650r or 500r engine

[ninjaryda]

I've been riding my pregen 2007 250r for a while now and I love the revver' style of this engine. RPMs are fun.

Now, I've been reading about some people putting in the ex500 engine into the 250r frame. A little fabrication necessary. Curious, I looked at the 650r engine and noticed that it was also a parallel twin engine, like the 500 and 250.

The 500 engine upgrade sounded something that I might entertain down the road (once I get all the 'flair' upgrades that I want). But I noticed that both the 500 and the 650 are stroker engines. That is to say, the have a longer stroke and thus don't make their power in the higher RPM range like the 250. (Just look at the bore to stroke ration of both engines, compared to the pregen 250).

I come from the classic chevy car world. Destroking an engine is not unheard of. Has anyone tried this with the the 500 or 650 engines?

I realize that the 250 frame isn't built for high amount of torque, thus destroking would be a way to bring down some of that output. A 650r engine with a 250r stroke, makes a 446cc engine. The only problem I see with this, is the selection of cams. In the chevy world, you could go with all sorts of overlap and lobe profiles for moving around the power band. I don't really see anything like this for sportbikes, other than having custom ground cams :/

Ideas? Opinions? Complaints? Laughs?

[Racer x]

Welcome to the forum.

[Alex]

Another recent thread on this topic:

http://www.ninjette.org/forums/showthread.php?t=123109

[Falcor]

Originally Posted by Alex

Another recent thread on this topic:

http://www.ninjette.org/forums/showthread.php?t=123109

Same goal different frame haha

[vanman69]

Originally Posted by Falcor

Same goal different frame haha

are the frames really that differant?

[ninjaryda]

Originally Posted by Falcor

Same goal different frame haha

Well, maybe the end goal (more power). But I'm fairly set on not just throwing a straight stock stroker 500r or 650r in there. I like where the power band sits on this style of engine; just want that with a little more umph. And Something with peak power in the 13k-14k range.

I guess maybe this doesn't really belong in the 250r section. I'm specifically looking for cam profile options and destroking either one of these model engines, first and foremost. Not really looking at information about attaching it to a 250r frame as this point.

[Racer x]

To de stroke an engine you need a custom made crank rods and pistons. That is a lot to spend to remove power.

[vanman69]

well mate, i cant say ive ever heard of anybody de-stroking a bike motor, but another option could be a big bore 300, im thinking that would deliver its powerband in much the same way a destroked 500 or 650 would be. but in saying that, there would be alot less stress on a destroked motor then a big bore. from previous experience i would say a de-stroker is going to need a custom crank, custom cams, shave some off head and barrels, might even need custom barrels if the stroke is too short other wise compression will be ****ed. this is the reason why im thinking a 300 big bore would be the go. just as much, maybe less machining involved, depending on how far you wanted to push it of course. and think of the bragging rights

Anyway, thats my 2c

[Racer x]

The cylinders of the 300 are nicicell costed. Boring a 300 will require sleeves I think.

Why not buy a 400 ninja?

[ninjamunky85]

I think you should put a 250cc 2-stroke dirt bike motor in there. That way you'll save weight, and keep the peaky powerband. I don't remember what the redline is on the 500, but I know it's lower than the 250. Like 10 or 11k RPM.

Or alternatively, you could just sell your 250 and buy a 500. Used 500's go for prices not much higher than the 250. They also have a strong following, and are loved by their owners just as much as the 250. I like the 500 better than the 650 and it's tractor motor.

I never cared for the looks of the 500 though. My next bike will be a 300.

[vanman69]

Originally Posted by Racer x

The cylinders of the 300 are nicicell costed. Boring a 300 will require sleeves I think.

Why not buy a 400 ninja?

if your going to make it displace at least 400 or more it will take re-sleeving as well. most likely have to offset the bores and get the pistons made to suit.

[vanman69]

and whats with everyone saying buy a bigger bike??? thats not the point.

[ninjamunky85]

Originally Posted by vanman69

and whats with everyone saying buy a bigger bike??? thats not the point.

Why spend thousands of dollars on an engine that's worth $500?

With the exception of people like Racer x, who are competing in events that require a certain displacement.

[Racer x]

I love crazy projects. But reducing the stroke of an engine is not something that a person asking such questions can do. It's the price of custom made parts. I would guess 5000- 10000 dollar for a crank rods pistons and block plus a custom timing chain.

[ninjamunky85]

Sometimes the truth hurts.

[Falcor]

Not saying it isn't POSSIBLE, but you'll be breaking the bank doing it. A more realistic approach to get the power band you want would be the new ninja 300 engine or the 400 engine as mentioned above.

[ninjaryda]

Originally Posted by Racer x

Why not buy a 400 ninja?

Besides the fact that the engine is fairly new and only sold in Canada (for NA):

68.4 mm × 54.3 mm (2.69 in × 2.14 in)
Compression ratio 11:1
Power 32 kW (43 hp) @ 9,500 rpm
Torque 37 N·m (27 lbf·ft) 7,500 rpm

It's also another stroker engine. That, and I plan to pick up a used engine for cheapest I can find, and rebuild from there. Looking for a used/cheap 400r engine doesn't sound likely or worth it.

I love crazy projects. But reducing the stroke of an engine is not something that a person asking such questions can do. It's the price of custom made parts. I would guess 5000- 10000 dollar for a crank rods pistons and block plus a custom timing chain.

$5000-10000??? I've built/rebuilt many different combination of chevy engines over the years. My brother as well (he's got more cash for it). That's 8 pistons, 4 mains, 8 journals, 16 values/lobes, etc. Never spent anything close to that. Once, I spent $3200 on a build up but that included a brand new set of Victor Jr heads ($1600), a new carb ($400), and the 4 bolt main block itself ($300), parts+machine work (I assembled them myself to save on the cost). I can't imagine a simple 2 cylinder engine costing anywhere near $5000 to rebuild, even if custom. Last I looked (about 8 years ago), you could get custom SBC ground cams for $250 range and up, and that's more lobes than a 2 cylinder engine cam.

Taking the 650 or 500 engine for example, two pistons and two rods. I don't need a custom crank. And I've used other engine rods on different engines before (rods from a diesel recut to fit SBC chevy). As long as there's enough meat on the caps, you can mill the rod/cap and reborn a new whole (that and over sized rod bearings were also an option). As for pistons, I'm sure there's got to be options for sets that don't have the rod pin bored (i.e. allowing for custom stroke length and dwell times). They have that option for SBC and they weren't 3x the cost of non-custom pistons.

Whether this is for my current frame or not, is kind of irrelevant. I mean, now that I know a little more about the 500r (I really don't like the look of this bike) and 650r, simply buying either bike isn't going to get me what I want. I'm pretty much set on what type of engine that I want (revver/ rpm screamer). And building custom engine combinations is also a hobby.

I guess I'm limited to racing crowd for info (which I found in the past, they don't really like to give too many details) or trail and error/ on my own to figure this out.

[ninjaryda]

Ohh... f*cking derr. I forgot, I do need a new crank (stroke). That's what I wanted to ask, are the cranks swappable between the 250,400,500,650, etc?

[KawiKid860]

The Ninja 500 motor definitely isn't a torque based motor. It has nice midrange but the peak power is at 9k, red line is at 11. Might seem low to 250 riders but trust me the thing isn't a torque based motor. Also its going to be basically impossible to do anything like this on a 500 motor. Check out WWW.ex-500.com

[Racer x]

the parts for a chevy are mass produced. So cost is lower. Hand made one of a kind parts like cranks and rods are not cheep. I got two rods 800 dollars. Pistons are sets of four at 200 that is custom. Maybe you dont need them. But to stroke a motor you need to move the head closer to the crank. That means decking the block and a custom made cam chain.

You can do it and maybe it will be close to 5000 . But the motor has to be built by a professional motorcycle engine builder. They are not cheep. I don't mean to discourage you at all. I would like to do this to a motor. But it is so far out of my leak I never even considered it. Please if you can do it and show us what you do. We all love this sort of build.

[ninjaryda]

Is there anywhere, where I can find specs on the 250,400,500,650 cranks? Counter weight size, main and rod journal widths and thickness, etc? Or anyone that a crank out that they can measure?

Yeah, right now I'm just gathering info. I'm probably gonna pickup a cheap/used 250 engine to disassemble and get familiar with.

[bruce71198]

Now you've got me thinking....I have an EX500, a spare 08 250 and a spare frame for an 09 250. Let the games begin. Does any body have the weight specs of the 250 and 500 engine ? The rear engine mounting area looks close, the front will require some fab. I weigh 185lbs if the two engines are close in weight I think this could be an easy swap.

[MistahT]

Originally Posted by ninjamunky85

I think you should put a 250cc 2-stroke dirt bike motor in there. That way you'll save weight, and keep the peaky powerband. I don't remember what the redline is on the 500, but I know it's lower than the 250. Like 10 or 11k RPM.

Or alternatively, you could just sell your 250 and buy a 500. Used 500's go for prices not much higher than the 250. They also have a strong following, and are loved by their owners just as much as the 250. I like the 500 better than the 650 and it's tractor motor.

I never cared for the looks of the 500 though. My next bike will be a 300.

Agree with both of these statements! 2-stroke would be a good choice.

500 isn't too much bigger or heavier than the 250 and I've seen em for a grand. Are you taking on this project to make something because you can or just to make the 250 faster? First answer I support, second I don't.

If you want something that doesn't make a lot of low end torque but makes power up top (can't believe no one has said this yet) go I4. 600cc I4 don't make hardly any power until at least 6 or 7k, and the R6 motor from a generation or two back redlined at something like 16,000rpms.

[ninjamunky85]

Originally Posted by MistahT

If you want something that doesn't make a lot of low end torque but makes power up top (can't believe no one has said this yet) go I4. 600cc I4 don't make hardly any power until at least 6 or 7k, and the R6 motor from a generation or two back redlined at something like 16,000rpms.

600cc I4 is in a completely different world than anything we've been talking about. Putting one in a 250 frame would be CRaZy.!<,

[MistahT]

Originally Posted by ninjamunky85

600cc I4 is in a completely different world than anything we've been talking about. Putting one in a 250 frame would be CRaZy.!<,

Nah, someone put one in a Honda Ruckus, that was kinda crazy.

It's basically everything the OP was asking for.

[ninjamunky85]

link to a video of that?

Edit: nevermind I didn't see the pic at first.

[MistahT]

Originally Posted by ninjamunky85

link to a video of that?

Edit: nevermind I didn't see the pic at first.

Videos

http://www.youtube.com/watch?v=Hsa2qh8tZVc

burnout
http://www.youtube.com/watch?v=BIbAc6osmbE

PoV
http://www.youtube.com/watch?v=kC-bIrsBz6I

[ninjamunky85]

alrighty then.