450 V-twin for a sport quad. It's coming...

[GPracer2500]

...maybe.

Aprillia already has such an engine. It's for their new RXV enduro bike and SXV supermoto bike. Comes in both 450cc and 550cc versions. I've yet to see any facts about HP, but the 450 version is suppose to put out 55. :D I'm not inclined to doubt that since the engineers from that part of the world are known for making dead serious HP in similar sized engines (KTM anyone?).

I have no reason to think Aprillia plans to build a quad. But wouldn't it be cool if somehow this V-Twin 450 made it into Can-Am's currently under development, suppose-to-be-race-ready 450 sport quad?? Extremely unlikely? Sure--but it's still fun to imagine. I'm sure penty of Yamahondkawzuki loyalists would bite their tongue and buy a Can-Am (Bombardier's new, old name) if it had a 55 hp twin. But what's MORE realistic is that the RXV/SXV bikes will prove that small displacement multi cylinder engines can work in high performance off-road applications. Applications where engine weight and size can only get so big before singles just make more sense. THAT might encourage the Big Four to put their R&D to work on something new and innovative.

Why the hell can't Honda build an engine like this and put it in a sport quad? Maybe make a 450 and a 550 or 650. I know they could if they wanted to. Sometimes they are conservative to a fault about what products to bring to the public. :mad: Yamaha could (and maybe would) do it though. Keeping costs down would be tough. But even if they cost $1000-1500 more than a single I bet they'd still sell tons of them.

Call me a freak, but it's these possibilities that can keep me up at night. :huh I'm kidding of course. Sort of. ;)


The below images are snippets from the RXV/SXV catalog.

http://img207.imageshack.us/img207/54/untitled30fg.png

http://img212.imageshack.us/img212/4773/untitled3bt.png
http://img211.imageshack.us/img211/6989/untitled27zc1.png

Here's the RXV to help provide a sense for how compact this engine really is:
http://www.2wf.com/images/upload/rxv_3-4_ant.jpg

:D

[ohsobad_chevy]

That is going to get interesting. :p

[tltcracing]

this would be cool. i think it would catch on in the unlimiteds if someone stuck one of the motors in there quad.

[Iliketogofast]

Yeah, but how much does it weigh?

[GPracer2500]

Originally posted by Iliketogofast
Yeah, but how much does it weigh?

Don't know. I think they've gone to considerable lengths to keep the weight down but even so--you've got to imagine it weighs more than a comparably displaced single. But maybe not? I dunno. I does look tiny for what it is.

It's interesting that the AMA has banned twin cylinders from SX/MC competition. Could a twin compete at the highest level in SX/MC? We may never know....

Here's some more pics:

http://img227.imageshack.us/img227/2083/rxvenginecrop4ak.jpg

Looking at this one, for a second I though what the hell kind of piston is THAT? But then I realized I was looking at the sleeves. They look to be plated aluminum sleeves that fit into the crankcases themselves, rather than having separate cylinders.

http://www.motociclismofuoristrada.it/edisport/moto/gallery.nsf/HFoto/ApriliaRXV4.5.Iltest06FotoGrande/$file/06.jpg

[Iliketogofast]

In that big pic of the motor, what's that electrical connection to the lower right of the water pump for?

[GPracer2500]

Originally posted by Iliketogofast
In that big pic of the motor, what's that electrical connection to the lower right of the water pump for?

That's gotta be a cooland temp sensor.

[wilkin250r]

I just can't see it. Sure, it would be interesting, but we ALL know that horsepower doesn't win races. Not only would it certainly weigh more than a comparable single-cylinder, it also introduces other complications. With the V-twin design, the intake is directly between the two cylinders. This means you either need to bring the carburetion in from the top (and increase the quads height and raise the center of gravity), or you need to bring it in from the side and possibly run into clearance issues with a big ol' carburetor sticking off the side.

Bringing a carburetor in at the top isn't a problem on a dirtbike, they generally have lots of height to work with. Not so much on a quad.

I bet it revs out to better than 12 thousand rpm, though :devil:

[GPracer2500]

13,000 in supermoto trim. :devil:

I was imagining the fuel tank being moved (somewhere--maybe where airboxes are currently found?) so traditional fuel tank space could be airbox space. And I wouldn't be too surprised if the ATV racing sanctioning bodies killed the idea by way of the rulebook before it could ever happen.

How about a Raptor-type quad though--something intended for more than just racing? HP may not always win on the track but it rules the dunes....

Maybe a parallel twin would work better in a 450 racing machine? We could even get really crazy and imagine a flat twin...

[wilkin250r]

And that's probably the real nail in the coffin. The proof is in the (lack of) popularity of the V-force. If it can't be raced, it just won't get the sales, and manufacturers know that. So the natural conclusion is that if it can't be raced, it won't be produced.

I would be worried about moving the fuel tank. You're moving a significant amount of weight rearward. Not only that, but the fuel tank is a variable weight, it fluctuates. The fluctuation isn't so bad when its sitting on top of the motor, because it's weight is directly along the axis of the motor, and thus almost directly along the axis of the center of gravity. Any fluctuation there doesn't significantly move the center of gravity.

However, adding and removing twenty pounds directly under seat WILL significantly move the center of gravity.

A parallel twin would work very well (Yamaha Banshee), but they tend to be a little bigger and heavier. The crankshaft needs to be much longer, and then the added metal of the surrounding crankcase.

[GPracer2500]

Dang, wilkin... :grr: ...you and your reasoned logic. :blah:

I'm holding out hope that someday a new and viable twin-cylinder sport quad hits the scene...something that holds to the spirit of the RXV/SXV bikes. In other words, not V-Force like.

:)

[Iliketogofast]

What are those tan looking gizmos coming off the top?

I think that electric plugin is an oil temp - it screws in and out like a spark plug! And look at the passages that seem to lead to it. Plus, it's below the water pump.

[GPracer2500]

Originally posted by Iliketogofast
What are those tan looking gizmos coming off the top?

I think that electric plugin is an oil temp - it screws in and out like a spark plug! And look at the passages that seem to lead to it. Plus, it's below the water pump.

That could be an oil temp sensor. Or maybe it's an oil pressure switch. Your guess is as good as mine, really.

Tan gizmos? Are you talking about the throttle bodies sticking out of the inner/top of each head? It's fuel injected.

ETA: Now that I'm really focusing on that plug-in, I think you're right. Oil temp or oil pressure makes more sense. Water temp sensors aren't normally found on the crankcase--they're usually in a thermostat housing near the radiators.

I bet that big round black thing under that plug-in has an oil filter behind it.

[EXevan91]

the tan qismozs on the very top are fuel injecters so that kills wilkers carb complaints.

[tltcracing]

i think a v twin would catchon if done in the right stle. the v force didnt work very good because is is very heavy, shaft driven, and automatic. i think if you retro fit a v twin into todays 450's then it would catch on. oh and if its fuel injected whats the use in thinking about where to put a carb? it doesnt need it and you could just put the air filter somewhere it would fit then run a tube to the motor.

the bombardier 800 uses a V-twin engien.

[Iliketogofast]

Look at the specs... It comes in a 550 too!

[GPracer2500]

Originally posted by the gangsta
the bombardier 800 uses a V-twin engien.

But it's big and heavy along the same vane as the V-Force. There's actually a bunch of quads that have twins but they all lean toward the utility-quad side of things.

[stalefish_132]

i can see it now....... that 450 V-twin in a C-dale frame. now that i would like to see:eek2:

[wilkin250r]

The V-twin isn't new to quads, several utilities have them. But the closest it has ever come to a sport quad is the V-force, at 900lbs and automatic transmission. Hardly all that sporty.

[GPracer2500]

Here's another interesting engine--this one a parallel twin from Yamaha. It's 499cc and fuel injected (twin Keihin 43mm throttle bodies--yes Keihin makes FI systems). It even has a knock sensor that retards ignition timing to protect the engine from detonation. It has 3 intake and 2 exhaust valves per cylinder and a 77mm x 53.6mm bore/stroke. For you engine spec junkies you'll notice those are the exact same specs as the YZ250F MX bike. Yep, this twin is a pair of YZ engines spliced together. Cool.

Peak HP of 80 arrives at over 11,000 rpm. :devil:

This engine is being used in Yamaha's new for 2007 Phaser snowmobile. Notice there is no attatched gearbox--snowmobiles use a different drive system. But I have no doubt this engine could be adapted with a gearbox for ATV use.

These pics are a little grainy but I couldn't find any good ones.

http://img225.imageshack.us/img225/1113/scan00047ku.jpg

http://img207.imageshack.us/img207/6842/scan0002small5ci.jpg

Four stroke, 65+ hp Banshee anyone?

[Grant Casey]

i reckone that thing would fly

[Iliketogofast]

Four Stroke Banshee? Pfft.... Junk.

[ohsobad_chevy]

Originally posted by Iliketogofast
Four Stroke Banshee? Pfft.... Junk.

4 strokes rule... lol.... Just kiddin'... Im not trying to start world war 3. :devil: