2-strokes in MotoGP?

[mhbarber]

It seems that the current crop of Moto GP bikes are outputting ~ 190 Kw.
If the teams had kept developing the 500cc stink-wheels, could they be putting out the same power? I'm not sure if technological similarities can be drawn with the just deceased 125's? Did they continue to get more powerful from 2002 ?

[Mental Trousers]

The rules could actually be changed to allow 2 strokes and any other sort of engine because the two main ones are

maximum fuel capacity per race
number of engines per season


Remove the 4 stroke 1000cc rule and it'd be a true prototype series again.

[haydes55]

The rules could actually be changed to allow 2 strokes and any other sort of engine because the two main ones are

maximum fuel capacity per race
number of engines per season


Remove the 4 stroke 1000cc rule and it'd be a true prototype series again.



That would be good! Imagine a 1400cc bike overtaking bikes like crazy down the straight, then the 1100s who lost down the straight, then get past them through the corners.

[AllanB]

A 'excess oil injection' button on the left bar would be the ticket - pass them, hit the button and smoke the buggers out.

[Robert Taylor]

It seems that the current crop of Moto GP bikes are outputting ~ 190 Kw.
If the teams had kept developing the 500cc stink-wheels, could they be putting out the same power? I'm not sure if technological similarities can be drawn with the just deceased 125's? Did they continue to get more powerful from 2002 ?

A 1 litre 2 stroke is going to produce more power than a 1 litre half time engine................

[Mental Trousers]

... and use twice as much fuel.

[BMWST?]

A 1 litre 2 stroke is going to produce more power than a 1 litre half time engine................

and use twice as much fuel at full chat

[ellipsis]

and use twice as much fuel at full chat

...as we are in dream world...so what...

[gammaguy]

A 'excess oil injection' button on the left bar would be the ticket - pass them, hit the button and smoke the buggers out.

Ummmm no.....that would just seize it

[Drew]

... and use twice as much fuel.Not in real life, provided they were using injection.

380Kw from a 1000cc two stroke isn't realistic for the application. They have to manage a whole race, and more.

A forced induction two stroke, with four stroke like heads and valve gear is the action. But then you need tanked air for idle and low revs, and the weight starts a climbin' up pretty quick. Wouldn't need to burn oil though.

[Mental Trousers]

There's lots of clean burning direct injection 2 strokes out there. The big problem was they never made it into racing because of weight, complexity, cost and they need some sort of forced induction.

Would be great to see not just 2 strokes in MotoGP but any other type of engine, eg an efficient and durable rotary. It could be done using the fuel consumption and number of engines rules.

[quickbuck]

eg an efficient and durable rotary. LOL If there is ever such a thing;)


It could be done using the fuel consumption and number of engines rules.
Well... if you increase the numbers significantly.....

Sorry couldn't resist......

But yeah, if you could get a gas turbine to use snaff all fuel that would make it interesting too... the 95dB limit (or is that 105?) would have to be increased to about 130!!

[Drew]

There's lots of clean burning direct injection 2 strokes out there. The big problem was they never made it into racing because of weight, complexity, cost and they need some sort of forced induction.

Would be great to see not just 2 strokes in MotoGP but any other type of engine, eg an efficient and durable rotary. It could be done using the fuel consumption and number of engines rules.
Direct injection only gets you so far with a two stroke. If I've learned anything from the Team ESE thread, it's that the exhaust scavenging system for the intake to work is the limiting factor. So camchain, valves, and pressurized inlet is one way to get around it.

In the model in my head, two pump systems for induction is best rather than a tank . Solid drive to get it running down low, (supercharger), and pressure driven for the higher revs, (turbo charger).

That way, the narrow power spread can be overcome too. And ya don't have to burn oil.

[F5 Dave]

There's lots of clean burning direct injection 2 strokes out there. The big problem was they never made it into racing because of weight, complexity, cost and they need some sort of forced induction.. . ..

. . .and the rules forbade it (hey that's probably the first time I've used that word). The FIM in their infinite wisdom, presumably as they were giving handies under the sheets to the Evil empire (H*nda) wanted to make sure 2 stroke performance increase was stifled as much as possible. Honda did actually test FI, but not direct injection.

Cost? you're kidding me? compared to now you could throw heaps at a 2 stroke & still not come close. Injection has shown decent fuel useage decreases.

[Mental Trousers]

Cost? you're kidding me? compared to now you could throw heaps at a 2 stroke & still not come close. Injection has shown decent fuel useage decreases.

They don't cost much now but a wee while back Direct Injection cost craploads. Costs come down significantly once a manufacturer gets something out to the masses, but before then it's farken expensive.

[steveyb]

Here ya go, this'll do ya.

http://en.wikipedia.org/wiki/Two-stroke_diesel_engine

[slowpoke]

In the model in my head, two pump systems for induction is best rather than a tank . Solid drive to get it running down low, (supercharger), and pressure driven for the higher revs, (turbo charger).

That way, the narrow power spread can be overcome too. And ya don't have to burn oil.


Here ya go, this'll do ya.

http://en.wikipedia.org/wiki/Two-stroke_diesel_engine

Dr Steve's on to it Drew, I remember years and years ago working on old Detroit (EMD) 2 stroke diesel gensets that used a turbocharger/supercharger combo.

[Drew]

Dr Steve's on to it Drew, I remember years and years ago working on old Detroit (EMD) 2 stroke diesel gensets that used a turbocharger/supercharger combo.

The theory is pretty simple. Timing is an issue, in that the exhaust still needs to be a hole in the bore. Opening the inlet early to complete the evacuation is simple, but the overlap needs to reduce as the revs and boost climb I should think. So a BMW rip off sliding cam perhaps.

Shit, the exhaust port can't be open until the piston skirt covers it. Otherwise all the oil ya don't need to burn anymore, is gonna make a break for it...hmmm. Obvious weak spot in the workings of my imaginary motor.

Someone with a clue, build this for me please. I'm not bright enough.

Oh, I'm well aware that two stroke diesel engines already work. But they're not trying to make masses of power and revs. Just torque over a narrower rev spread than a KX80

[BMWST?]

Rotary valves a la kawasaki etc,they can open and close indepedently of piston timing

from the tag

[Metastable]

Remove the 4 stroke 1000cc rule and it'd be a true prototype series again.

TRUE.... oh and toss the semiauto trany and have a stock ECU with little brain power so that they can't use traction control... unlimited fuel... keep the spec tires.

Then you end up with a situation where they can get more power than they can use... then the best rider starts to play more of a factor as opposed to just the guy who is merely precise at steering.

(don't get me wrong, the current crop are amazing riders.... and might still be the ones on top without all the rider aids)

[mr bucketracer]

why do you call the 2 strokes prototypes ? and not the 4 stroke motor gp bikes?

[Dave-]

why do you call the 2 strokes prototypes ? and not the 4 stroke motor gp bikes?

Because they're not sufficiently informed to make an observation. But due to personal fulfilment feel a need and therefore do so without considering the consequential impact of their observation on the perception of their intelligence by other forum members.

[mr bucketracer]

Because they're not sufficiently informed to make an observation. But due to personal fulfilment feel a need and therefore do so without considering the consequential impact of their observation on the perception of their intelligence to other forum members.are you into politics (-;

[steveyb]

KTM Moto3 engine uses radial valves.

[F5 Dave]

NSR500 uses power valves.
And reed valves
Control slicks use tyre valves.
Ahh I can do this all night.

[turns to self]I cannot do this all night.(Mongrels ref)

[husaberg]

. . .and the rules forbade it (hey that's probably the first time I've used that word). The FIM in their infinite wisdom, presumably as they were giving handies under the sheets to the Evil empire (H*nda) wanted to make sure 2 stroke performance increase was stifled as much as possible. Honda did actually test FI, but not direct injection.

Cost? you're kidding me? compared to now you could throw heaps at a 2 stroke & still not come close. Injection has shown decent fuel useage decreases.

Nah .....Honda not only tested they raced for a whole season......... a Fuel injected NSR500 it made no more power was more twitchy Doohan wasn't interested Itoh rode it it was trapped faster at Hokenheim (But Itoh was tiny and didn't have a bung leg so he could tuck in more)
As Dave said Honda pursued FI primarily to reduce fuel consumption and Emissions.
The Two strokes 500's were dropped (which was a shame) cause they lost there relevance.
No one was selling 500 two strokes but were selling heaps of 4 cylinder 4 strokes.........

[F5 Dave]

yeah but they didn't test direct injection direct injection did they? Well except in the EXP2 or whatever it was. But that was because rules didn't preclude it for desert racing. Some great engineers at Honda. Wasted due to their corporate policy of evil half time engines.

[husaberg]

yeah but they didn't test direct injection direct injection did they? Well except in the EXP2 or whatever it was. But that was because rules didn't preclude it for desert racing. Some great engineers at Honda. Wasted due to their corporate policy of evil half time engines.

I think the EXP way have been conventional injection well the version i seen was they ran it with Carbs as well.
The EXP was clever in its Trapping valve and Knock running and all the rest of the drama. I bet they did test Direct, but it gave less power so it wasn't worthwhile for the NSR..
Cagiva also raced the injection (or at least practiced) Fogerty fell off it in England and refused to race it as a wild card at least.
I had posted it on ESE ages ago along with the EXP2 and the Fuel injected NSR500 stuff. From memory Aprillia tried it but it was to twitchy.
(Someone said it was revisited successfully later and they remaped it to be less precise and it was fine then)
Cagivas interests were mainly in the packaging as it could allow narrower angles and short straighter inlets or even even disk valves.
Now Cagiva had some awesome engineers but were far too chaotic in there application unfortunately.

[husaberg]

Some stuff in the text from memory was wrong but what the hey........

[husaberg]

The Honda Stuff will be buried here when i can be arsed to find it oh its only the H20 stuff there...

[husaberg]

THe Fuel injected stuff will be somewhere here i guess

[husaberg]

Or here........

[F5 Dave]

. . .. I bet they did test Direct, but it gave less power so it wasn't worthwhile for the NSR..
. . ..

& I bet they didn't. I am 80% certain it wasn't permitted by the rules.

The FIM were set to stiffle further development of the 2 stroke as they were going through the throws of the bikes power outweighing the tyres. Hence the incremental increase of minimum weights & keeness to adopt highly toxic unleaded gas.

And also they were a bunch of short sighted fuckers who were in love with the old days of MV & Norton & decided if you can't beat em, - give the alternative a 2x capacity advantage.

No direct injection development so no advance in technology & road spinoff hence no appetite to race 2 strokes.

[husaberg]

But it could be here I can't be bothered looking....

[husaberg]

& I bet they didn't. I am 80% certain it wasn't permitted by the rules.

The FIM were set to stiffle further development of the 2 stroke as they were going through the throws of the bikes power outweighing the tyres. Hence the incremental increase of minimum weights & keeness to adopt highly toxic unleaded gas.

And also they were a bunch of short sighted fuckers who were in love with the old days of MV & Norton & decided if you can't beat em, - give the alternative a 2x capacity advantage.

No direct injection development so no advance in technology & road spinoff hence no appetite to race 2 strokes.

Dave Dave Dave.

A corporation the Size of Honda interested in Emissions didn't test direct injection...... Yeah Right:lol:

As you said earlier the Rules well Honda being the Devil well they were only for the other weren't they..........Honda could change the FIM mind at will couldn't they.......
The orbital project guy Ken posted some stuff on pitlane (same guy that makes the strike pistons) we could ask him i guess he might know.

Re the Capacity they gave em about 800cc vs 500 but it wasn't enough for a start........

BTW Bimota Vdue was always going to be direct injection and it was designed as a GP bike from a start so i guess you might be more than 20% wrong....

[slowpoke]

No direct injection development so no advance in technology & road spinoff hence no appetite to race 2 strokes.

What is this road spin-off you speak of? BMW make the best stock superbike and have never competed in MotoGP. Yamaha and Honda are the main players in MotoGP yet have the least technologically advanced bikes in the stock superbike class. The best/most advanced Jap bike is made by Kawasaki, who were the first to leave MotoGP in recent times.

Moral of the story seems to be if you want to make a decent Superbike either get out or stay out of MotoGP.

[F5 Dave]

Still a reasonable read for a friday afternoon. Dooeys 92 is still one of the best looking racebikes ever despite my hatred of ciggys.

[F5 Dave]

Dave Dave Dave.

A corporation the Size of Honda interested in Emissions didn't test direct injection...... Yeah Right:lol:

As you said earlier the Rules well Honda being the Devil well they were only for the other weren't they..........Honda could change the FIM mind at will couldn't they.......
The orbital project guy Ken posted some stuff on pitlane (same guy that makes the strike pistons) we could ask him i guess he might know.

Re the Capacity they gave em about 800cc vs 500 but it wasn't enough for a start........

BTW Bimota Vdue was always going to be direct injection and it was designed as a GP bike from a start so i guess you might be more than 20% wrong....

Actually I thought I had read that was one of the reasons Bimota flagged development of a GP bike because DI wasn't allowed.

Honda didn't test DI in GPs did they? - no they tested conventional in 2 races (obtaining fastest speed for quite some years).

Hoda weren't going out of thier way to advance 2 stroke technology were they? They wanted to race 4 strokes, just they couldn't on equal terms (NR500 anyone?)

Capacity was 990 vs 500 at the start, 800 was some years later well after 2 strokes written out of the rules.

[mr bucketracer]

What is this road spin-off you speak of? BMW make the best stock superbike and have never competed in MotoGP. Yamaha and Honda are the main players in MotoGP yet have the least technologically advanced bikes in the stock superbike class. The best/most advanced Jap bike is made by Kawasaki, who were the first to leave MotoGP in recent times.

Moral of the story seems to be if you want to make a decent Superbike either get out or stay out of MotoGP.remember Kawasaki has only won one superbike championship , honda and yamaha only seem to think superbikes is a second rate chamionship now days

[F5 Dave]

What is this road spin-off you speak of? BMW make the best stock superbike and have never competed in MotoGP. Yamaha and Honda are the main players in MotoGP yet have the least technologically advanced bikes in the stock superbike class. The best/most advanced Jap bike is made by Kawasaki, who were the first to leave MotoGP in recent times.

Moral of the story seems to be if you want to make a decent Superbike either get out or stay out of MotoGP.
um. . .I struggle to see the relevance of your point. No really. You're talking entirely about diesils in a 2 stroke related thread.

I was of course talking about the development of the DI 2 stroke. If it was raced there would be development. Its a different technology, not a progression of a roadbike.

Spin off could have been DI NSR250 et all & potentially larger capacity bikes again once emissions could be reined in which was the stumbling block and why 2 strokes disappeared from the road in diminishing engine sizes. if allowable emmissions for a vehicle is x amount then a 125 spewing 10% out is half the amount of a twin 250.

[mr bucketracer]

Actually I thought I had read that was one of the reasons Bimota flagged development of a GP bike because DI wasn't allowed.

Honda didn't test DI in GPs did they? - no they tested conventional in 2 races (obtaining fastest speed for quite some years).

Hoda weren't going out of thier way to advance 2 stroke technology were they? They wanted to race 4 strokes, just they couldn't on equal terms (NR500 anyone?)

Capacity was 990 vs 500 at the start, 800 was some years later well after 2 strokes written out of the rules.2 strokes fire twice as much so only fair there twice the size ( face it 2 strokes don't last very long as road bike between rebuilds . so why push a dead duck . think there good as a good performance race bike . off road , road race . not for the road.. just what i think

[F5 Dave]

2 strokes fire twice as much so only fair there twice the size . . .
Why should you give an advantage to a design that is handicapped by an obvious design flaw? 500cc is 500cc. That is fair.

And they're finding as dirtbikes the 2 strokes have a better reputation for reliability (although development has improved the latest 4 strokes so they last a bit longer than they did 10 yrs ago).

2 stroke roadbikes? Well there have been a heap of improvements that they would benefit from. Look at marine engines for reliability.

[mr bucketracer]

Why should you give an advantage to a design that is handicapped by an obvious design flaw? 500cc is 500cc. That is fair. bring a rotary out then

[F5 Dave]

yeah I agree, bring it on.

. . .Although swept volume debates will continue & the detractors do have their points.

[mr bucketracer]

yeah I agree, bring it on.

. . .Although swept volume debates will continue & the detractors do have their points.think is fires 6 + times per revolution somthing like that . anyway my mates 12a race car had 500hp - 250hp if a 600 , just think what top factorys could get from them ?? face it riders could not handle the power anyway

[mr bucketracer]

l can't think of a 2 stroke road bike from 1990 that benefited 500 gp technology, even years well before that

[F5 Dave]

The point was they were fighting emissions from well before the last hurrah and 500s had stagnated for many reasons, potential not being one of them

[mr bucketracer]

The point was they were fighting emissions from well before the last hurrah and 500s had stagnated for many reasons, potential not being one of themthats it . in a nut shell a 500 2 stroke uses the same amount of fuel as a 1000 four stroke and that because a 4 strokes fire half as much , lasts way longer , better controllable power, and still better on fuel , most bikes on the road are 4 strokes , most cars are 4 four strokes apart from the odd old dog . so can see why they did what they did.

[Drew]

thats it . in a nut shell a 500 2 stroke uses the same amount of fuel as a 1000 four stroke and that because a 4 strokes fire half as much , lasts way longer , better controllable power, and still better on fuel , most bikes on the road are 4 strokes , most cars are 4 four strokes apart from the odd old dog . so can see why they did what they did.
A forced induction, direct injected two stroke would have the same emissions as a four stroke. Capacity not withstanding of course.

The power could then be made controllable, and reliability just as good.

The system would, simply put, be more efficient all round.

[mr bucketracer]

A forced induction, direct injected two stroke would have the same emissions as a four stroke. Capacity not withstanding of course.

The power could then be made controllable, and reliability just as good.

The system would, simply put, be more efficient all round.so why did they not do it ?

[husaberg]

Actually I thought I had read that was one of the reasons Bimota flagged development of a GP bike because DI wasn't allowed.

Honda didn't test DI in GPs did they? - no they tested conventional in 2 races (obtaining fastest speed for quite some years).

Hoda weren't going out of thier way to advance 2 stroke technology were they? They wanted to race 4 strokes, just they couldn't on equal terms (NR500 anyone?)

Capacity was 990 vs 500 at the start, 800 was some years later well after 2 strokes written out of the rules.


No they (honda) didn't test DI in GP's as far a i know cause as i said and will say again it makes less power than indirect injection or it did then.
You said they never tested it maybe other than the EXP...... (which is obviously incorrect) i disagreed and was totally correct.
The fact that Bimota developed the DI for GP proves me more right unless they never bothered to read the rules..........
Honda were out to advance 2 stroke technology (when it suited them) Case reed for instance was on the RC125 years before Suzi...
Atac Herp RC valves water injection, fuel injection etc.
The EXP was a total 2 stroke technology showboat... (a corporate wank session)it was its only reason for existence....
Honda gave up on the NR then built the NS500 and were hugely successful building something different. reed 3 vs disk 4 but from memory with the NR Spencer did put it on pole at its last outing and won a race on it.Think it was non GP though.
The NR was also a show off of what they could build look at the rads the Forks the Carbon fibre.......


Re you saying it only had 2 outings on the duel injected NSR500 Itoh raced it for a season 93 (the article mentions he only did 2 races in 94) bar a couple of rides on Doohans bike when he was injured (Itohs best results were on a Doohans Carb bike though)

Remember that Yamaha killed the open MX with their want to build a Foul stroke...... People brought them in droves other manufacturers followed suit.

[husaberg]

so why did they not do it ?

Forced induction was only allowed half the capacity......
Honda did build a 250 turbo 4 stroke for Spencer to race in the 500 class that made incredible power. Not sure if it was actually raced but it was built...
Someone mentioned the Power of a 12a i say BS...... unless it was on funny fuel and blown........
The FIM rates rotary as 2x the swept.
Norton was effectively a 1100 racing against 750's cause they bent the rues in Blighty(to suit the Norton)
It still was pretty as was the 92 Honda.

[slowpoke]

um. . .I struggle to see the relevance of your point. No really. You're talking entirely about diesils in a 2 stroke related thread.

My bad, I thought you mentioned road spin off's, and MotoGP.......oh wait, you did. My point was that what we see in MotoGP does not automatically translate to the road and that road bikes can and have developed quite well without MotoGP. Same would apply for any 2T tech in your alternate reality if you stopped to think about it.

I was of course talking about the development of the DI 2 stroke. If it was raced there would be development. Its a different technology, not a progression of a roadbike.

Spin off could have been DI NSR250 et all & potentially larger capacity bikes again once emissions could be reined in which was the stumbling block and why 2 strokes disappeared from the road in diminishing engine sizes. if allowable emmissions for a vehicle is x amount then a 125 spewing 10% out is half the amount of a twin 250.

DI is all well and good in theory but it isn't the magic bullet for 2T's, have you thought about the effect of fitting catalytic converters to a 2T? DI alone isn't going to be enough to get them anywhere near increasingly stringent emissions testing regimes. And with 2T's extremely exhaust sensitive it ain't gonna be easy....imagine having to package 4 x cat's on an RZ/RG500.

[Drew]

so why did they not do it ?
Dunno. It's worked for ages in diesel applications.

Forced induction is frowned apon in racing, outside of rally for some reason.

[Drew]

DI is all well and good in theory but it isn't the magic bullet for 2T's, have you thought about the effect of fitting catalytic converters to a 2T? DI alone isn't going to be enough to get them anywhere near increasingly stringent emissions testing regimes. And with 2T's extremely exhaust sensitive it ain't gonna be easy....imagine having to package 4 x cat's on an RZ/RG500.That's why I said forced induction. Control the inlet and exhaust with valves, and the exhaust all of a sudden can be just like that on a four stroke.

[husaberg]

That's why I said forced induction. Control the inlet and exhaust with valves, and the exhaust all of a sudden can be just like that on a four stroke.

Go back and read Honda has done it with a Converted 4 stoke already......
Click on the arrow Drew.

Some stuff in the text from memory was wrong but what the hey........

I hate trying to read the articles like that. Does nothing good for my eyes.
then click and click again until the plus with the magnifying glass appears then click again they will blow up huge bigger than full screen about 4x full screen.

Lastly this is how cheap the 500's were to run until they got "lifed" out by the increased output Honda made Yam go to later.

See above and below for the cost of running the Yamaha latter on. Until they were made available by Yama at Kenny request ya were either a works rider or had an old old RS500 and finished a lot of laps down.........

[Drew]

Go back and read Honda has done it with a Converted 4 stoke already......I hate trying to read the articles like that. Does nothing good for my eyes.

[husaberg]

Last of the Yamaha privateer stuff has the costs of running etc.

[Dave-]

Couple of Journal articles and thesis papers I just pulled up:

Development of a novel uniflow-scavenged two-stroke gasoline direct injected engine
Thermodynamic analysis of supercharged fuel-injected two-stroke cycle engines
Direct injection of hydrogen, oxygen and water in a novel two stroke engine <-- fucking cool
Exhaust emissions of low level blend alcohol fuels from two-stroke and four-stroke marine engines
Advanced modern low-emission two-stroke cycle engines
Study on manifold injection of LPG in two stroke SI engine.

Here's a couple you guys should be able to view:

Control of Exhaust Emissions from Copper Coated Gasohol Run Two Stroke Spark Ignition Engine with Catalytic Converter
http://www.ccsenet.org/journal/index.php/mer/article/view/12104

Fuel Injection Pressure Effect on Performance of Direct Injection Diesel Engines Based on Experiment
http://www.doaj.org/doaj?func=openurl&genre=article&issn=15469239&date=2008&volume=5&issue=3&spage=197

Put down those poppy magazine articles and read something with a bit of substance. I'd crack through all eight if I didn't already have 20 ECU and data acquisition papers to read through....

edit: Fuckin' hell the English in that 2nd one is a bit wobbly.

[husaberg]

Couple of Journal articles and thesis papers I just pulled up:

Development of a novel uniflow-scavenged two-stroke gasoline direct injected engine
Thermodynamic analysis of supercharged fuel-injected two-stroke cycle engines
Direct injection of hydrogen, oxygen and water in a novel two stroke engine <-- fucking cool
Exhaust emissions of low level blend alcohol fuels from two-stroke and four-stroke marine engines
Advanced modern low-emission two-stroke cycle engines
Study on manifold injection of LPG in two stroke SI engine.

Here's a couple you guys should be able to view:

Control of Exhaust Emissions from Copper Coated Gasohol Run Two Stroke Spark Ignition Engine with Catalytic Converter
http://www.ccsenet.org/journal/index.php/mer/article/view/12104

Fuel Injection Pressure Effect on Performance of Direct Injection Diesel Engines Based on Experiment
http://www.doaj.org/doaj?func=openurl&genre=article&issn=15469239&date=2008&volume=5&issue=3&spage=197

Put down those poppy magazine articles and read something with a bit of substance. I'd crack through all eight if I didn't already have 20 ECU and data acquisition papers to read through....

edit: Fuckin' hell the English in that 2nd one is a bit wobbly.
Err i haven't posted the SAE articles as i, well won't..........

[mr bucketracer]

i like all racing . i don't care if 2 stroke or 4 . as long as engine size is done fairly ! to race them together

[Dave-]

Err i haven't posted the SAE articles as i, well won't..........

ok you win.

[husaberg]

Most of the stuff i posted wasn't that pop culture yes it was dummed down for the masses but as Dave_ has said, there is plenty of info out there.
What i was trying to show was injected 2 strokes were about in gp500's.Honda were doing lots 2 stroke research

I don't think direct injection can compete HP wise with injection or carbs for direct HP. but it can make emissions tolerable with decent HP.
Fletner is doing some clever stuff with some basic car components and getting great results.

Shit even Honda said indirect injection gave them no more power just 5-10% better fuel consumption.

Anyway here is some stuff.http://engineringcorner.blogspot.co.nz/2011/09/next-generation-2-stroke-engine.html





Hoda weren't going out of thier way to advance 2 stroke technology were they?
no only into 4 strokes..........


http://www.cycleworld.com/2012/08/13/two-stroke-resurrection/

In addition to direct fuel injection, there are other technologies that can help. Two decades ago, Honda introduced a 250cc, two-stroke motorcycle engine for a Japanese-market-only dual-purpose bike that utilized “Activated Radical Combustion.” This is a technology that has since been well-studied by the automotive industry and is more commonly known as HCCI (Homogenous Charge Compression Ignition), a combustion process that requires no spark but uses gasoline rather than diesel fuel. In Honda’s 250, HCCI combustion was maintained from about eight to 50 percent load, with conventional spark ignition used at both the high and low end of the engine load range. The benefit was far more stable combustion (no six- or eight-cycling) when HCCI was operating, lower emissions and—according to those who rode it—a two-stroke that felt as if it had the smooth power of a four-stroke. Honda’s patents have since expired.


http://www.crm250.com/site_images/crm/crm250ar.jpgCRM250 AR 1996 - 1999 And this is where it all stopped. Honda like all manufacturers were under increasing pressure from the USA and it's own country to clean up it's act and this is the first and only production bike that used Honda's development "Active Radical System". The "Active Radical System" or AR as it was known was a clever way to reduce emmisions from the unfreindly 2 stroke engine while giving more low down grunt at the same time. To ride a AR for the first time is quite odd. On the over-run it feels more like a 4 stroke engine and almost feels like the ignition has been cut, yet as soon as the throttle is opened up it kicks straight back into life. The AR models are very different not only in the engine area, but also the ignition and carburation, And features many electronic pickups and sensors to give the maximum burn with maximum efficiency. Dont let the style fool you with a Mk3 as the frames and motor are not interchangeable. Regarded by many as the Ultimate CRM250.
Prices are quite high for this model, and older well used bikes go for around £1400+ while the latest low mileage bikes are still changing hands for as much as £2200.http://www.crm250.com/history.asp
http://dwolsten.tripod.com/articles/jan97.html


http://i70.photobucket.com/albums/i92/Sabotage_street/Crm.jpgFor those who dont know, the CRM250AR was the production version of the EXP-2 Enduro prototype that used Active Radical Combustions to decrease emmissions.
The bike at low revs and low throttle openings closes and exhaust flap (hondas fancy word por PV) and introduces hot exhaust gases back into the cylinder to become thousands of tiny spark plugs (known as Active Radicals).
Therefore the Spark ignition is no longer required, the engine 'diesels' as it undergoes controlled detonation combustion.
When Undergoing AR combustion the engine purrs steadily without the expecting 'ring-ding-ding' unsteady combustion cycles common in two strokes. its almost akin to a four stroke.
Crank the throttle open and the engine comes to live with potency close to a CR250 honda.
Some EXP stuff
http://www.motorcycle.com/manufacturer/honda/quick-take-honda-exp2-15170.html

[husaberg]

This is some stuff i just found on a troll.

DI may have been banned although i think it was only indirectly banned (no fuel injection pressure above 10 bar is the current rule)
Note Dave Honda didn't get their way with getting the FIM to allow them to race the 250 Turbo esp note the HP

[F5 Dave]

That was 1985. Things change.

+ also they were probably peeping over the fence at F1 & Turbo madness that was going on (or so I understand, I never followed cars).

[mhbarber]

Couple of Journal articles and thesis papers I just pulled up:

Development of a novel uniflow-scavenged two-stroke gasoline direct injected engine
Thermodynamic analysis of supercharged fuel-injected two-stroke cycle engines
Direct injection of hydrogen, oxygen and water in a novel two stroke engine <-- fucking cool
Exhaust emissions of low level blend alcohol fuels from two-stroke and four-stroke marine engines
Advanced modern low-emission two-stroke cycle engines
Study on manifold injection of LPG in two stroke SI engine.

Here's a couple you guys should be able to view:

Control of Exhaust Emissions from Copper Coated Gasohol Run Two Stroke Spark Ignition Engine with Catalytic Converter
http://www.ccsenet.org/journal/index.php/mer/article/view/12104

Fuel Injection Pressure Effect on Performance of Direct Injection Diesel Engines Based on Experiment
http://www.doaj.org/doaj?func=openurl&genre=article&issn=15469239&date=2008&volume=5&issue=3&spage=197

Put down those poppy magazine articles and read something with a bit of substance. I'd crack through all eight if I didn't already have 20 ECU and data acquisition papers to read through....

edit: Fuckin' hell the English in that 2nd one is a bit wobbly.

thank you; for being the only person to (half(ish)) answer my question.

[husaberg]

Never seen the question, but considering the gains Aprilia made per year for HP given and given fair formula for 2 stroke vs 4 stroke.
The 2 stroke almost always wins for Gp racing...........
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=261462&d=1333621581

[F5 Dave]

thank you; for being the only person to (half(ish)) answer my question.
How did that answer your question knobend?

how about Aprilia RS 125 54 hp. x4 but with only one gearbox loss.

but also with a better soundtrack than the diesels.

[Dave-]

How did that answer your question knobend?

how about Aprilia RS 125 54 hp. x4 but with only one gearbox loss.

but also with a better soundtrack than the diesels.

Clearly because my post was so insightful!

I'm gonna miss access to journals when I leave university :(

[F5 Dave]

I just cant imagine he read any of it & is pretending to be a smarty. He needs a smack. I'd give him one next time I see him, but I'd need a stool & there's never one handy:lol:

[dangerous]

How did that answer your question knobend?

how about Aprilia RS 125 54 hp. x4 but with only one gearbox loss.

but also with a better soundtrack than the diesels.

yeah na... but Dave, is that a single or twin crank RS and would you call it a radial or V single?



but I'd need a stool & there's never one handy:lol:well... do what a few cantabs did a couple a years back and dump ya stool in a bag, take it with ya till you see him...


or use a paper bag and set it alight at his door...

[F5 Dave]

Wrong kind of stool, but I like your thinking. Actually might be easier to get thru Aussie customs. Find THIS in your cavity search mate. I can make a new one.

[mhbarber]

& I bet they didn't. I am 80% certain it wasn't permitted by the rules.

The FIM were set to stiffle further development of the 2 stroke as they were going through the throws of the bikes power outweighing the tyres. Hence the incremental increase of minimum weights & keeness to adopt highly toxic unleaded gas.

And also they were a bunch of short sighted fuckers who were in love with the old days of MV & Norton & decided if you can't beat em, - give the alternative a 2x capacity advantage.

No direct injection development so no advance in technology & road spinoff hence no appetite to race 2 strokes.

never let facts get in the way of a good rant.
Honda are in the business of making money; the writing was on the wall with our beloved 2-strokes, so they - and the other manufacturers - touted the change to 4-strokes.

[husaberg]

never let facts get in the way of a good rant.
Honda are in the business of making money; the writing was on the wall with our beloved 2-strokes, so they - and the other manufacturers - touted the change to 4-strokes.


Funny enough the movement started in about 94-95 Cagiva had just left to build the F4 leaving only Yamaha Suzuki and Honda to play in the 500's.

The WSB at the time (Flamini) had Ducati Kawasaki Honda yamaha, with Aprilia Harley Davidson and Cagiva all expected to join.
Then (Dorna i think it was who ran it) GP introduced the 600's thunder bikes for a bit of entertainment.

At the time Superbikes were far more of a spectacle and were drawing big audiences and revenue, and getting bigger and bigger every year.
This was starting to affect the GP incomes purses.
With the WSB The racing was close even if the lap times were slower than the 250 gp bikes.
Racing for most spectators is actually about entertainment.
We are all bike nuts and forget that, well i do anyway.:msn-wink:


My last post i missed something else.

Please take the time to read it.
The same thing happened (with F1, same guy) "It's all about making it more Professional".......................:no:

add in the Pay TV money and so on...............price for admission goes up so on..........

Far to many noses at the throughs.

Added the BMS851/985 cause i like it, and there is F-all pics on it on the Web. Is it still at BMS Dave.

here is the Formula a couple of boffins hired by thr FIM came up with for 2 vs four stroke.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=275059&d=1356318463

seems pretty fair to me 360cc vs 500cc or 500cc 2t vs 694cc 4t shit give them 750cc i don't care

[eelracing]

never let facts get in the way of a good rant.
Honda are in the business of making money;

Aye that is true,but the true rot set in when Dorna gave the manufacturers association the free agenda to set their own technical regulations.With the promise from said manufacturers that they would guarantee enough works and customer bikes.You can see how well that's worked out eh.

Every man and his dog knew costs would skyrocket and eventually only the manufacturer with the most resources would prevail.
Honda must be laughing all the way to the bank.

[husaberg]

Aye that is true,but the true rot set in when Dorna gave the manufacturers association the free agenda to set their own technical regulations.With the promise from said manufacturers that they would guarantee enough works and customer bikes.You can see how well that's worked out eh.

Every man and his dog knew costs would skyrocket and eventually only the manufacturer with the most resources would prevail.
Honda must be laughing all the way to the bank.

I agree with a lot of that but not the Honda making money out of Motogp i doubt it even at $250 for a gudgeon pin or what ever it was.
Manufacturers race for advertising and prestige not for money. esp Honda

[F5 Dave]

Far to many noses at the throughs.

Added the BMS851/985 cause i like it, and there is F-all pics on it on the Web. Is it still at BMS Dave.

here is the Formula a couple of boffins hired by thr FIM came up with for 2 vs four stroke.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=275059&d=1356318463

seems pretty fair to me 360cc vs 500cc or 500cc 2t vs 694cc 4t shit give them 750cc i don't care
BMS hasn't existed in its original form for over a decade. Dallas sold out to some guy in Upper Hutt, but I've never been there. I always remember a mate Chris who used to work there (wgtn) describing the then new 851 as a crashed helicopter as it's what it looked like unclothed, guess the FI gubbins made it more complex than the Pantahs by 2.

[eelracing]

Manufacturers race for advertising and prestige not for money. esp Honda

You miss my point,so let me clarify.
Advertising and prestige is money in the bank for a manufacturer...look at Ferrari in F1 and Ducati in Superbikes,both factories have built their reputation on racing success and with it comes sales.

Honda knows this and Yamaha too,but to put them in charge of the GP regs is like putting beneficiaries in charge of social welfare or cops in charge of donut shops.

I don't blame Dorna for doing this as they are money-men and longterm thinking is not in their interest.But the factories sold them a lie and the motorcycling press were creaming themselves over the thought of GP reps for the road.
Like I said,Honda are still laughing all the way to the bank.

[F5 Dave]

I still don't see why 2 strokes are any less relevant to road bikes as F1 is to cars. In fact F1 is totally alien to road cars.

[Mental Trousers]

I still don't see why 2 strokes are any less relevant to road bikes as F1 is to cars. In fact F1 is totally alien to road cars.

The number of 2 stroke scooters sold world wide you'd think 2 strokes are very relevant. But it seems those that influence the rules of GP racing aren't interested.

[eelracing]

I still don't see why 2 strokes are any less relevant to road bikes as F1 is to cars. In fact F1 is totally alien to road cars.

Exactly Dave and was a big part of Honda selling the myth to Dorna.
Afterall the two stroke era gave us radial tyres,decent frames and suspension,powervalves and by association exup exhaust valves that all manufacturers adopted,radial braking and big bang crank timing...I could go on.

The modern four stroke era has given us...um...er...5 valve heads are all shit...um...er 990's are to dangerous...um...er 800's are to boring...um...er oh yeah electronic control to take the guess work out of riding skills.

[tail_end_charlie]

Afterall the two stroke era gave us radial tyres,decent frames and suspension,powervalves and by association exup exhaust valves that all manufacturers adopted,radial braking and big bang crank timing...I could go on.

The modern four stroke era has given us...um...er...5 valve heads are all shit...um...er 990's are to dangerous...um...er 800's are to boring...um...er oh yeah electronic control to take the guess work out of riding skills.

Oh come on now, your comparing, what 50 years of GP racing 2 strokes to 10 years GP racing 4 strokes, hardly fair. I would sure as hell hope that they came up with a lot more advancments during the 2-stroke era considering that they had about 5x the development period. And if your trying to argue that there haven't been any frame, suspension, brake or tyre advances in the last 10 years, then you really need to get your head out of your 2-stroke ass.

Everything advances over time, if you don't keep up, you'll get left behind. Sorry, but the "glory days" of 2-stroke racing are in the past, get over it. Get excited about something new......

[eelracing]

And if your trying to argue that there haven't been any frame, suspension, brake or tyre advances in the last 10 years, then you really need to get your head out of your 2-stroke ass.

Comprehension is not your strong point is it son.

Those advancements would of come with the two stroke to you know.
The last ten years have just been refinements on what we already had with the two stroke era.

Try and remember that the argument from the manufacturers to Dorna (and to the world) to go fourstroke was sold as being more relevant to consumers.
Afterall how many V5/4 Honda race reps have you seen in your neck of the woods.I know Yamaha R1's are being sold on a crossplane crank but they're hardly flying out of showroom floors.

[tail_end_charlie]

Comprehension is not your strong point is it son.

Those advancements would of come with the two stroke to you know.

So are you saying they wouldn't have come along if there wasn't 2-strokes racing in GP's? Its all the same arguement, you are always going to get development on what is there. Boil it all down and your still working with a internal combustion engine (2-stroke or 4-stroke) that runs at somewhere between 20-30% efficiency.


The last ten years have just been refinements on what we already had with the two stroke era.

Ok, so lets say, pneumatic valves, slipper clutches (or electronic engine braking), multiple engine mapping accessable on the fly, ect ect. Yeah, a lot of electronics there, but lets be honest, thats the way the world is going. (And yes, I am one of that generation who has never bought a newspaper.)



Try and remember that the argument from the manufacturers to Dorna (and to the world) to go fourstroke was sold as being more relevant to consumers.
Afterall how many V5/4 Honda race reps have you seen in your neck of the woods.I know Yamaha R1's are being sold on a crossplane crank but they're hardly flying out of showroom floors.

Probably about as many as large bore (greater than 125cc) 2-stroke engines that have been sold recently...........actually, probably less. (Talking road bikes specifically, not off-road)
Even when 2-strokes were the king of GP racing, what was the ratio of 2-strokes vs. 4-strokes that were available to the public? I've been to a couple of classic bike show and swap meets, and the majority of bikes I see are 4-strokes. So it seems that the argument that the MSMA made for 4-strokes being more relevant to the consumer is correct........

[eelracing]

So are you saying they wouldn't have come along if there wasn't 2-strokes racing in GP's? Its all the same arguement, you are always going to get development on what is there. Boil it all down and your still working with a internal combustion engine (2-stroke or 4-stroke) that runs at somewhere between 20-30% efficiency.

Boil it all down and cc for cc a two stroke will waste a fourstroke...fact.

Ok, so lets say, pneumatic valves, slipper clutches (or electronic engine braking), multiple engine mapping accessable on the fly, ect ect. Yeah, a lot of electronics there, but lets be honest, thats the way the world is going. (And yes, I am one of that generation who has never bought a newspaper.)

Your world=extra weight,extra complexity and extra expense...proven fact if the last ten years has meant anything.


Probably about as many as large bore (greater than 125cc) 2-stroke engines that have been sold recently...........actually, probably less. (Talking road bikes specifically, not off-road)
Even when 2-strokes were the king of GP racing, what was the ratio of 2-strokes vs. 4-strokes that were available to the public? I've been to a couple of classic bike show and swap meets, and the majority of bikes I see are 4-strokes. So it seems that the argument that the MSMA made for 4-strokes being more relevant to the consumer is correct........

Bottom line,GP racing used to be about going from point to point faster than the next guy.Now it's about selling product,be it roadbikes or TV packages.
Now go back to the top of page 6,make yourself a nice cup of tea and start reading again...then get back to me when you've got a clue.

[F5 Dave]

. . . So it seems that the argument that the MSMA made for 4-strokes being more relevant to the consumer is correct........
So as I drove to work (its ok I had some bike parts in the van) I didn't see any open wheel driver exposed cars revving to 20,000 (or whatever tehy do I care not about car racing).

[F5 Dave]

. . . (And yes, I am one of that generation who has never bought a newspaper.).......
So that's who's stealling them. You probably have it away with me milk money too (its hard to buy tokens these days, mind you the milkman seems to have skipped us. . .- well for quite some time now. I'll send him a fax).

[Flettner]

APART from electronics, as these can be used on both 2 and 4 stroke, what has the fourstroke bought us development wise that's that much different than say the 1960's? Still four valve ( poppets ), still twin over head cam, still require many revs to make power ( BMEP is still much the same, just at a higher RPM ). Parts are lighter, a little less internal friction ( special coatings ). Not much excitement there!
Twostroke development was just getting started but the rules soon took care of that!
I think perhaps the " manufactures" didn't like the idea of modifying your twostroke with just a die grinder and a few clues. Fourstroke's are far more profitable to hot up with all that stuff, cams, valves, springs, pistons, etc, etc. The more you spend, the shorter the fuse.
The only fourstroke I have in my shed is sitting there waiting for it's 50hr piston change and I just can't get excited about it! I'd rather ride my "dirty old twostroke", way more fun.

[husaberg]

BMS hasn't existed in its original form for over a decade. Dallas sold out to some guy in Upper Hutt, but I've never been there. I always remember a mate Chris who used to work there (wgtn) describing the then new 851 as a crashed helicopter as it's what it looked like unclothed, guess the FI gubbins made it more complex than the Pantahs by 2.

Yeah i guess people move on and grow old plus all the fun probably went out of the sponsoring after Robert died as well.
Dallas used run an impressive stable of bikes. The 851 were brick like beneath the fairings, everything crammed on top of each other, Pasos were pretty damn ugly without the fairing as well.
I guess even the Italians don't see any need to make it pretty if no one ever sees it. i think it was Bordis first baby.
http://farm8.staticflickr.com/7027/6467151047_8f3d206ac0.jpg

[F5 Dave]

The following is conjecture, I do not know the guy:

I think more he'd realised he'd created a white elephant that virtually no one could afford to buy but foresaw the market tanking. Was pretty much the biggest bikeshop in the country revenue-wise I understand (you wouldn't think so) & sold mail order to all around the globe, buying up all sorts of NOS.

It takes a smart businessman to build an empire, but a smarter one to know when the market is changing & skedaddle. Internet was the big unknown I guess.

[Mental Trousers]

So are you saying they wouldn't have come along if there wasn't 2-strokes racing in GP's? Its all the same arguement, you are always going to get development on what is there. Boil it all down and your still working with a internal combustion engine (2-stroke or 4-stroke) that runs at somewhere between 20-30% efficiency.

Boil it all down and cc for cc a two stroke will waste a fourstroke...fact.

Problem is these days it's all about extracting as much as possible from a given amount of fuel not a given engine size. Four strokes are quite a way ahead in that regard unless you move to Direct Injection Two Strokes, then they're pretty much even.



Ok, so lets say, pneumatic valves, slipper clutches (or electronic engine braking), multiple engine mapping accessable on the fly, ect ect. Yeah, a lot of electronics there, but lets be honest, thats the way the world is going. (And yes, I am one of that generation who has never bought a newspaper.)

Your world=extra weight,extra complexity and extra expense...proven fact if the last ten years has meant anything.

Interestingly if you look at consumer transport in general the amount of shit that gets lumped onto a vehicle design in the name of efficiency, features, driveability, safety and comfort negates any weight advantage the two stroke has. If it's not going on the road the manufacturers aren't going to develop it on the race track (there are noteable exceptions like pneumatic valves etc and I'm not sure how they justify developing those).

[mr bucketracer]

APART from electronics, as these can be used on both 2 and 4 stroke, what has the fourstroke bought us development wise that's that much different than say the 1960's? Still four valve ( poppets ), still twin over head cam, still require many revs to make power ( BMEP is still much the same, just at a higher RPM ). Parts are lighter, a little less internal friction ( special coatings ). Not much excitement there!
Twostroke development was just getting started but the rules soon took care of that!
I think perhaps the " manufactures" didn't like the idea of modifying your twostroke with just a die grinder and a few clues. Fourstroke's are far more profitable to hot up with all that stuff, cams, valves, springs, pistons, etc, etc. The more you spend, the shorter the fuse.
The only fourstroke I have in my shed is sitting there waiting for it's 50hr piston change and I just can't get excited about it! I'd rather ride my "dirty old twostroke", way more fun.at the end of the day most bikes on the road are 4 strokes, guys that liked 4 strokes did not get to see gp 4 stroke racing for years when 2 strokes took over , injection was hardly out , traction control , running engines backwards ,making engines last longer , fuel tank sizes . l would of liked to see them race together .. maybe best was to limet fuel and run any size engine because thats what its about fuel aconomy and also how long engines last well thats what i think

[Flettner]

Problem is these days it's all about extracting as much as possible from a given amount of fuel not a given engine size. Four strokes are quite a way ahead in that regard unless you move to Direct Injection Two Strokes, then they're pretty much even.

Are you sure about that? Where do you get your facts? Twostroke has a lot less crap to turn over, I think you will find Rotax DI twostroke snow engines have been shown to be better in every way than the fourstrokes they compete with, including emissions and fuel economy, that's still just a loop scavenge engine.
Also indirect injection ( rear transfer port ) has been shown to burn approx 20% less fuel than a standard twostroke under the same riding conditions, same top end power. Dyno tested.
Twostroke's looking pretty good:yes:

[tail_end_charlie]

So are you saying they wouldn't have come along if there wasn't 2-strokes racing in GP's? Its all the same arguement, you are always going to get development on what is there. Boil it all down and your still working with a internal combustion engine (2-stroke or 4-stroke) that runs at somewhere between 20-30% efficiency.


Boil it all down and cc for cc a two stroke will waste a fourstroke...fact

Correct, not arguing that point. Any dummy should know that a 2-stroke has a better thermodynamic efficiency then a 4-stroke, the big drawback being that they are not as clean burning. (and yes that is relevant in today's world, sorry) Your original post below.....

Afterall the two stroke era gave us radial tyres,decent frames and suspension,powervalves and by association exup exhaust valves that all manufacturers adopted,radial braking and big bang crank timing...I could go on.
The modern four stroke era has given us...um...er...5 valve heads are all shit...um...er 990's are to dangerous...um...er 800's are to boring...um...er oh yeah electronic control to take the guess work out of riding skills.
..................are you trying to say that the only reason that we had any developments in motorcycle technology is due entirely to 2-strokes racing in GP's? If the 2-strokes had never come around and they raced 4-strokes do you think that there wouldn't have been any advances in frame technology, radial tyres, suspension, radial brakes, ect?


Ok, so lets say, pneumatic valves, slipper clutches (or electronic engine braking), multiple engine mapping accessible on the fly, ect ect. Yeah, a lot of electronics there, but lets be honest, thats the way the world is going. (And yes, I am one of that generation who has never bought a newspaper.)


Your world=extra weight,extra complexity and extra expense...proven fact if the last ten years has meant anything.

And I would imagine that the generation before you would say the same thing about alternators vs generators, magnetos and points ignition systems vs electronic ignition, carbs vs FI, and on and on and on. Anyone who sticks their head in the sand to ignore advances in technology will get left behind. The more you use technology, the more it gets refined, the more robust it becomes. Sure the modern cell phone is a lot more complicated than an old radiotelephone, but which do you use?



Probably about as many as large bore (greater than 125cc) 2-stroke engines that have been sold recently...........actually, probably less. (Talking road bikes specifically, not off-road)
Even when 2-strokes were the king of GP racing, what was the ratio of 2-strokes vs. 4-strokes that were available to the public? I've been to a couple of classic bike show and swap meets, and the majority of bikes I see are 4-strokes. So it seems that the argument that the MSMA made for 4-strokes being more relevant to the consumer is correct........

^^I'm sorry, I must have missed you response where you told me just how much more relevant a twin, counter-rotating crank V-4 2-stroke engines were to the run of the mill production bike that mere mortals could buy from their local dealer????


Bottom line,GP racing used to be about going from point to point faster than the next guy.Now it's about selling product,be it roadbikes or TV packages.

Yeah, because AJS, Aprilla, Derbi, Ducati, Garelli, Gilera, Kreidler, Harley Davidson, Honda, Kawasaki, Mondial, Moto Guzi, MV Augusta, Norton, Suzuki and Yamaha never got into racing in the first place to sell bikes. Right? I hardly think so. It's always has been, and always will be, about who goes fastest on WHICH bike.

Now go back to the top of page 6,make yourself a nice cup of tea and start reading again...then get back to me when you've got a clue.
Your turn................:bleh:

[tail_end_charlie]

So as I drove to work (its ok I had some bike parts in the van) I didn't see any open wheel driver exposed cars revving to 20,000 (or whatever tehy do I care not about car racing).

Good point, and I hear next year they are going to turbocharged V6's, and we also never see any turbo-charged V6 powered cars out there either....................oh wait.

I think you will find more similarities between the fundamental design principles (engine, EMS, braking, suspension, ect ect) of a F1 car and a modern sports car then you would between a 90's GP bike (2-stroke) and a 90's sports bike (majority of which were 4-stroke).

And I'm glad you brought up cars, because if 2-stroke engines are all so much better than 4-stroke, then why didn't we ever see 2-stroke cars everywhere???? Are ya'll trying to say that Honda has so much influence over the world that they decided they didn't like getting beaten in GP racing, so they made sure every automotive industry in the world went to 4-stroke???? Cause that would be one hell of a conspiracy theory. That may just be enough to get you committed..........

[tail_end_charlie]

So that's who's stealling them. You probably have it away with me milk money too (its hard to buy tokens these days, mind you the milkman seems to have skipped us. . .- well for quite some time now. I'll send him a fax).

A fax!?!?! Holy shit! :gob: You're using modern technology!!!!! I would have thought you were still using a fire and a blanket to throw up smoke signals............:innocent:

[husaberg]

I think you will find more similarities between the fundamental design principles (engine, EMS, braking, suspension, ect ect) of a F1 car and a modern sports car then you would between a 90's GP bike (2-stroke) and a 90's sports bike (majority of which were 4-stroke).


Seen a NSR250 Honda and a Early 90s RS250?
Or a RGV250 and a RGV250 GP bike
The Yamaha's 250's were even closer.....

[tail_end_charlie]

Seen a NSR250 Honda and a Early 90s RS250?
Or a RGV250 and a RGV250 GP bike
The Yamaha's 250's were even closer.....

What were the numbers though? Lets say a comparison of production numbers during the 90's between 2-stroke bikes and 4-stroke bikes? I know that there were production GP replica's put out there, but what were their numbers?

(I may have shot myself in the foot there, cause I don't actually know........)

And for the record, I've never seen many of the 2-stroke bikes up close...................they'd all been blown up by the time I got into bikes..............................:whistle:

[Flettner]

In reality it's a great situation, no twostroke road bikes available to choose from. It makes for a good market for smaller manufactures ( specialist ) to produce perhaps two and three cylinder road going bikes, fuel injected. Light and fast and most of all, DIFFERENT! You might find there is more interest out there than you might think.

[Mental Trousers]

Are you sure about that? Where do you get your facts? Twostroke has a lot less crap to turn over, I think you will find Rotax DI twostroke snow engines have been shown to be better in every way than the fourstrokes they compete with, including emissions and fuel economy, that's still just a loop scavenge engine.
Also indirect injection ( rear transfer port ) has been shown to burn approx 20% less fuel than a standard twostroke under the same riding conditions, same top end power. Dyno tested.
Twostroke's looking pretty good:yes:

You'd have to point me to the stats that compare the Rotax 800R E-TEC to a four stroke of comparable performance in a similar application cos I haven't been able to find any. It'd have to be something like a 750-850cc four cylinder otherwise you're not comparing similar specs, ie similar power outputs to see the difference in fuel consumption etc.

[husaberg]

What were the numbers though? Lets say a comparison of production numbers during the 90's between 2-stroke bikes and 4-stroke bikes? I know that there were production GP replica's put out there, but what were their numbers?

(I may have shot myself in the foot there, cause I don't actually know........)



You did, as they were huge sellers in their market segment......sports 250's.
I would also hazard a guess there survival rate is actually higher than their expensive to fix 4 stroke brethren as well.

AS for 4T vs 2T sales pointless...... ever wondered what the biggest selling bikes are in NZ......

[steveyb]

And I'm glad you brought up cars, because if 2-stroke engines are all so much better than 4-stroke, then why didn't we ever see 2-stroke cars everywhere???? .

Here ya go....

http://en.wikipedia.org/wiki/Suzuki_Fronte

My mates family had a 7S-SS10. Bloody neat it was.


Well, I guess they aren't quite everywhere......

[roogazza]

What were the numbers though? Lets say a comparison of production numbers during the 90's between 2-stroke bikes and 4-stroke bikes? I know that there were production GP replica's put out there, but what were their numbers?

(I may have shot myself in the foot there, cause I don't actually know........)

And for the record, I've never seen many of the 2-stroke bikes up close...................they'd all been blown up by the time I got into bikes..............................:whistle:

It seems you are one or two eras ahead of some of us ? I'm sure you would have loved ours.
I started in 1965 on a new 80cc TwoStroke Yamaha, never owned a 4T.
Graduated whole heap of 250s,350s,400s,500 lastly 750cc triple in 1972 ! All 2Ts.
4Ts from 85 onwards. 50 bikes!
Imagine what you'll be riding in your sixties ? or if ?

[F5 Dave]

Here ya go....

http://en.wikipedia.org/wiki/Suzuki_Fronte

My mates family had a 7S-SS10. Bloody neat it was.


Well, I guess they aren't quite everywhere......
Same model as a mates. Golly was it 30 years ago.
Reputed to be so small you could have driven it through the botanical gardens pathways in the small hours. Not that it ever happened of course:innocent:.

[tail_end_charlie]

It seems you are one or two eras ahead of some of us ? I'm sure you would have loved ours.
I started in 1965 on a new 80cc TwoStroke Yamaha, never owned a 4T.
Graduated whole heap of 250s,350s,400s,500 lastly 750cc triple in 1972 ! All 2Ts.
4Ts from 85 onwards. 50 bikes!
Imagine what you'll be riding in your sixties ? or if ?

Ha ha, yeah, I think there may be a few gens between us. :innocent:
Grew up in the States following Dad around to bike shows and swap meets and stuff, but it was almost all classic American or European 4-stroke stuff. Never had much if anything to do with 2-strokes, other than cursing chainsaws.

And granted, the 2-stroke era may have been great and all, but I get a bit pissed off when people talk about it as the end all and be all, and their ain't nothing good that has happened since they got rid of the smokers. Different perspectives........

[steveyb]

Same model as a mates. Golly was it 30 years ago.
Reputed to be so small you could have driven it through the botanical gardens pathways in the small hours. Not that it ever happened of course:innocent:.

Oh, no, never happened I am quite sure!

Yep, 30 years ago. Seems like yesterday.
Remember doing a couple of rebuilds on the engine after siezures!!!
But small enough to fit down a one lane road with a milk tanker already on the road!!!

Choice!

[roogazza]

Ha ha, yeah, I think there may be a few gens between us. :innocent:
Grew up in the States following Dad around to bike shows and swap meets and stuff, but it was almost all classic American or European 4-stroke stuff. Never had much if anything to do with 2-strokes, other than cursing chainsaws.

And granted, the 2-stroke era may have been great and all, but I get a bit pissed off when people talk about it as the end all and be all, and their ain't nothing good that has happened since they got rid of the smokers. Different perspectives........

My present bike a gsxr thou is an amazing thing, far better than I am. As I said in another thread," Riding it is like having sex with an Aerobics Instructor " !!!!!

[F5 Dave]

ok at the time but more brain damage than its worth? :oi-grr: Not going there again.

[Grumph]

Here ya go....

http://en.wikipedia.org/wiki/Suzuki_Fronte

My mates family had a 7S-SS10. Bloody neat it was.


Well, I guess they aren't quite everywhere......

We bought one of those shortly after getting married. $1800 new from manchester fiat in ChCh - and it got thrashed unmercifully....did the small ends once and the diff bearings twice - I could have the donk out in 35min...
At ruapuna testing bike one day and decided to try a few laps....65 seconds flat - but you had to throw it at the sweeper to keep it on the band in 3rd. Couple of weeks later at a combined car/bike day I asked a couple of Lotus Cortina owners what their times were...67 sec...maybe i should have raced it lol....Someone put a full TR750 motor in a fronte coupe for allcomers. It was seen once and disappeared. Reputedly, it kept spinning at the Ruapuna hairpin under brakes, not surprised.
Dave - remind me to show you a pic when you come down for the BoB - the young grumph,homebuilt TR3 and fronte - none of us aged well.

[quickbuck]

So as I drove to work (its ok I had some bike parts in the van) I didn't see any open wheel driver exposed cars revving to 20,000 (or whatever tehy do I care not about car racing).

There may have been one or two on the road that have a Kinetic Energy Recovery System in them though........
No DRS on cars yet, but many have Flappy Paddle Semi Auto Gearboxes....

Na, no F1 Technology ever makes it into cars...... ;)

[husaberg]

There may have been one or two on the road that have a Kinetic Energy Recovery System in them though........
No DRS on cars yet, but many have Flappy Paddle Semi Auto Gearboxes....

Na, no F1 Technology ever makes it into cars...... ;)

I think the flappy paddle was actually a kart innovation?

[quickbuck]

I think the flappy paddle was actually a kart innovation?

Could have been... but it was Ferrari that developed the 7 Speed Sequential Box for use in cars that the paddles operate.
Of course sequential boxes have been around for years.............. and Kart Gearbox motors typically seem to be Motorcycle engines.

[husaberg]

Could have been... but it was Ferrari that developed the 7 Speed Sequential Box for use in cars that the paddles operate.
Of course sequential boxes have been around for years.............. and Kart Gearbox motors typically seem to be Motorcycle engines.

I see you seen the irony of my last post lol.

This is some stuff i trawled up on the 90's Yams.
From memory the GP's were an hour i think.
I added some Honda and Doohan pics cause i felt like it.

[F5 Dave]

Imagine having to ballast your 4 cyl bike up to 130kg:blink:

[Crasherfromwayback]

Imagine having to ballast your 4 cyl bike up to 130kg:blink:

Think the limit was 118kg way back in the day wannit? Then maybe to 124...then 130?

[F5 Dave]

I couldn't be bothered researching it, but it was in the era of trying to reduce the speed & expense but yes they kept pushing the limit up. - real racebikes Brucie.


Hmm, quick Wiki: 160 kg now. Bloody buses.

[Crasherfromwayback]

I couldn't be bothered researching it, but it was in the era of trying to reduce the speed & expense but yes they kept pushing the limit up. - real racebikes Brucie.


Hmm, quick Wiki: 160 kg now. Bloody buses.

Yeah fucking lard buckets! Fast but.

[F5 Dave]

So's a Tokyo train.

[steveyb]

So's a Tokyo train.

Shinkansen