450r Engine In A 400ex Frame?

[02045037]

Has anyone ever tried this? If so how easy is it to do? I have tried searching but dont get what I am looking for. I am looking to take a 400ex chassis and install a 450r engine.

[klutch]

i've seen 2 people that have done it on this site one being 440challenger if im not mistaken talk to him.

[Barrymaxx]

It would take most of the steps of a normal hybrid swap. Exhaust modifications, mounts, chain alignment, probly swingarm modification, and intake modification.

Also keep in mind making room for a rad and components. It shouldnt be to bad if you make a header that keeps tighter to the head.

Good luck. If I had the resources, I would like to do something like this.

[440challenger]

Yes i did it over a year ago,and just freshened the chassis up a week or so ago.
Are you using the quad or dirtbike motor?

["THE ShoP"]

do it you'll love it


<a href="http://s106.photobucket.com/albums/m271/JoeSaitta/?action=view&current=DSC00261.jpg" target="_blank"><img src="http://i106.photobucket.com/albums/m271/JoeSaitta/DSC00261.jpg" border="0" alt="Photobucket"></a>

[Ruby Soho]

is it easier to put the 450r quad motor in, or is it about the same as the crf?

how much didd you spend on buying the motor?

[TRXRacer1]

Is there any advantage to this swap over just buying a 450r? They seem to be getting pretty reasonable in the used market.

[02045037]

personally I like the feel of the 400ex better, maybe its just because i rode one forever. The power of the 450 is nice. I just figured, hey, why not combine the 2 into 1?

great handling with a powerful motor... why not. I love the way the 400ex handles so I think this would be a great idea

[440challenger]

the trx is a much easier swap then the crf.
I did it without any research , i just went for it .
Used all trx motor mounts.

Its nice, but if you dont have a really built up 400 chassis,or unless you got a killer deal on the motor,its not worth doing it in my opinion

[Ruby Soho]

Originally posted by 440challenger
the trx is a much easier swap then the crf.
I did it without any research , i just went for it .
Used all trx motor mounts.

Its nice, but if you dont have a really built up 400 chassis,or unless you got a killer deal on the motor,its not worth doing it in my opinion

do you have to do that crazy intake modification?

[gcart2]

wow i would like this. i race with alllllll 450's but i love the handling of mine. ebay time =))))

[440challenger]

No intake mod using the trx, but the carb barely fits. :eek2:

[Hondamaster5505]

i had an idea.

A yamaha yfz450 with the dirtbike 450 motor.

The dirtbikes make around 52 ponies stock while the yfz's put down about 38 ponies stock.. because the factories de-tune them for the quads.

SO after that and an exhaust and everything, you have a more powerful racing quad then what the pros are usin :eek2:

[440challenger]

Originally posted by Hondamaster5505
i had an idea.

A yamaha yfz450 with the dirtbike 450 motor.

The dirtbikes make around 52 ponies stock while the yfz's put down about 38 ponies stock.. because the factories de-tune them for the quads.

SO after that and an exhaust and everything, you have a more powerful racing quad then what the pros are usin :eek2:

Say what?? :confused:

yeah i'm still yet to figure out why the dirtbike motors are making more power it should be the other way to compensate for an ATV's weight

[born2ride14]

Originally posted by FoxHondaRider
yeah i'm still yet to figure out why the dirtbike motors are making more power it should be the other way to compensate for an ATV's weight

EXACTLY!

[Hondamaster5505]

Originally posted by FoxHondaRider
yeah i'm still yet to figure out why the dirtbike motors are making more power it should be the other way to compensate for an ATV's weight


x2

I dont understand these people.

I think its because more people get injured on atv's then dirtbikes so they have to de-tune the engines for insurance reasons..:rolleyes:

Thats why it would make a great hybrid. Piped 450 quads make like 45hp, so if you have a piped yzf450 engine in your bike its probaly around 56hp. Not to mention a higher compression piston, cam, porting. That would be one sick ace race bike!

[416exfreak]

Originally posted by Hondamaster5505
i had an idea.

A yamaha yfz450 with the dirtbike 450 motor.

The dirtbikes make around 52 ponies stock while the yfz's put down about 38 ponies stock.. because the factories de-tune them for the quads.

SO after that and an exhaust and everything, you have a more powerful racing quad then what the pros are usin :eek2:

What the hell are you smoking man. Its some good stuff is all I can say.

A pro's race quad puts out somewhere between 63 and 70 HP. Why do you think they so carefully maintain them and rebuild them so often. Those engines are grenades with the pins pulled.:ermm:

[garrettpen]

I was told the dirtbikes have the exhaust cam retarded 2 degrees from the factory while the quads do not.

[416exfreak]

hmmm.

Retarding the exhaust valve would allow the fuel and oxygen to stay in the chamber longer, and detonate fully.

That makes sense.:)

[416exfreak]

Originally posted by Hondamaster5505
x2

I dont understand these people.

I think its because more people get injured on atv's then dirtbikes so they have to de-tune the engines for insurance reasons..:rolleyes:

Thats why it would make a great hybrid. Piped 450 quads make like 45hp, so if you have a piped yzf450 engine in your bike its probaly around 56hp. Not to mention a higher compression piston, cam, porting. That would be one sick ace race bike!

I dont know that more people get hurt on Quads. I think its just that its more publicaly broadcast when someone gets hurt on a quad. And its usually some underage kid, with no helment, riding a quad that is way to big or fast for them.

You dont see an 8 year old on a CRF450R haulin *** through the neighborhood.:scary:

[Hondamaster5505]

Originally posted by 416exfreak
I dont know that more people get hurt on Quads. I think its just that its more publicaly broadcast when someone gets hurt on a quad. And its usually some underage kid, with no helment, riding a quad that is way to big or fast for them.

You dont see an 8 year old on a CRF450R haulin *** through the neighborhood.:scary:

lmao.

[jesseweaver]

Originally posted by 416exfreak
What the hell are you smoking man. Its some good stuff is all I can say.

A pro's race quad puts out somewhere between 63 and 70 HP. Why do you think they so carefully maintain them and rebuild them so often. Those engines are grenades with the pins pulled.:ermm:

so what do you think has more horsepower, RC's RMZ450 or any of the suzuki guys--gust, wimmer, or weinens race quads? the pro bikes are gonna have more power. same goes for stock im sure

[Hondamaster5505]

Originally posted by jesseweaver
so what do you think has more horsepower, RC's RMZ450 or any of the suzuki guys--gust, wimmer, or weinens race quads? the pro bikes are gonna have more power. same goes for stock im sure

thank you;)

If the pro quads are putting out 63-70hp im sure the pro bikes are putting out more!

And why do you think most people use dirtbike engines in atv's instead of other atv engines? Because the dirtbike engines are stronger!

[250x_kyle]

realy the yfz can easily be moddfied to the power of the yzf motor. the Cam mod for the yfz set the yfz timing to the yzf motor timing. and its a free mod if you have acess to a few toold and trust urself working on motors. the yzf motor makes around 48 hp as to where the stock yfz power is about 10 hp less. realy your going to waist your time swaping the motor when it can be modded out to the same power for damn near free if you know what your doing. as far as the 450r in a 400ex id say go for it i love the power of my friends 450r

[TheNewn]

Originally posted by Hondamaster5505
i had an idea.

A yamaha yfz450 with the dirtbike 450 motor.

The dirtbikes make around 52 ponies stock while the yfz's put down about 38 ponies stock.. because the factories de-tune them for the quads.

SO after that and an exhaust and everything, you have a more powerful racing quad then what the pros are usin :eek2:

Jesus you must be high. You're taking two dyno numbers and comparing them like that...for one, the quad motor has to move a lot more on a quad chassis than a dirt bike motor has to on a dirt bike chassis...2 wheels vs 1 of course the quad is going to dyno less by that alone.

Also, i personally think you have an inflated HP number on that bike, and a slightly low estimate of the quads HP. In reality, i'd bet that both motors are a lot closer together than that. especially after something as simple as a cam mod.

[Hondamaster5505]

i know for a fact that they de-tune them for quads.

And second of all, i got the number of the dirtbike out of i think transworld motorcross or somethin like that.

38 is a round about number for the yfz.

All im sayin is that the quad engines ARE de-tuned from the dirtbikes.

Im clean, drugs are gross and nasty! :rolleyes: lmao

[TheNewn]

Sure they're detuned, but not NEARLY enough to make it worth the swap.

i believe the HP on a YFZ now is like 40HP, and here's a dyno on the 2003 (which i believe is the most bad *** YZF450 motor) and it shows 49 HP.

http://photos.motorcycle-usa.com/450_hp_dyno.jpg

Take into account that the quad has to turn two wheels, and an axle. I woudl think that the YFZ only has a couple to a few less HP than the YZ. Hardly enough to make it worth a swap. And then you do the Cam mod and such and you can *EASILY* make the YFZ put out as much power as the YZ motor.

*IF* they were dyno'ed in the same chassis.

[02045037]

how many people are going to try this? How many of you already have? I am gonna try I guess, I just need to start with getting a 450 engine, then the mounts, rad, wiring, etc. This is gonna be tough, I have never even tore down my 400ex, Im scared to take it apart to even get the frame painted. I hope it will work ok for me.

[440challenger]

honestly, if your scared to take your ex apart for paint, then this is not a project you want to take on.

You need to weld all new motor mounts in. Oil cooler and rad mounts, Overflow and coil mounts . raise the tank a bit, hog out the intake boot on the air box side, make sure chain alignment is dead on, gusset the frame becuase it will indeed crack!!

If you cannot do the work yourself, (welding,fab work) its going to cost you an arm and a leg.

I dont want to steer you away, but i've done it and it gets expensive,even doing it yourself.

[250x_kyle]

if you havent torn your quad down do not do it. if you do not have acess to cutting torches welders well basically a fab shop i wouldnt attempt it. im going to put a yzf motor in my 400 chassis soon. there is alot of work involved. you have to be 100 percent sure that the chain is aligned. the motor has to have the right tilt angle. you have to have a radiator and a custom exhaust system to clear the frame. you will need a differnt intake system because its not ment for the specific quad. only thing about the 450r motor that good is the kick is forward so you wouldnt have to make a kickstart extention.