Lets face it, the greenies are gonna kill the 2 stroke. But hmm... lets think, what else can make massive power from tiny displacment and likes to rev? A wankel (Rotary engine). As a 2 cylinder 1.3 liter they made around 270 hp stock in an RX-7 and racers had no problem pulling 600+hp out of a 1.3 liter!! Only problem is they like to rebuilt more than the average car owner likes to do the rebuilding, usually only apex seals (equivilant of rings). That sounds familar too. Only way they differ from 2 strokes is that 2 strokes like funny stuff on the exhaust end (large expansion chambers) and wankels like funny stuff on the intake side (turbo's). Has anyone ever made a small wankel??? there was a chainsaw and a lawnmower and some other stuff made back in the day. So heres the idea, replace 2 smokes with rotor engines. See guys its not so bleek, you can still have a tiny engine with few parts, loves to rev, massive power, and a massive power band, except a turbo instead of a pipe causes it.
If only honda instead of Ford had bought Mazda [img]i/expressions/face-icon-small-sad.gif[/img] cause there the only company with high tech rotaries.

On a side note Rotary engines are technically 4 stroke.

 

A few years ago.....We had a "Malibu GrandPrix" here were I live. They had your ordinary go-karts, and then they had some miniature race cars, and then they had the fast one. The miniature had a beefy motor in it, but I am not sure what it was. The fast one, which you had to be in a club to drive, had a small rotary motor in it that was smaller then the RX7 motor but large enough to push that car around the track at good speed.

If you could get a hold of them (Malibu Grand Prix), they might have an answere for you. This might be something to look into.....

James

 

that's a good idea,i have a 13b that i was going to fix to put on a sand rail,but better yet i have a lt 250 that will like to have some more hp,the only thing is that rotary don't last too long,cause they don't like heat.

 

Effiecency and emissions is what killed the rotary. This is the same things that are killing the 2-strokes. Jakal, I have many friends with all different years of RX-7's. I am sure none of them are pushing 270 horsepower in stock form without the help of massive turbos.

With the added weight and expense of turbos and totally redesigning atv engine priciples, you would be better off sodium filling Ti exhaust valves in the Raptor, redesign the ports, going to FCR carbs, and other little items that can make an even quicker reving, more powerful, lightweight four stroke. You would then have effiecency, emissions, and dependability to boot.

Isn't all rotary engines made of iron. Wouldn't the expansion of alum cause large clearences between the rotor and chamber which decreases seal and compression ratio (which is VERY low anyway). An iron engine would defiently be too heavy for an atv chassis.

Have you noticed how much more advanced 4-stroke have became since the demise of the rotary? I love my 2-strokes, please don't get me wrong. I am not advocating the killing of these engines in 2006. I am planning on keeping my banshees until pistons are no longer offered. However, in every aspect of life, you should progress. I feel that going to rotary (you even said they are like 2-strokes) will be regression or at most, staying the same.

I don't mean to step on any toes, but the companies have to make money without dumping cash into a model that will be killed in a couple of years. Yamaha has known the end was coming for two strokes for years. That is why they have never changed the banshee or blaster (although they needed it). The other companies chose to get out of it totally so they didn't end up with a bunch of bikes sitting around they couldn't sell because the US gov decide to change the laws. This is exactly what happened with the three-wheelers. Even if they made a emissions rotary in 2003, it doesn't mean the gov won't change the rules in 2005.

 

The rotary motor isn't dead yet! Mazda is coming out with an RX-8 next year that will have a 255HP naturally aspirated rotary motor. Alky is right in that the rotary is a dirty motor. Mazda has spent much time and $ to get this new motor clean. Norton made a Grand Prix race bike in the late 80's or early 90's that had a rotary motor. However, I don't think it ever raced.

 

2 strokes are far from being dead also. Bombardier has made huge leaps in 2 stroke technology for both boat motors and skidoo motors. The end result is much less emitions then 4 strokes and more fuel milage. Not to mention more power and lighter weight.

All the old problems like fuel blowby and misfiring at idle are taken care of. The new generation 2 strokes start and idle like clockwork with out any vibration. Then they pull all the way up to there powerband as smooth as can be with no smoke or emmitions from the exhaust.

A University project got a 2 stroke down to 99% less emmitions then current 2 strokes.

So 2 stroke have a future and will be a big part of atvs, sleds, and outboards.

As for the rotary. Only a 2 stroke and a rotory engine are recipricating engines. These engines are far more efficent power makers then 4 stroke. Rotary engines could be the future depending on what mazda does with the RX-8. I owned a few Rx-7s and had the motor out a few times. I could lift the motor by myself it was so light but it pulled harder then my 2000 grand prix GTP superchared.

4 strokes have a major disadvantage when it comes to power delivery. IMO 4 stroke will be the first to die because these engines have more moving parts, are larger and heavier, and make less power.

Think about it. THe only advantage a 4 stroke has is emmitions. Now that 2 strokes have that. Theres no reason to keep them around. The only reason 4 strokes have a higher longivety are becasue more rings are used. And there not reved up to snot when ever there used. Run a 4 stroke at 8000 rpm all day like in a sled and lets see if it last more then 10000km.

 

see....if knowsalot was still here, he'd know.[img]i/expressions/face-icon-small-wink.gif[/img]

 

The reason Rotary engines were having problems is that noone put a lot of time and effort into them like they do on four strokes. Same way with two strokes. Everyone spends out the **** to develop a bad idea when they have 2 good ones staring them in the face. IMO four stroke is least efficent, 2 stroke next, then wankel is most, now thay have some constant combustion engines that work kind of like a rotary but are even more efficent. That new Renesis (RX-8) engine looks very sweet, 250 hp with no turbo, i wouldnt buy it though because there gonna make a turbo version too [img]i/expressions/face-icon-small-smile.gif[/img]

In the last years it was made the RX-7 had a 0-60 of around 4.5 and around 270hp, the earlier ones werent as good. Heck, chevy designed a 4 rotor corvette with 450hp back in the 80s, didnt ever make it though cause the got no B@11s. Four strokes need to die and go away IMO. Quit dumping development time and money on a dead horse.
Analogy: Our government instead of developing guns decides to spend 3 billion dollars to make the bow better and give the gun a back seat because we have more trees to make bows than mines to make iron. 10 years down the road our troops are equiped with state of the art, low energy, high yield, laser guided arrow, auto trajectory bows. Meanwhile Cuba invades with lever action rifles and rapes us.

 

<< The reason Rotary engines were having problems is that noone put a lot of time and effort into them like they do on four strokes. Same way with two strokes. Everyone spends out the **** to develop a bad idea when they have 2 good ones staring them in the face. IMO four stroke is least efficent, 2 stroke next, then wankel is most, now thay have some constant combustion engines that work kind of like a rotary but are even more efficent. That new Renesis (RX-8) engine looks very sweet, 250 hp with no turbo, i wouldnt buy it though because there gonna make a turbo version too [img]i/expressions/face-icon-small-smile.gif[/img]

In the last years it was made the RX-7 had a 0-60 of around 4.5 and around 270hp, the earlier ones werent as good. Heck, chevy designed a 4 rotor corvette with 450hp back in the 80s, didnt ever make it though cause the got no B@11s. Four strokes need to die and go away IMO. Quit dumping development time and money on a dead horse.
Analogy: Our government instead of developing guns decides to spend 3 billion dollars to make the bow better and give the gun a back seat because we have more trees to make bows than mines to make iron. 10 years down the road our troops are equiped with state of the art, low energy, high yield, laser guided arrow, auto trajectory bows. Meanwhile Cuba invades with lever action rifles and rapes us. >>



There is a lot of truth in what you said. From what I remember from my Physics classes the highest efficiency you can get from a 4 stroke engine was around 12%. The rotoray had apotential to have 60% efficiency. I never saw the stats on a 2 stroke, but Im sure it is higher than a 4 stroke. Your absolutley right about the fact that if 2 strokes and rotory engines had as much time and effort put into them they would be much further along.

 

I know we are talking alot of hp out of these raoary engines, but what about the torque. I don't think you need alot for a quad, but i don't think that rotary engines make the torque that 4 storkes do. Like pulling off of the line. Or riding were low end counts. Just a thought. I am also curious on how they would do in a quad. Blaze