new idea for a two stroke

[slamdak8782]

has anybody ever thought of putting the intake straight to the crankase that way you could separate the cycles better and burn cleaner that way they could build the two stroke again?

[Lasher]

Are you talking about the case reed intake first appearing on the 2002 Honda CR250R?

(I had to google the year but I remember the bike motors had them for years)

Cleaner burning 2 strokes are called "direct injected" and are being used in watercraft. I remember hearing about how they are cleaner burning that the 4 stroke motors in other makes.

[atvmxr]

ummm thats what they did in the 70s and early 80sss

85-86 LT250r too... ;)

[troybilt]

Originally posted by atvmxr
ummm thats what they did in the 70s and early 80sss

85-86 LT250r too... ;)

That's what I thought too...

[Langbolt]

Bombardier uses that Technology in their 2-stroke Snowmobile engines - Ski-doo & Also in their Out boards - Evinrude

Now....if they used it in their QUADS with the DS450 chassis they could make a really sweet 250-330....

I wonder if Rotax is still making the 250cc 2-stroke powervalved motors that were used in the REBEL 250R ????

That would definitely be a resurrection of the 2-Stroke in the ATV Community.

We can all hope that that does indeed happen someday!!!:devil:

[rustyATV]

Originally posted by Langbolt
I wonder if Rotax is still making the 250cc 2-stroke powervalved motors that were used in the REBEL 250R ????

No, they are not. That motor was the 257GSi (I think the 257GS was a non powervalved version). It was popular in karting for a while and was also used in the ATK 250LQ and 260LQ bikes.

Hard to find parts for, though when I was searching it was suggested that some Karting suppliers had contacts. ATK is supposed to still be supporting them as well.

[Velvet-Casket]

If im not mistaken some tiger 3 wheelers were built like that.

[Derrick Adams]

Pretty sure Can-Am planned to put their 2 stroke motor in the DS450 right up till production but the AMA squashed it. There's a real interesting thread on it in the DS450 forum.

I wish they would have. I would have one sitting in my garage beside my 250R right now.:eek2:

[Langbolt]

Really ?

It was the AMA that stopped BRP from producing it ???

Arrrggh!!!

That would have been one sweet, light & powerful Quad!

:mad:

[SilverLake250R]

I would have had one in my garage as well. I mean, I am a Honda man, but I like 2-strokes more than Honda.

[Langbolt]

Here's the LINK:

http://www.exriders.com/vbb/showthread.php?s=&threadid=432839&perpage=10&highlight=rotax&pagenumber=1

[C-LEIGH RACING]

According to Chuckie's Can Am Rep, I asked him direct if the DS450 was ever intended to be a 2 stroke version & he told me that was just a rumor that got started.
I was sure hoping it was true that it was to be, but accroding to him sadly not.
Neil

[Derrick Adams]

I would seriously consider an engine swap into one of those Can-Ams if I run across the right deal on a roller someday. Wish the chain was on the other side though, sure would make it easier.

[rustyATV]

Originally posted by Derrick Adams
I would seriously consider an engine swap into one of those Can-Ams if I run across the right deal on a roller someday. Wish the chain was on the other side though, sure would make it easier.

Guess which side the chain is on with the Rotax 257GSi....

;)

http://www.dirtrider.net/gallery/files/6/0/1/6/8/100_0392Medium.JPG

[regg187]

Originally posted by Velvet-Casket
If im not mistaken some tiger 3 wheelers were built like that.

Tiger 3 wheelers?, wow that takes me back, wayyyy back, I remember helping Jimmy White and another friend at Races in PHX at the Dawning of Quads, Jimmy on his Factory Tiger, Honda with it's water pumper 3 wheeler every pro waiting outside the promoters trailer to get paid. Donnie Banks , Mike Coe, Jimmy White, I mean everyone was there! SOME REALLY GREAT MEMORIES!

[89trx250r]

thought you guys would be interested in this its obviously a dream but hey

http://www.offroad.com/atv/feature/rebelstar-250-proquad-29104.html

also if you search rebelstar in Google images you can get some better close ups cause the links on the original site don't work anymore :(

[Langbolt]

Hmmmm Anyone else notice the phone number for Rebel star ?

1 800 4LS RACE is LONESTAR Racing

I wondered who made the Frames for them

You would think a company as big as Lone Star could swing a deal with ROTAX for some 2-Stroke motors and build some Complete QUADS.....

Hmmmmm

[89trx250r]

i think they were full lonestar set ups if you look at the pics its deff lonestar arms stem swinger and its hard to tell frame from just those pics but i would assume its one of theres the funny thing is idk if any of theese besides this one were ever built its so hard to find any info on them at all

[mxduner]

Originally posted by 89trx250r
i think they were full lonestar set ups if you look at the pics its deff lonestar arms stem swinger and its hard to tell frame from just those pics but i would assume its one of theres the funny thing is idk if any of theese besides this one were ever built its so hard to find any info on them at all I wanna say that rebel star also made a full out 240 blaster motor baased machine to. maybe they just modded a lot of them:confused:

[rustyATV]

Originally posted by 89trx250r
i think they were full lonestar set ups if you look at the pics its deff lonestar arms stem swinger and its hard to tell frame from just those pics but i would assume its one of theres the funny thing is idk if any of theese besides this one were ever built its so hard to find any info on them at all

I recall this was a partnership between Lonestar and now defunct Last Rebel Racing.

Wonder if you called Lonestar and asked if they'd still have the jigs for that frame.

[89trx250r]

^ makes perfect sense now i understand "rebelstar" and i would love to see someone either put a 257 rotax in the ds 450 frame or a legit 250r with the rotax motor hybrid like that company used to do i guess youd just have to flip the axle and put the sprocket on the right?

[Derrick Adams]

Is that Rotax engine still available? From the looks of it, its counter balanced and has a 6 speed. What kind of aftermarket is there for it, if any?

[troybilt]

Doesn't the 2004 CR250r motor have what you're talking about?

[Ruf Racing]

No CB Troy.

[slamdak8782]

Cool I figured that would work better. Didn't know if it had been done

[troybilt]

Originally posted by Ruf Racing
No CB Troy.

no kidding...

The OP asked this question


new idea for a two stroke
has anybody ever thought of putting the intake straight to the crankase that way you could separate the cycles better and burn cleaner that way they could build the two stroke again?

I saw a 250R engine years ago built with a disk valve port running of the crankshaft. Intake timing was controlled separate by crank rotation, and independent of the rest of the engine cycle. This set up performed very well, and allowed you to set intake opening & closing to precise and optimum intervals…

The work involved was substantial (lots of welding and machining, as well as new components) and cost prohibitive, however; it was a monster in HP output…

Carlos.

[89trx250r]

http://www.sae.org/mags/AEI/POWER/8157

thought this was pretty interesting figured id share with yall :)

[mxduner]

Originally posted by acecarlos
I saw a 250R engine years ago built with a disk valve port running of the crankshaft. Intake timing was controlled separate by crank rotation, and independent of the rest of the engine cycle. This set up performed very well, and allowed you to set intake opening & closing to precise and optimum intervals…

The work involved was substantial (lots of welding and machining, as well as new components) and cost prohibitive, however; it was a monster in HP output…

Carlos. ski doo sleds used them for years on their sleds, but eventually went to reeds. You could buy different discs to alter intake timing for tuning. you just didn't want to leave anything loose lmao. I think they called it a rotary valve intake.

[troybilt]

Originally posted by 89trx250r
http://www.sae.org/mags/AEI/POWER/8157

thought this was pretty interesting figured id share with yall :)

That is definitely cool. Why mess with carbs reeds and crap-olla when you can inject directly into the cylinder, much simplier. Also no need to worry about crank-case scavenging either, i.e. not mixed fuel?? Looks like the CC is sealed off.

[mxduner]

Originally posted by 89trx250r
http://www.sae.org/mags/AEI/POWER/8157

thought this was pretty interesting figured id share with yall :) I didn't know they were coming out with a 800 version for the sled, but that is good to know. The 600 version has been out for a couple years now. They use soo much less oil. They claim 80% less and no smoke. This is the technology that will keep 2 strokes alive. They also have a 3 year warranty that covors SPARK PLUGS! The outboard (e-tech) version is maintenance free for tthe 1st 3 years as well.

[89trx250r]

yea the motors seem awesome for sure but they also seem quite tech with the magnetic injectors etc hopefully they can figure out a way to scale them down from 600-800's cause i bet a little 250 would be quite potent

[troybilt]

Originally posted by 89trx250r
yea the motors seem awesome for sure but they also seem quite tech with the magnetic injectors etc hopefully they can figure out a way to scale them down from 600-800's cause i bet a little 250 would be quite potent

Exactly, a guy/gal could build one from the components of this 600/800 system?

[89trx250r]

the motors are made by rotax to so theres probably parts available for fair price

[rustyATV]

Originally posted by acecarlos
I saw a 250R engine years ago built with a disk valve port running of the crankshaft. Intake timing was controlled separate by crank rotation, and independent of the rest of the engine cycle. This set up performed very well, and allowed you to set intake opening & closing to precise and optimum intervals…

The work involved was substantial (lots of welding and machining, as well as new components) and cost prohibitive, however; it was a monster in HP output…

Carlos.

Disk valves used to be the way to go until composite reeds were invented. After that, the only thing disk valves did was make things more complicated.

[mxduner]

Originally posted by troybilt
Exactly, a guy/gal could build one from the components of this 600/800 system? yes i thought of this to. My thought was to use all the electronics from the say 600, and find a way to trick the sensors for 1 cyl. as these are twins. and/or trick the ecm. or we would have to design a new ecm. i spose there is plenty different ways to do this.

my way of thinking why it aint done yet, as the cost for all the components for just 1 cylinder. The trend is getting their thou, as they started out on the outboards, 4-6 cyls. lately the twins in the sleds. give it some time thou, as stated in that article, "new epa standards for 2012" lets cross our fingers here kids.

[89trx250r]

heres some more positive reinforcement people are finally realizing no one wants 4 strokes...

http://twostrokemotocross.com/2009/06/two-strokes-strike-back/

[slamdak8782]

sweet maybe we will get a new trx250r or even better a 300r of course we will have to wait at least ten years after dirt bikes get it

RustyATV:

Good point!

I agree with you in that Disk Valves (Precise Intake Systems)certainly “make things more complicated”, I disagree they offer nothing more.

Among a few other benefits, one important one is Disk Valves (or for that matter any precise intake system) allow for specific opening and closing intake port timing, very important in all out HP.

While maybe not practical for variable throttled Motorcycles, ATV’s or any other form of 2 stroke engines developing a wide HP band, Disk Valves or Precise Intake system rule the all out HP game.

As an example; (99% of all land, sea and air 2 stroke world in line records, are held by engines employing one form or another of “Precise Intake Systems”, Disk Valves or the like