CRF 450 swap a good idea?

[Cole]

I am wondering if dropping in a CRF 450 motor would be a good thing to do? Is it more powerful than the 400ex motor? Will there be alot of upkeep down the road. Are there companies making aftermarket parts compatiable with the450 motor? Does this engine bolt up easy to the 400ex frame? Or, any other info you may have.

Thanks

[hondaforlife]

The 2003 CRF 450 has 55 horsepower, the 400EX makes about 27.

[Cole]

What all does the swap consist of? (Parts and Labor)Why dont more people do it I wonder?

[wheeltrax]

It is well worth it from ppl i have talked to. I dont know whats involved. I know someone on here knows more bout it.

[ESR250R]

Originally posted by hondaforlife
The 2003 CRF 450 has 55 horsepower, the 400EX makes about 27.

i know the 27 is measured at the rear wheels on the 400ex, but what about the 55? was that number taken from the rear wheels of a quad. if not it would probably be more like 45 (which is still alot more but please compare numbers from the same point).

[OutlawEX]

You would have to do alot of modding to ur frame,like getting mounts for the radiator to fit..Also u would prolly need some custom front motor mounts made up,and also u may need a kick start exstension,and for sure u would need to re-inforce ur frame..

[Guy400]

Originally posted by ESR250R
i know the 27 is measured at the rear wheels on the 400ex, but what about the 55? was that number taken from the rear wheels of a quad. if not it would probably be more like 45 (which is still alot more but please compare numbers from the same point). I thought that 55hp was measured at the crank on a dirtbike. You can bet that on a quad spinning an axle and 2 tires that the drivetrain loss will be much greater.

Also, I don't know how soon you need it but you may want to hold off for this summer. You'd hate to put a lot of money into a custom conversion only to have Honda release the same quad later this year. I've been hearing more and more rumors of a new Honda from inside sources.

[NTPRacing#19]

the crf conversion for a 400ex frame is good from what i hear. i might be doing after this season when i get some cash for it.

[honda400exrider]

im pretty sure the motor is like 4500 or something too:eek2: thats like buying another 400 cost wise:devil

but if u got deep pockets, im sure you will be glad u made the switch...

[ridered03]

i would go for it!!!!!!!!

[d-14 rider 27]

dude, aside from suspension, its the best money me and the old man ever spent. its fairly easy to do, if you got a good welder, im redoing my conversion on another frame right now, i didnt like how i leaned the motor forward to make room for air intake, too much wear on chain slide/swingarm :eek: and i got a bigger radiator now. ill start takin pictures soon. and if you like, when your ready, shoot me a pm and i can walk you thru it. but ill make a rough list, so you can figure out what your gettin into.

1. AFTERMARKET radiator, 450 runs hot, stock in a bike itll boil water in less than 2 minutes sittin there idling.
2. kicker extension, mxbubs made one by using another splined knuckle and a bushing welded between, and i give him props for comin up with that plan, i still dont mind payin 200 for a ecatv, then i know for sure its there to stay.
3. gonna have to rig something up for airboot, ill tell you what i did in a pm.
4. depending on swinger your gonna have to do some grinding on the front of it to get the motor to the left and make new bearing sleeves.
5. another certain frame mod has to be done, but ill let you know that in a pm. but its not hard.
6. exhaust, i cut the stock header, and had the muffler shop bend me a mid pipe to my sparks x-6 silencer. baldwin makes these, and i think gt thunder makes a mid pipe or a full exhaust.

[NTPRacing#19]

d-14 was the reason you tilted it to far forward so you can get a headstay bolt in? ive heard that eastcoastatv doesnt put headstay bolts on in their crf450 400ex conversions becuase the motor is to tall for the 400ex frame. am i correct?

[Cole]

D-14, Thanks for the info. There looks to be alot of work involved. I am really wanting a bike to contend with the raptors and the cannondales in my local circut. The Cannondales are 1 and 2 in the points. Next year I want to be ready for'em. I wish that I could set up my 400ex motor to do this, but I dont know if its possible. Looks like Im gonna have to switch out engines to the 450. PM me the info that I will need for the swap if you will.

Thanks a million.
Cole

[blastersrule]

http://www.servicehonda.com/engines.htm the best place to buy a new engine:eek2:

[d-14 rider 27]

the reason i had it forward was so i had more room to play with the intake, but i got a different boot now so its cool. you definatly need to run a head stay in a ex chassis without it, (i havent witnessed it) but i bet it would fold the frame in half, east coast's conversion is a hack job. for my head stay i just used the stock head stay plates off the bike, looks trick that way too. im gonna be held up on assembly for a few more days because i have no place to paint it becuae my trailer is in the barn gettin worked on and i dont got a 32 ft tarp. ill find a place to do it, my shocks should be here sometime next week. later

[d-14 rider 27]

i forgot to say, the 450 is actually shorter than a ex motor. very compact.

[BigThumper33]

I can't wait till college is over......just 4 more years and I'll finally have enough money to do a project like this!!!

[NTPRacing#19]

oh thanks d14 i just wanted to clear that up in my head.

[roostu]

Originally posted by BigThumper33
I can't wait till college is over......just 4 more years and I'll finally have enough money to do a project like this!!!

Just Drop out!!

J/K :D

~Roost-U

[KandK952]

I have half of a bike paid for that I am going to be using for the conversion. I will be using the stock frame for now so I will post on how it was converting it. Eventually I will get a frame for the CRF.

A good thing to do is buy a used bike for like 4-5 grand, use the motor, carb, electrical and header and sell the rest of the bike. (part it out or sell it whole)

[DirtDiggler]

I think if you buy all the parts East Coast ATV will do the conversion for $995.

http://www.eastcoastatv.com/400exyz426conversion.htm

I don't know where you live since I didn't look under your icon but if your handy with welding a lot of guys do it on their own.

I heard 55hp is at the crank

[d-14 rider 27]

east coast conversions suck
1. no headstay!
2. looks like a monkey welded it
3. too damn expensive for something not even done right

they just cut too many corners.
I'll do conversions for half that if you want to send me your parts and it will have a headstay, better motor mounts, all tig welded, just a thought.

[DirtDiggler]

sounds killer! I have never seen an East Coast conversion I just found it on their web site.

[trx400ex]

i think it would be neat to keep the bike and just swap engines whenever...thats what i hope ta do if i get the $$ together

[NTPRacing#19]

i would do my own conversion. ive heard that a 250r frame is perf for a crf450 conversion cause all you gotta do is lower a mount and get the right front motor mounts and it drops right in

[d-14 rider 27]

my re-conversion is almost done, finished up mounting radiator and scoops tonight, im gonna finish some welds and gussets tomorrow, then sandblast it, and try to find a place to paint it, or somewhere where i can get it pc'ed in a day, then ill start taking pictures as i assemble it, im much happier with the way it turned out the second time. if any of you guys doin conversions need help figuring something out, or have any questions, pm me, i got this down to a science. later

[Mxbubs]

Originally posted by d-14 rider 27
east coast conversions suck
1. no headstay!
2. looks like a monkey welded it
3. too damn expensive for something not even done right

they just cut too many corners.
I'll do conversions for half that if you want to send me your parts and it will have a headstay, better motor mounts, all tig welded, just a thought.


Hey, didnt I say that already?:D

Just kidding.....but if I didnt, I will echo it.

[Sick0]

Eastcoast do use a top head stay. I was looking through some of there pics and you can see they do use one.

[d-14 rider 27]

nope. no headstay

[NTPRacing#19]

yea def called and asked about that and def no headstay.

[DirtDiggler]

the bastids

[d-14 rider 27]

mine is done now, gotta take back apart and get a few more welds done and get it pc'ed, then build my new subframe, shocks should be here next week, snd im gonna try my damndest to get it done in time for the first d-14 race at log road on the 8th i think, so ill get pics as i put it together. ya'll are gonna ***** when ya see it not to brag, but i promise :eek:

[DirtDiggler]

I'm pshyched to see it man. Arens is making a kit to bolt a crf motor into there new 400ex chassis. He said everything on the 400ex will bolt up to his frame no problem. He said the kit doesn't require any cutting or welding so I'm thinking it will work with a stock ex frame as well. I don't know what the kit costs but Arens doesn't over price stuff.

[TEAMPHIL]

Theres several kits to swap in a crf450 motor but very expensive. We've dyno tested a stock trx400 ex, it had 27.2 to the rear wheels. Our crf450 had 56.4 to the rear wheel. Instead of swapping in a motor, I would wait for TRX450R to come out from Honda. Rumor has it, it is way cool and way fast. Honda has the biggest research and development departments there is. It will be worth the wait.

[Mxbubs]

Originally posted by NTPRacing#19
yea def called and asked about that and def no headstay.


Their conversions do not use a head stay. They claim you dont need one....(haha)

However, their aftermarket frames they use do have them.....

[MojaveKing]

it would be Killer! :D


i would do my own conversion. ive heard that a 250r frame is perf for a crf450 conversion cause all you gotta do is lower a mount and get the right front motor mounts and it drops right in

I would and want to do the same thing......i have seen the frames...@ like Lonestar..yea thats it......but really would it drop right it to a 250r frame???
help any1....

[mxracer08]

the 450 has 49 horse at the wheels and you don't really have to do a lot of modding to the frame. the main reason a lot of people don't do this is because the motor is $3800 from honda

[d-14 rider 27]

what do you mean it dont require modding? you have to move the upper frame tube to the outside, intake dont work out worth a *****, the stock rear piggyback shock will hit a small casting on the cases, only thing thats easier about putting in a 400ex instead of a yz motor in a 400 is the oil lines. if youve never done a conversion dont start talkin how easy it is, half way thru the project i was wishin i did a 426 instead.

[KandK952]

d-14... what upper frame tube do you have to move, and why? I am doing 2 conversions, one will be next weekend and I think it would be good to know. I think I have a pretty good idea on what needs to be done except for what you just mentioned.

[d-14 rider 27]

the top left frame tube has to be moved so its flush with the outside of frame otherwise the valve cover will be against it. youll see what i mean when you go to do it. also, you gotta grind on the front of the swingarm in order to get the motor moved over. if your runnin stock rear shock, you gotta grind a lil bit off the right side of the can, and a lil off one of the clutch cover bolt castings. the intake is a b!tch to mess with, and just make damn sure you use a headstay, or youll fold that frame in half. if you got any other questions, shoot me a pm and ill help you out. oh and the bushings that are in the cases for the pivot bolt, instead of makin a sleeve or new bushings, drill out the frame, and get a kawazuki pivot bolt, check into this, im pretty sure its the same o.d. as the bike, but i dont know what youd have to do for bearings then because i dont know if their interchangeable, might just be easier goin the traditional route, just a thought tho.

[d-14 rider 27]

btw mxracer08 sorry if that sounded like a flame, i didnt intend for it to be, i was just sayin that its not as easy as you think if you wanna do it right.

[nyceguy01]

IT SEEMS LIKE EVERYBODYS MISSING THE OBVIOUS CONVERSION.
I PUT A 250 R WITH AN ESR 310 TOPEND ON IT WITH SOME PORTING ETC.. IT EASILY SMOKES RAPTORS AND WILL RUN WITH ALL BUT THE STROKER SHEES. I INSTALLED THE MOTOR IN 6 HOURS AND IT IS DEFINITALY NOT A HACK JOB. I KNOW MOST OF YOU GUYS ARE THUMPER LOVERS BUT FOR THE COST VS THE RETURN IN MY OPINION THIS IS THE ONLY WAY TO GO. KEEP IN MIND OPINIONS ARE LIKE A**HOLES-EVERYBODYS GOT ONE AND THIER ALL A LITTLE DIFFERENT

[d-14 rider 27]

damn dude, i can hear the text just fine no need for caps :p . but why would you put a r motor in a ex, other than you may like the handling, and cheap parts..... well i guess i just answered my own question, but i woulda kept it in a r frame. their stronger than ex frames, i just cant ride the geometry.

[nyceguy01]

I bought a 400 before i realized how horribly UNDERPOWERED they ALL are. So i had the bike. I dont want to be seen riding a 15 year old bike. You can get a 250 r motor (out of an ATC)for next to nothing. The suspension , well I can go on all night.

[d-14 rider 27]

post pic of that bad boy

[sabertooth]

I am putting an xr650 engine in one of my 400ex's. Seems like a simpler mod with similar power and far less expensive of an engine to buy. A dealer near me quoted me $2700 out the door for the xr650 engine and $4550 out the door for the crf450. I am thinking of entering the baja in a couple years and am building this quad for that. Most of the 400ex's that enter that that have had an engine switch have switched to the xr650. I have also heard that the crf450 carries its weight high because of the radiator. The xr650 is heavier towards the bottom of the engine. On a dirtbike this doesn't matter too much. The result on a quad would be more pronounced. You would feel like you're on a raptor. Also, this will depend on the type of riding you do, mx or heavy trail riding...crf450. Dunes or more open riding...xr650.

[forum]

Well first of all i'd like to say that it invloves alot of work unless you get someone else to do it and they will over charge you. Next you need to be able to weld and have some metal fabrication skills, even if you buy all the little parts from somone like baldwin, ecatv, (which they will rape you on the price if you do) there still will be some metal fab work you will need to do. But if you do it. It will be much better then the ex ebgine. NO ONE i MEan no one can build a 400ex engine to produce as much HP as a 426 or 450 engine and still be realiable enough for MX. The crf engines powerpand is more like the 400ex, easy and smooth with lots of tourgque just alot more of it everyware.while the 426 is more like a 2 stroke . the bottom end isn't as powerfull as the crf but it has more Hp at the top. this said the 426 will wear you out faster like a 2 stroke but not quite. I used a 426 cause i found a good deal i couldn't pass up. Both engines are 10 times better then the ex engine in more ways then one. 1. way more power, especialy stock for stock 2. Lighter, by more then 30 pounds! 3. Liquid cooled so it wont over heat when its modded and racing in hot conditions. THe downsides are kickstarting and....the work it takes to do. But when your racing it don't matter how you start it. Unless you stall it. But that rarely happens if you know what your doing

[Mxbubs]

Hey D, how bout them pics yet man?

[d-14 rider 27]

if your talkin about me, i should get out there and get some pics. ill have some monday.

[Mxbubs]

Well get em up!

We are dying to see!

[400exdad]

Take the time you think it will take you to do it... and double it.
Take the money you think it will cost you to do it... and double it.
It still won't have an electric starter. Be patient and wait. You'll get close to what you want... for less. Use the rest of the cash to make it EXACTLY what you want. JMHO :)

[d-14 rider 27]

its gonna be later monday night i gotta clean her all up and fix shifter (i bent it when i decided to part with the quad on a jump called killer) :eek:

[d-14 rider 27]

heres one that turned out somewhat decent

[d-14 rider 27]

and heres one that got cut off cuz im not good with a digital camera. prolly dont help that i got it from savin all my marlboro miles:p

[d-14 rider 27]

at least you can see the conversion part of that last one. none of the others turned out. ill get some more when the suns out later this week.