fatty Snakeman Roger. I do belive that four stroke prototypes are superior to 2 stroke GP motorcycles, but not at the same displacement. As Rog pointed out, fuel cant burn that fast, steel can't move that fast blah blah blah. Two strokes have a huge advantage in their simpliclty. (Which is why Honda hates them, because only like things that are fast AND complicated.) Although they are filthy, inefficient mongrels, they put out (How bad does that sound?
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) It's simple math, a four stroke can beat a two stroke, but the four stoke needs a displacement advantage. Maybe a day will come when they don't need that advantage, but I'd say that day is so far off, when it comes internal combustion engines on a whole will be so old that only Russians will still be using them.
 
<div class='quotetop'>QUOTE (richo @ Dec 7 2006, 03:36 AM) <{POST_SNAPBACK}><div class='quotemain'>I agree with Fatty Snakeman Roger.

but I'd say that day is so far off, when it comes internal combustion engines on a whole will be so old that only Russians will still be using them.
OI ive told you before ,im not fat im big boned
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and dont forget india,they will still use them for the next 300 years too.
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