| Author | Message | ||
     Rfischer |
Rotax, commissioned by parent co., Bombardier, has developed a Direct Injection 2-stroke motor for Ski-Doo snowmobiles. 800cc, 120 hp, clean. Doesn't use oil injection so combustion by-products are similar to 4 strokes [which BTW also run much cleaner with DI, as do diesels]. Being a 2 stroke, it is markedly lighter than the comparable 4T it will replace. Torque is outstanding, again, because it is a 2 stroke. Seems to this simple staple salesman the motor would be DynoMite in a bike chassis, either as a 2 or 4 cylinder, inline or V. Erik, oh Erik....... | ||
| Limitedx1 |
a dirt injected single dirt bike would be rad too!!!! ive often dreamed when they would do this. the two stroke is just too bad a$$ of a motor to eliminate | ||
| Cityxslicker |
dont get me started about a 400-500 cc dirt squirter.  I guarantee Buell will come out with one, the moment my build is done. It seems to happen to me every time. | ||
| P_squared |
In that case, GET BUSY and FINISH it! (That way the rest of us can get 1 too) | ||
| Cityxslicker |
The Muell project is moving, the motor is out, and the frame is getting cleaned and powder coated, Assembly starts next week. I have all Buell Blast body work, Acerbis Front shield and dirt fender. It will be based on the Honda XL250, total cost 500 bucks. Target is to be dirt road ready by March 15th | ||
| Buellinachinashop |
Outboard mfg's have been doing this for years. Merc's OptiMax, Yamaha's HPDI and Evinrude's FICT ad ETec. More power and meets all the 06 EPA standards. | ||
| Gunut75 |
mmmmmmmmmm.......350lb., 100hp. road bike.........mmmmmmmmmm  | ||
| Gunut75 |
I still fingerport a few Evinrude V8 2 stroke blocks now and then. NOW THATS A V8! 400 hp. carbed!  | ||
| Bill0351 |
"Doesn't use oil injection" I guess I never really thought about it, but is there any reason that a 2 stroke can't use the oiling system similar to a 4 stroke? Bill | ||
| Jlnance |
Bill - 2 strokes need their intakes above atmospheric pressure so they can blow the exhaust out of the cylinder. One way to do this is use the bottom of the piston as an air pump. The sealing required to make that work interfere with the oiling setup that would typically be used in a 4 stroke motor. You don't have to use the bottom of the piston as your source of pressurized air. For example, you could turbocharge the motor, and give it a conventional oiling system. But the bottom of the piston way inexpensive, lightweight, and simple, so this is why you see it so often done. | ||
| Ducxl |
Say..Mr. Fischer,you're no relation to Fischer motorcycles are you? And,wasn't there another crazy 2 stroke snowmobile engined BIKE? Torlon? No,not Torlon,that's a form of plastic.But something like Torlane? Two smokes are terribly inefficient engines aren't they? | ||
| Diablobrian |
Tularis | ||
| Johnnylunchbox |
Orbital Engines of Australia is the pioneer behind the direct injection of 2-smokers. I lost a fair bit of change investing in their company. They turned from manufacturer to licenser of their ideas to companies like merc and piaggio. Guarantee that the Rotax is using OE technology. Please buy lots of their stuff and help my investment. | ||
| Boltrider |
Don't those 2-strokes have perforated cylinder walls? No valves either, right? That idea is just wild. I've never seen one torn apart. (Message edited by boltrider on February 26, 2009) | ||
| Dbird29 |
I rode one of the SkiDoo 2 stroke sleds with the engine reverse. Too Cool. The motor stops and then starts again in a reverse direction. Hit the starter button again and it stops and starts rotating in the normal direction. Don't think you could do this with a 4 stroke. | ||
| Old_man |
The engine I design in my head for my perfect bike: 500 CC V twin 2 cycle, direct fuel injection, variable opening rotary valve. Mechanically(automatic)variable length single exhaust. Oil injection lube - I've owned bikes with this feature, they don't smoke or use too much oil. (Message edited by old_man on February 26, 2009) (Message edited by old_man on February 26, 2009) (Message edited by old_man on February 26, 2009) | ||
| Limitedx1 |
unless its a yamaha blaster, then the oil injection pump starts to get bad then BOOM, pieces of piston everywhere! | ||
| Natexlh1000 |
Remember the bimota that had a 500cc two stroke with direct injection? It failed to work. I hope this one works. | ||
| Rfischer |
The technology being used by Ski-Doo came from Ficht GmbH of Austria via Evinrude Marine, which Bombardier bought several years ago. Ficht hadn't been successful with the design, but Evinrude carried on with the development. In fact, in 2004 they won the EPA Clean Air Excellence Award for their efforts. The other outboard mfr.'s use a variation of the Evinrude/Ficht engine under license I believe. Oiling of the top end of the Ski-Doo motors comes from the crank side, not by gas/oil mixture. And, no, I have no connection to Fischer Motorcycles, tho' I am familiar with them. My present motorcycle industry involvement is Highland Grp. AB in Sweden. www.highland.se | ||
| Hootowl |
Actually, I think you could run a 4 stroke in reverse, as long as the cam continued to spin the same direction. | ||
| Fast1075 |
Mercury marine used to build inline 6 outboards that were referred to as "Dock Bumpers" that used the run both ways idea to simplify the lower unit...it worked..but due to the time it took to shut the engine off and restart it in the other rotation...there was a lot of boats running into docks....hence "Dock Bumper". Gunut...years ago while fishing as a non-boater in a Muscular Dystrophy benefit bass tournament, I was drawn to fish with a touring pro...the boat was an 18ft Shadow tunnel hull (very rare bass boat configuration)...anyway, the motor was an Evenrude V-8...the dash of the boat had a plate that said "OMC Performance Group"...that boat would run an honest 90 mph...that was fast. (Message edited by fast1075 on February 26, 2009) | ||
| Bill0351 |
"2 strokes need their intakes above atmospheric pressure so they can blow the exhaust out of the cylinder." Thanks for that information. I looked it up last night to find out more. I guess I just never thought about how they evacuated the exhaust and still got intake on the same stroke. Now I know. Back when I used to be into boats, I remember reading a review of a 4 stroke vs a similar HP oil injected 2 stroke outboard. By the end of the test, the 2 stroke had only burned slightly more oil. It's just that one was supposed to burn oil, and the other just did it anyway. I wish I remembered what engines they were comparing. | ||
| Rfischer |
I think a couple posters are confused by the term "Direct Injection" as used in these new motors. It has nothing to do with oil injection for lubrication; it is a very sophisticated, electronically controlled, injection of fuel directly into the combustion chamber, rather than conventional injection into an intake or port. The technology was first developed for aircraft engines in the 40's, used by Mercedes for the first time in an automotive application in the 300SL of the 50's, and has been more recently used by M-B, BMW, Porsche, GM etc. Bosche OEM mostly. What is new and innovative is Ski-Doo's Evinrude 2 stroke technology, which hasn't been done successfully before. 2 strokes have been disappearing due to inability to meet pollution standards, poor fuel economy, and power output that couldn't keep up with the newest 4 strokes. This new technology addresses all those issues, while keeping the advantages of less complexity, lighter, less costly maintenance, and so forth. | ||
| Fast1075 |
Rotax used to build some pretty fierce old school rotary valve 2 strokes. I wrenched a couple of the 250 Can Am motocrossers back in the day...It would be cool to see a modern version...direct injection dry throttle body...oh yeah!! mondo power...super light...wow! Old_Man...you must have kart experience mentioning mechanically variable exhaust..I had a kart with a Komet motor that varied the stinger lenght for torque out of the turns.. | ||
| Arcticktm |
Interesting conversation. Some random thoughts: Rotax (Ski-Doo) has had a so-called semi-direct injection (SDI) 2-stroke snowmobile engine series since around 2002/2003. It puts in the fuel in the transfer ports, just before it enters the cylinder. It is definitely cleaner than conventional 2 stroke EFI sled motors, but not quite to a 4 stroke level (though 4 stroke emissions go up dramatically when you really push it, like the early Yamaha sled 4 strokes). Direct injection has also been tried by Arctic Cat and Polaris in the past. Polaris got sued big time for stealing the technology. Cat had trouble with reliability and cost (in development - it never made it to production). Cost and reliability are the 2 things to look for if Rotax is to succeed this time. DI requires much higher pressures than conventional EFI, and a sled is a hostile environment with cold, shock, heat, moisture, erratic fuel quality and seasonal storage. Of course, 4 strokes cost considerably more to build than 2 strokes, so there is some room to play. Detroit Diesel used to be famous for 2 stroke diesels, from 1930's until 2000. They had overhead exhaust poppet valves (not ports), and a "normal" crankcase oil system. The breathed through ports in the cylinder wall, and had blowers (superchargers) that were gear driven, to keep a pressurized airbox. Very good power/weight in their day, though a lack of continued development made it easy for 4 strokes to take over in the 80's. Big ocean going ship diesels are still 2 strokes. Rfischer - how does the new Rotax motor scavenge, if it's not crankcase scavenged? I will have to check this out. | ||
| Rfischer |
Not sure how these scavenge. However, the oil pump is external and fogs from the crankcase, so I'm assuming the motor scavenges from there by ports in the cylinders. The 600cc and 800cc motors are in production so might have to visit a dealer to ask about this. Very interesting stuff with lots of power sports apps. | ||
| Old_man |
Fast1075, No cart experience, I had never seen it applied anywhere (variable length expansion chamber) but I think it a good idea. | ||
| Husky |
From http://www.rotax.com/en/Media.Center/Press.Release s/1/20081014.htm BRP-Rotax & PETRONAS rolls out high performance engine for snowmobiles The engine which rolled out from BRP-Rotax's assembly line in Gunskirchen, Austria on 4 September 2008 marks yet another significant milestone for PETRONAS which has been involved in the development of engine technology since 1997. Jointly developed by both parties since November 2005, the 130 horse-power engine known as Rotax 4-TEC 1200 brings Formula 1 racing and automobile technologies to the snowmobile world. The engine, which delivers the best torque in its class, is the first success story coming from the flourishing technical partnership between BRP-Rotax and PETRONAS established five years ago. Rotax 4-TEC 1200 will be BRP's first high performance four-stroke snowmobile engine and it will provide its customers with a more competitive product offering for 2009. Husky | ||
| Hootowl |
"The technology was first developed for aircraft engines in the 40's, used by Mercedes for the first time in an automotive application in the 300SL of the 50's, and has been more recently used by M-B, BMW, Porsche, GM etc. Bosche OEM mostly." VW uses direct injection in their diesels also. | ||
| Jlnance |
Aren't all diesels direct injection? |
