Wild Dog Adventure Riding

General => General Bike Related Banter => Topic started by: Mapog on April 16, 2020, 07:03:13 pm

Title: When would the Japs catch up with 2T, if ever?
Post by: Mapog on April 16, 2020, 07:03:13 pm
Looking at the 2T threads running, I cant help but to think how nonchalant they are regarding 2Ts. They all used to make good 2Ts, but they dont want/arent interested/ environmental laws keep them from doing?

Would they aver wake up? It seem as if they are lagging behind and have no intention of catching up.

KTM have nice fuel injection running and there are even new direct injection technology on the horizon.
 Yamaha, the Jap manufacturer that still make 2Ts, dont even have fuel injection yet?
When will they launch DI?
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: sidetrack on April 16, 2020, 07:07:48 pm
The YZ's did get new style plastics about two years ago ...
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 16, 2020, 07:12:16 pm
I suppose it is more due to the use different sports to promote their products.  I doubt if Honda or Suzuki would run a factory team at Ertzberg.  The hard enduro scene is the home of 2 strokes.

MX and enduro cross work well these days with 4t's.

Thoughts?
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: MonkeyNot on April 16, 2020, 07:12:29 pm
Looking at the 2T freds running, I cant help but to think how nonchalant they are regarding 2Ts. They all used to make good 2Ts, but they dont want/arent interested/ environmental laws keep them from doing?

Would they aver wake up? It seem as if they are lagging behind and have no intention of catching up.

KTM have nice fuel injection running and there are even new direct injection technology on the horizon.
 Yamaha, the Jap manufacturer that still make 2Ts, dont even have fuel injection yet?
When will they launch DI?
https://www.google.com/amp/s/www.dirtlegal.com/blog/2018/5/16/is-the-2-stroke-dirt-scene-dying%3fformat=amp

Good read regarding your post

Sent from my SM-N960F using Tapatalk

Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Welsh on April 16, 2020, 07:21:57 pm
The share price, the environment, the share price, nasty motorbikes tearing up the hiking trails, the share price etc etc priorities 🙄
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 16, 2020, 07:37:11 pm
A good read.

Back in 1999 when I bought my Aprilia Pegasso, there were rumors that Aprilia was working on a street legal 600cc 4 cylinder 2t.  I salivated.

If it ever was, emissions killed it I suppose.  But just imagine.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 16, 2020, 09:24:54 pm
23 years ago this year, Yamaha launched it's Fuel injected 2strokes on their outboard range.

But for Yamaha in their marine engines, TPI is old news, they have been on HPDI for many years, injecting the fuel into the cylinder AFTER the exhaust port has closed.

I also cannot understand why Yamaha is allowing the 2stroke motorcycle to lag.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Mapog on April 16, 2020, 09:32:48 pm
My thoughts as well.
They have, why not use it?
Dont want to overcomplicate things?
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 16, 2020, 09:52:40 pm
My thoughts as well.
They have, why not use it?
Dont want to overcomplicate things?

I believe that Yamaha's structure as a corporate works very differently to say KTM.

For KTM their motorcycle sales is everything, for Yamaha it is just a part of Yamaha corporation.

But if you look back at the DT-1, RD range, etc, then Yamaha is asleep on their porridge bowl right now.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 16, 2020, 10:03:40 pm
23 years ago this year, Yamaha launched it's Fuel injected 2strokes on their outboard range.

But for Yamaha in their marine engines, TPI is old news, they have been on HPDI for many years, injecting the fuel into the cylinder AFTER the exhaust port has closed.

I also cannot understand why Yamaha is allowing the 2stroke motorcycle to lag.
AFAIK large diesel 2 strokes still power large ships.  That must say something.  Where to fit a compressor on an enduro bike though  :pot:  No need for 2t oil then.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: BuRP on April 16, 2020, 10:18:59 pm
they have been on HPDI for many years, injecting the fuel into the cylinder AFTER the exhaust port has closed.

As fantastic as that is (and it really is because in a minutely short time they must get good mixing right, not by any means easy!) that still leaves the 2T's Achilles Heel .... unburnt oil in the exhaust gases.
And that will, almost has already, spelled its doom and disappearance because environmental laws get stricter and stricter.
The current crop of KTM's 300's are Euro 4 compliant, achieved without any catalyst or exhaust particulate filtering, nothing.... but Euro 4 compliant!
That is truly amazing, however also the pinnacle: Euro 5 won't be possible without tackling exhaust gas cleaning and/or filtering/treatment/why.
But, that is nigh on impossible because a Cat needs a relatively high (and constant) temperature to operate effectively, and the pressure waves within the resonant exhaust system - which is absolutely crucial for the performance of this type of engine! - cause temperatures to fluctuate due to high and low pressure areas... which unfortunately travel throughout the entire length of the exhaust system, hence with it the temperature fluctuations also.
In addition it is almost impossible, I think definitely practically, to 'treat' the exhaust gas without disturbing (read: diminishing) the resonant waves hence affecting the effective output of the engine.
Strokers are a dying breed kept alive in ICU by KTM only, never mind some odd little others, but how long this will be legally tolerated by the powers that be is anyone's guess.

Do I hate strokers?
Are you fu&^%g nuts?
LOVE them!  :thumleft:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 16, 2020, 10:35:31 pm
The YZ's did get new style plastics about two years ago ...

And that new plastics got a 15 year old unaltered design 3rd spot in last years' Roof. :biggrin:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: AfricaOffroad on April 17, 2020, 07:31:05 am
The KTM 300 is only Euro4 compliant when running a very different exhaust with lamda sensor closed loop fueling. They make about 10 hp in that configuration. Those pipes come in the crate and get thrown straight in the bin.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Rossdog on April 17, 2020, 07:42:33 am
A decade from now, the scenario may be different. Hydrogen powered 2 stroke prototypes are already being tested for MotoGP. Imagine if this technology filters down; we will have the best of both worlds, the thrill of a 2 stroke with no smelly pre-mix and blue clouds, the only emission being pure water.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 17, 2020, 07:54:47 am
A decade from now, the scenario may be different. Hydrogen powered 2 stroke prototypes are already being tested for MotoGP. Imagine if this technology filters down; we will have the best of both worlds, the thrill of a 2 stroke with no smelly pre-mix and blue clouds, the only emission being pure water.

A decade from now, the Dakar bikes will make their own water. :thumleft:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 17, 2020, 08:32:30 am
OK, let us look at history regarding this, and this is off the top of my head only, so no years, dates, etc.

The Japanese have always been strong, up to 2000, dominant, in motocross.  Yet enduro bikes have never been a Japanese strongpoint.

Yamaha had the late70's IT range, which was probably the best enduro range to come from Japan, and they had some success with them. Suzuki had the PE range of bikes, but big success evaded them.

Kawasaki's KDX range ran the longest, and built a loyal following because of their toughness.

The last  proper enduro bike was the KDX200, discontinued in 2006, by which time the KTM200 overshadowed it.

Today, only Yamaha offers a version of an enduro bike, and this machine, the YZ250X, is a factory-converted MX bike.

My point??

The Japanese have for some reason, never had their hearts into 2stroke enduro bikes, and I do not know whether this will ever change.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: TheBear on April 17, 2020, 09:01:15 am
OK, let us look at history regarding this, and this is off the top of my head only, so no years, dates, etc.

The Japanese have always been strong, up to 2000, dominant, in motocross.  Yet enduro bikes have never been a Japanese strongpoint.

Yamaha had the late70's IT range, which was probably the best enduro range to come from Japan, and they had some success with them. Suzuki had the PE range of bikes, but big success evaded them.

Kawasaki's KDX range ran the longest, and built a loyal following because of their toughness.

The last  proper enduro bike was the KDX200, discontinued in 2006, by which time the KTM200 overshadowed it.

Today, only Yamaha offers a version of an enduro bike, and this machine, the YZ250X, is a factory-converted MX bike.

My point??

The Japanese have for some reason, never had their hearts into 2stroke enduro bikes, and I do not know whether this will ever change.

Perhaps (and I have no idea, just guessing here) the Japanese always concentrated on road bikes.  Similar to KTM, until very recently concentrated on off-road bikes and the Europeans (excluding KTM) on bigger road bikes.  Each designed, build and marketed for a specific market and while the cash was rolling in, from that  market, didn't worry too much about expanding.  With globalisation and various other economic pressures markets changed and some made changes to their typical business plan.  KTM / Road Bikes, BMW / smaller bikes, etc.

Agreed Danie on Yamaha and a 2T engine.  If we look at their marine engines, they should be able to build a pretty nifty 2T bike engine.  I don't think they see a need.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Roxtar on April 17, 2020, 12:28:27 pm
The Japanese actually hate 2T imo…. they lead the way in MotoGP away from the 2T era with Honda being the main protagonist in this arena....
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 17, 2020, 12:50:58 pm
The Japanese actually hate 2T imo…. they lead the way in MotoGP away from the 2T era with Honda being the main protagonist in this arena....

When you are sold a 4stroke, instead of a 2stroke, you are also buying a lot of parts extra from the OEM. Afterwards your 4stroke is also bound to earn the OEM much more in maintenance and parts.

It gives the manufacturer license to sell you a 2stroke, and then go like; "Hey, you've got to also buy this camshaft, chain, tensioner, 4 valves, springs, seals, cotters and ugly sound along with the bike" :eek7:

One of the main drives behind the 4stroke rush, from an economical and business perspective.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Mapog on April 17, 2020, 02:56:17 pm
If Yamie could just put FI on their bikes.
Surely cant be that difficult?

Direct injection is the real difficult one to master on 2Ts?
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 17, 2020, 03:08:08 pm
Just referencing to marine 2t diesels again.  Air injection is where the revolution lies.  Imagine no transfer port, no 2t oil and fuel injection economy on a 2t performance scale.  Hell, throw in short skirt lightweight pistons with 12000rpm.  Even dream away those easy to damage expansion pipes that won't be needed anymore.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: BuRP on April 17, 2020, 03:11:14 pm
Direct injection is the real difficult one to master on 2Ts?

Yip, especially when high power (means high revolutions meaning excruciatingly little time!) is chased!
Bimota failed, KTM, due to their (Patented I believe?) TPI, gets it right now... but there's yyeeaarrss of development inbetween these two.
TPI injects fuel droplets into a high velocity gasflow, the best place to do this!
Yammie may do this directly into the closed-off cylinder of outboard engines but one has to use very high fuel pressures to attempt - attempt yes, success is not guaranteed - complete atomizing of the fuel... and likely they will try to attempt some gas-swirl in the cylinder (I don't know if they do but this would be beneficial) to ensure better mixing as well as evaporation of the fuel droplets - which still will be droplets, never mind how high-pressure you inject the fuel!
Difficult indeed, and such will complicate a 'simple' 2stroke engine quite a bit, ditto its price!
But, that still leaves the main advantage of this engine: high power for little weight >>>>> that's for bikes then, plus (but to a lesser degree) outboard engines, not at all for cars.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: BuRP on April 17, 2020, 03:12:38 pm
Hell, throw in short skirt lightweight pistons

 :lol8:
Lol lol lol!
No, you forget a few basics  :P

Here's a hint: a 2stroke's piston skirt has a minimum height of Stroke - Transfer Port Height  ;)
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: TheBear on April 17, 2020, 03:13:16 pm
The Japanese actually hate 2T imo…. they lead the way in MotoGP away from the 2T era with Honda being the main protagonist in this arena....

When you are sold a 4stroke, instead of a 2stroke, you are also buying a lot of parts extra from the OEM. Afterwards your 4stroke is also bound to earn the OEM much more in maintenance and parts.

It gives the manufacturer license to sell you a 2stroke, and then go like; "Hey, you've got to also buy this camshaft, chain, tensioner, 4 valves, springs, seals, cotters and ugly sound along with the bike" :eek7:

One of the main drives behind the 4stroke rush, from an economical and business perspective.

If true, they did not succeed much, making them so incredibly reliable.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 17, 2020, 03:17:30 pm
Hell, throw in short skirt lightweight pistons

 :lol8:
Lol lol lol!
No, you forget a few basics  :P

Here's a hint: a 2stroke's piston skirt has a minimum height of Stroke - Transfer Port Height  ;)
Very enlightening.  Care to elaborate?  We are talking of the possibilities, no?
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 17, 2020, 03:18:36 pm
Hell, throw in short skirt lightweight pistons

 :lol8:
Lol lol lol!
No, you forget a few basics  :P

Here's a hint: a 2stroke's piston skirt has a minimum height of Stroke - Transfer Port Height  ;)
Thank you for the edit.  Did you even read my post.  Any understanding of 2t diesel tech?
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 17, 2020, 03:20:26 pm
https://auto.howstuffworks.com/diesel-two-stroke1.htm @BuRP

Use a little imagination and think if the tech could be used in a small bike engine.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: BuRP on April 17, 2020, 03:23:24 pm
Even dream away those easy to damage expansion pipes that won't be needed anymore.

No, didn't even read this bit..... do you actually know how&why a 2stoke makes so much power?
The exhaust is a LARGE contributor, is is simply crucial for making power!
No, not on diesels, but their reciprocating mass (the crosshead, split conrods etc) rule out making high power relatively speaking (Hp/L), so let's stick to bike-2stokes here  ;)

Got a 2stoke plastic?
Take off the exhaust then run it!
It will run, but zero power!
And yes, loadsa noise, Plapp Plapp Palapp...  :P
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 17, 2020, 03:29:10 pm
Even dream away those easy to damage expansion pipes that won't be needed anymore.

No, didn't even read this bit..... do you actually know how&why a 2stoke makes so much power?
The exhaust is a LARGE contributor, is is simply crucial for making power!
No, not on diesels, but their reciprocating mass (the crosshead, split conrods etc) rule out making high power relatively speaking (Hp/L), so let's stick to bike-2stokes here  ;)

Got a 2stoke plastic?
Take off the exhaust then run it!
It will run, but zero power!
And yes, loadsa noise, Plapp Plapp Palapp...  :P
If you could do all the exhaust function mechanically the pipe would be unnecessary.  That said, I will bow out of this conversation.  I was hoping to find someone with imagination to bounce ideas with.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: BuRP on April 17, 2020, 03:33:13 pm
Any understanding of 2t diesel tech?

Yes - awesome for humongously sized engines, and totally irrelevant for small ones.
You do know that those things rev to what, 700 rpm max in ships?
Yeah, a fairly high efficiency, but VERY low power per litre  ;)

Google Ryger engine, a better idea I think....
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: katana on April 17, 2020, 03:41:48 pm
Any understanding of 2t diesel tech?

Yes - awesome for humongously sized engines, and totally irrelevant for small ones.
You do know that those things rev to what, 700 rpm max in ships?
Yeah, a fairly high efficiency, but VERY low power per litre  ;)

Google Ryger engine, a better idea I think....


Did I say build a ship size enduro bike?  Do you have any idea of the size and weight of a ship engine piston?   :imaposer:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 17, 2020, 04:54:50 pm
Itoh's 1993 Honda NSR500 had electronic fuel injection, but Honda reckoned that on a race bike it made too little difference to be worth the effort.

So, yes, the Japanese applied F.I. some 27 years before the Europeans.

The fact that all their 4strokes are F.I. tells me they are not interested in further enhancing the 2strokes.

Fuckin' Yamaha, they're the ones that got me hooked on 2strokes....... :thumleft:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Bill the Bong on April 17, 2020, 05:12:40 pm
Before somebody tells me as well that I have no imagination:  I see no need for FI in any form in a 2T.  The need only arose because the newer generation doesn't have a clue how to jet a 2T.  Or was not willing to spend 5 min to change a main jet when the season change.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 17, 2020, 05:26:21 pm
Before somebody tells me as well that I have no imagination:  I see no need for FI in any form in a 2T.  The need only arose because the newer generation doesn't have a clue how to jet a 2T.  Or was not willing to spend 5 min to change a main jet when the season change.

 :thumleft:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Welsh on April 17, 2020, 07:10:00 pm
Never mind 2 strokes, I don't see much new tech from the Japanese on bikes full stop, unless you are an electronic display worshiper?  :sip:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: BuRP on April 18, 2020, 09:59:16 am
Do you have any idea of the size and weight of a ship engine piston?

Yes - I've stood and sat on them whilst fixing their cracks.... with this stuff, watch the video clip:
https://www.metalockengineering.com/en/typical-repairs/metal-stitching/
Cast iron pistons yes, hence my remark of being a bit too heavy for a bike  :lol8:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Welsh on April 18, 2020, 10:04:12 am
Do you have any idea of the size and weight of a ship engine piston?

Yes - I've stood and sat on them whilst fixing their cracks.... with this stuff, watch the video clip:
https://www.metalockengineering.com/en/typical-repairs/metal-stitching/
Cast iron pistons yes, hence my remark of being a bit too heavy for a bike  :lol8:
I used to use a company in Booysens area in Jo,burg in the 1980’s to do that type of stuff on castings. 👍😎
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: jaybiker on April 18, 2020, 11:07:50 am
Diesel type 2 strokes with short skirt pistons won't work. A long skirt piston is required to keep the inlet ports covered on the upper part of the stroke to prevent air being blown into the crankcase.

Add on the necessary valves, camshaft and the supercharger and the advantage of lightness and simplicity is gone. Your bike might as well be a 4 stroke.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: sidetrack on April 18, 2020, 11:42:47 am
Cant see anyone bothering with 2T anymore as electric will be the future. Bike sales worldwide is down as well, can only hook millenials with an ipad dash and green safe bikes
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 18, 2020, 02:26:59 pm
Diesel type 2 strokes with short skirt pistons won't work. A long skirt piston is required to keep the inlet ports covered on the upper part of the stroke to prevent air being blown into the crankcase.

Add on the necessary valves, camshaft and the supercharger and the advantage of lightness and simplicity is gone. Your bike might as well be a 4 stroke.

This is the big problem in my opinion, the complexity. I think that TPI, as currently run on the KTM/Husky's, is the ultimate in 2stroke development.

Even direct injection demands a very high-pressure pump in the system.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: BuRP on April 18, 2020, 04:34:36 pm
Diesel type 2 strokes with short skirt pistons won't work.

Better tell that to Wartsila, they do use short sleeved pistons in all their engines!
Using Crosshead conrods there's no sideways force on the piston first of all, and the use of valves means there's no ports in the cylinder - hence the tiniest piston-height will do fine, just ringlands basically!
Piston controlled stroker-diesels are largely gone today, they're too small to compete with the higher efficiencies of the larger motors, 4strokes mostly.
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Welsh on April 18, 2020, 04:50:46 pm
Diesel type 2 strokes with short skirt pistons won't work.

Better tell that to Wartsila, they do use short sleeved pistons in all their engines!
Using Crosshead conrods there's no sideways force on the piston first of all, and the use of valves means there's no ports in the cylinder - hence the tiniest piston-height will do fine, just ringlands basically!
Piston controlled stroker-diesels are largely gone today, they're too small to compete with the higher efficiencies of the larger motors, 4strokes mostly.

Sasolburg have a bunch of those Wartsila's from memory.  :sip:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: 2StrokeDan on April 18, 2020, 05:04:32 pm
Katana's Avatar is the cause this thread is now at ship's engines. :pot:
Title: Re: When would the Japs catch up with 2T, if ever?
Post by: Sabre on April 18, 2020, 09:08:23 pm
Do you have any idea of the size and weight of a ship engine piston?

Yes - I've stood and sat on them whilst fixing their cracks.... with this stuff, watch the video clip:
https://www.metalockengineering.com/en/typical-repairs/metal-stitching/
Cast iron pistons yes, hence my remark of being a bit too heavy for a bike  :lol8:
I have last heard of this technique in the 80's, glad to see it is alive and well and running  :thumleft: