416 vs 426 and hotcame stage 1 vs two.

[mitchconley]

Tomorrow I'm going to be deciding what I want to do for my next step in my ex build. I want to do a 416 or 426 but im not sure if I want to spent the money to get a cam. Which bore would you fourm members recommend and what cam would you recommend running with it?

[mitchconley]

Im going to be running 10:1 compression and 93 octane pump gas

[leakyvoodoo]

i run a 416 12.5.1,sparks exhust,cam and cdi. i keep up with my boys 450r

[honda400ex2003]

stage 1 for lots of low and mid, stage 2 for more top and mid.

both are great setups! I really like mine.

probably a stage 2 with a 400 carb, lid off, and would be a great recommendation for you to run if you want a mid and top machine.

if you want an all around gen riding great machine, 6 degree, 400 carb stage 1.


steve

[honda400ex2003]

also what do you want to do with it first?

that is the main thing. mx, dunes, woods, trails?

[Thumpin440ex]

416 416 440, they all can run better or worse then one another.. just depends on the set up. I have a stg 3 cam, did the gears.. Bike was a beast, would walk piped 450's all day from about 3rd on up.. I have since dropped a front tooth off the front, the bike is still a beast, the trails is just about rite.. 4th gear wheelies, thats no bs.. However now seeing the majority of riding I do, i would have prob went with a stg 2 cam, for the lower and mid, moreso then top.. I have never rode a stg 2 cam bike or 1 so I do not know how the power actually feels..

John

[mitchconley]

okay well im ordering the parts later. Im probably going to end up flipping a coil over it haha. Im going either 416 with no cam and basically nothing else or a 426 with a stage 2 and drop a tooth in the front. I dont do anything but woods riding and I want to keep my air filter lid.

[CJM]

Bore size is not nearly as important as compression. A 426 is only 10ccs more displacement than a 416, it also creates more heat because the cylinder is now thinner.

Do a 416 and do a 10:1, 10.5:1 or 11:1 compression piston. Thats where your gonna get the power.

[honda400ex2003]

stage 1, 10:1 416, lid on, with a 6 degree key in it. :D great woods machine with 15/38 gearing even more insane with a 14/38.

steve

yea its sounds like you're gonna do nothing or all with a 416 and nothing else vs a 426 cam and everything. You will not b disappointed with an 11:1 416 with a stage 2 hotcam.do yourself a huge favor though and find a local race shop (car dirt track) or something similar. Check around with ur local motorheads and find the right guy and have him clean up the intake ports/grind and re seat the all the valves and get some kibblewhite heavy duty valve springs and have him install them while its there and torn apart. It will save major headaches later and for what little more you invest the end result will be much more significant. Mine has low end grunt and pulls to the moon up top.If ur bottom end is too high for you or your trails drop one tooth on the front sprocket.with all that work which believe me its all necessary to avoid having a weak link in the system a good hi rev cdi will complete the package assuming u already have an aftermarket exhaust. From this point on you should also get yourself some 25lb dumbells and do forearm curls all day long and with any luck you'll be able to hang on to the beast for a full day of riding.

[honda400ex2003]

theres no need for hd valve springs with a hotcam nor a cdi box. theres no reason to waste the money on it for teh extra 1000 rpms, these motors dont make enough power to make it worth it. shift sooner if you are hitting the limiter.

agreed on a nice p&p though with a valve lap.

steve

Originally posted by honda400ex2003
theres no need for hd valve springs with a hotcam nor a cdi box. theres no reason to waste the money on it for teh extra 1000 rpms, these motors dont make enough power to make it worth it. shift sooner if you are hitting the limiter.

agreed on a nice p&p though with a valve lap.

steve

10,000 rpm times i dont know i get a couple hundred hours of saddle time a year.....yea $100 of insurance with all that motor work is more than worth it to me.anyine who's seen what happens when good springs go bad will agree. Do it right and forget it or heck i can get you a frag grenade for $250 attach it to your spark plug wire via the pin and go for a ride.it will give u similar results and u wont have to spend all that time wondering when it will happen. I forgot while you're in there get a crf 450 cam chain....way cheaper than a brand "x" heavy duty chain.Actually they probly are brand "x's" heavy duty chain just without their name on it. Bottom line bro don't skimp or cut corners. Getting heavy duty springs has absolutely nothing to do with power output and everything to do with reliability.ckeck the sig and you might find i know a little about those things of which i speak.

[trxPOWER]

i dont think there is anything wrong with the stock valve springs, i just tore mine down and found out its got a stage 2 hc in it, and ive had it a while with no troubles whatsoever.

[honda400ex2003]

hotcams doesnt recommend using hd valve springs either. i guess that the hundreds of people running them on this site with no issues should tear their heads apart and put them in. they are not hardfaced to need any hardfaced rockers or anything nor are they radical enough to need hd springs. maybe the stage 3 is but the rest arent for sure, and i wouldnt even recommend them on a stage 3.

steve

Sorry mayb u guys dont get the saddle time in that some other people do. Ill torch a $100 bill for peace of mind. No one has to do anything its what i chose to do beacuse like i said up to 10,00 rpms multiplied by lets say ur average rider atleast in my circle gets 250 plus hours a year. Thats 150,000,000. Dont ride that hard or that often lets go 6,000 rpm multiplied by 100 hours a year we get 36,000,000. Multiplied by how many years have the stockers been in....and at what point do u actually plan on changing them in the future......how many years???..... yea keep multiplying. If you're on a budget go with bazookas instead of razrs but dont skimp on cheap insurance for your poweplant. Its only my 3rd post but i've been a member with a different name on here since like 02 or 03. Forget this clown telling u its not necessary,he should be banned for giving somone crap info,wish mickey dunlap would pipe up here soon.
While the machinist is in there have him grind and re seat those valves to extract max power out of the rest of the work thats done.the more crisp those valves snap open and closed the more crisp ur throttle response. it wont b much and nothing is necessary but its better than sitting over a broken machine regretting not doing it cuz joe schmo says its not necessary and doesnt have to b done. This is my second 400 build....i listened to these joe schmo u dont have to do it its to expensive types before. That motor is on my shop floor "grenaded" out. Clutch basket exploded,no fingers left,and the sparks heavy duty clutch kit looks like literally a bomb went off inside it.Whatever u do dont listen to the dude that has all sorts of cam and big bore piston while rocking a timing advance key....how much "power" since that's your concern, are u getting out of that key????LOL

[mitchconley]

Im sure your wheeler will run for 100 years because you have done everything you can to it to make it bullet proof and I wish I could do the same to mine but I don't have the time or money for all of that. If I do a stage 2 Hotcam lets say would a timing chain be something that would need to be done? I really dont even know how aftermarket timing chains change anything, can somebody enlighten me?

[CJM]

Timing chain should be for a 2002 CRF450, it will fit no problems and is thicker and stronger than stock, not to mention cheaper inprice.

You guys can build it anyway you want. I and many others have ZERO issues with the stock valve springs and stock valves. Sure I reground them and checked the springs but for not being opened since it was built till about 2008 it was fine and still is fine.

A CDI is a personal preference, but that extra 1000rpm isnt gonna be felt to be worth it.

PAxcThumper: I find you highly condescending and nasty. Whomever you were previously you should tell us, Im sure you were a troll before and will continue to be today. Sorry your 400EX blew, but apparently those who have a clue's engines are still together no problem-including mine-which ir die easily 500+ hours a year. Still no problems since I built it and its been oh 3 years now.. So whats that like approx 1500+ hours....

If all your going to do is argue then your advice is not welcome here.

you know what man skip the springs skip the chain put the cam in good luck. a chain is only as strong as its weakest link your motor is no different. you want the best upgrade for you right now,get some suspension it will make you faster than any mod you can do at this point. this thread is reminding me of y i stopped using this site some 5 years ago,some things never change. im not trying to argue,this site is so people that have done it can help/inform the people who haven't. cjm check ur pm box.

[Thumpin]

I like the 416 I built and got most all my advice off here and from the sponsor of this website, C&D Racing. He got me my engine parts and did my machine work on the cylinder and head. Lasted over 3yrs going on 4 with no problems!

Call Colby and he will lead you in the right direction, he's very competitive on prices and machine work. He builds several 400ex engines a year and knows all the in's and out's!

[2001400exrida]

i just did a 426 rebuild and i left my valves.

replaced the valve seals, took the bottom of the valves to the grinding wheel and slapped them back in there with the stock springs.

[CJM]

To regrind the valves-if they arent to bad:
1. Remove the springs and seals
2. Get valve lapping compound, spread it on the valve and put the valve back in the head.
3. Get portable drill and grind valves, making sure to push the valve up and out of the head slightly after every 5-7 secs. Do this for 30 secs to each valve.
4. Clean everything off very well with break cleen and put all back together.
5. Grind is perfect.

Its an old school engine builders trick and works wonders so long as the valves arent horrible.

[hocman123]

Originally posted by 2001400exrida
i just did a 426 rebuild and i left my valves.

replaced the valve seals, took the bottom of the valves to the grinding wheel and slapped them back in there with the stock springs.

u shouldn't take the valves to a grinding wheel u shouild get lapping compound put it on the edge put the valves and put it in the head were they will be and put the other end in a drill and move it back and forth many times that way both ends get a good cut and good cross hact patern. is not u could have problems with the valves leaking

[2001400exrida]

I have heard of the drill trick and seen it on youtube. I'm afraid of doing that.

the proper lapping tool doesn't allow you to grind very hard or fast which is very important.

you could eat it up good by chucking the stem to the drill, it just sounds too rough.

also, hocman the grinding wheel was just fine bro. I was referring to grinding off all the carbon on the bottom of my valves. I took that to the grinding wheel.

i lapped the valves with the proper suction cup tool.

[hocman123]

no a metal chuck doesn't hurt the end at all. the chucks are all smoth and do no damage.

also if u take it to a grinder if u do one side more then another it could get out of round vary easy

edit: oops ok u i also use a grinding wheel for the carbon its the only way to do that my bad

[2001400exrida]

all i was doing with the grinder was taking the excess carbon off the bottom of the valves.

i'm not worried about the valve stem i'm saying that the drill power could easily tear it up.

the hand lapping tool is much more gentle.

[CJM]

Multiple times over the years no issues. Chucking it in a drill wont do any harm, your not doing it very hard-what it does is speed up the handlap process and give you a better overall grind.

The machines that a shop would use do the same exact thing.

[hocman123]

yea its defenatly more gentle of a method but i like the drill b/c it is a lot faster and easier to do btu is a little harder on things but i have done it that way a few times and have yet to have a problem

[2001400exrida]

i'll take your word for it fellas.

but i'll stick to the manual on this one :cool:

[2001400exrida]

Originally posted by CJM
Multiple times over the years no issues. Chucking it in a drill wont do any harm, your not doing it very hard-what it does is speed up the handlap process and give you a better overall grind.

The machines that a shop would use do the same exact thing.

i would not go so far as to say it gives it a BETTER overall grind.

the reason the hand lap works better than the drill method is because it cross grinds much faster and more effectively.

your drill can't do what the hand tool method does. Hand lap tool goes left and right very fast like starting a fire with a stick.

the drill goes one direction, then you click it and then it goes the other direction, then you click it, then it goes back one direction.......

you're doing too much grinding in one direction instead of a nice even lap with the hand tool.

say what you will but the best lap will come from that lapping tool.

plus you can't even see what you're doing when you use the drill because you're coming from the top side of the head. At least with the lap tool you can very easily see how the progress is going, or reapply compound much easier.