400EX Cams: Which One and Why?

[04'400ex'er]

I am looking at putting a cam in my EX. I want to know what goes into putting one in and basically how you do it. Also, As soon as I need a ring job I am going to be doing a 416 motor, but that might be a year later. Will it be ok if I put in a cam now and then do a rebuild later? Or will I need to replace the cam when I do the rebuild? Will I lose any reliability? And What is the best performing cam on the market for the 400? I have herd good things about WEB cams and Sparks cams, not much on Hot Cams. How is the power increase? Compared to my HMF? I just basically need these questions answered to make my decision. Thanks for the help.

[mx400]

Originally posted by 04'400ex'er
[B]I am looking at putting a cam in my EX. I want to know what goes into putting one in and basically how you do it. Also, As soon as I need a ring job I am going to be doing a 416 motor, but that might be a year later. Will it be ok if I put in a cam now and then do a rebuild later?

yes it will be ok and then do a rebuild later


Or will I need to replace the cam when I do the rebuild?

you can do it either way


Will I lose any reliability?

no you shouldn't


And What is the best performing cam on the market for the 400?

different strokes for different folks but I prefer hot cams.


I have herd good things about WEB cams and Sparks cams, not much on Hot Cams. How is the power increase?

Everyone will give you personal preference and then there are some who will give you an opinion based on what they have heard not on what they have used. I have used the hot cams and sparks cams and the Stage 3 hotcams cam is almost identical to the Sparks cam. Both are wonderful cams, with the Sparks cam being a little bit more aggresive(few degrees) but not so much that you will notice unless you are running your bike hard.



Compared to my HMF?

there is no comparision. the cam will put way more power down than any exhaust.

[DaleJrFan]

I just installed a stg 2 hotcam and a LRD full exaust and the combo rips!! I dont know about the other cams but the hotcam was easy to install and I plan on doing the same, a rebuild later this summer. right now I have a stock piston and I can tell a noticeable power gain with the full system and cam combo.

[04'400ex'er]

I didn't know that hotcams made a stage 3 cam. I take it it is a hotter cam than the stage one and two? If the sparks cam is hotter than the stage 3 then I think i might go with that. Where is the power at on the cams? Is it most noticleable at mid-top power? I just want to get all my options down on the different cams on the market and which are the most powerful. Also, what is the average installation time on a cam?

[Cody_300ex]

Web makes very good products. A friend of mine races dirtbikes professionaly in flattrack. When he dosent have his engine builder build him cams (some guy out of wisconsion) he runs Web. He said Hotcams are worthless, but are OK for a rec rider. For raceing they are just not up to parr with Web. I think if you get a cam, go all balls with it and get the most radical one or near atleast. JMO

[Tattooed Trash]

TC Racing makes a great cam for the 400ex- I've been running one for the past 3 years now- makes great power all through

[wheeltrax]

i believe the new stage 3 is the old stage 2, and the stage 2 is a new grind. I have the stage 2 and i like it.

[mx400]

yes you are correct. the old stage 2 is now called the stage 3 and hotcams has a new grind for stage 2 which is in between the old stage 2 and the old/current stage 1.

i totaly spaced TC's mx cam. That cam is great. I have never isntalled one or owned an engine w/ it installed but have ridden a few quads w/ his mx grind cam and it rips.

for my new race motor I will be goign Sparks mx or TC mx. I'm still waiting to get exact durations back from both Sparks and TC and then I will decide.

[cals400ex]

i run the TC mx cam and it does rip at midrange. i need more top end power though. my sparks pipe wants to rev well past the stock rev limit. the cam will go that far but it needs to go farther, i think. if sparks or tc tells you the lift and duration i would be surprised. if they do, i would love to know.

[Dave400ex]

I run the TC XC Cam and like it a lot also. I think the biggest thing you need to do, is ask yourself where you want more power.

Also I doubt TC or Sparks will give any #'s on their cams, if people figured them out they could just have Web make them.

[04'400ex'er]

well I want tons of mid range and more top end. everybody knows the 400EX has plenty of torque. I would like to know which of TC or Sparks cams makes the most power. Does WEB make a cam that compares to those or overpowers them? Are they more powerful than the HotCam stage 2? Are there any other decent companies that make powerful cams? Thanks for all the help guys. And to mx400 if you get the exact durations from either TC or Sparks please let me know.

[Dave400ex]

Well for mid-top you would want the TC MX Cam.

[04'400ex'er]

Does anyone know the grinds on the hotcams, WEB, TC Mx, or Sparks Mx?

[cals400ex]

check this thread out. i posted a few of the cams numbers in the middle of this thread.

http://www.exriders.com/vbb/showthread.php?threadid=153137


you will find a few more cam grinds in the frequently asked forum on this site.

[04'400ex'er]

Originally posted by cals400ex
check this thread out. i posted a few of the cams numbers in the middle of this thread.

http://www.exriders.com/vbb/showthread.php?threadid=153137


you will find a few more cam grinds in the frequently asked forum on this site. Thanks alot cals. You never fail to let me down.

[MIKE400EX]

Thanks alot cals. You never fail to let me down.:huh

[04'400ex'er]

Originally posted by MIKE400EX
Thanks alot cals. You never fail to let me down.:huh Dude you are cool. but i got an idea. why don't you take your stupid ***** coments to another thread because no one here wants to hear them kid.

[MIKE400EX]

What's the matter "04'400ex'er", no sense of humor?

Kid?..... Thanks for the compliment! My Grand Kids are probably older than you, and at least they can use the SEARCH button.

[04'400ex'er]

Originally posted by MIKE400EX
What's the matter "04'400ex'er", no sense of humor?

Kid?..... Thanks for the compliment! My Grand Kids are probably older than you, and at least they can use the SEARCH button. Well I hope you raise your grand kids up to have the class you do And am I not entitled to ask a simple question on a thread that I started? Your grandkids can use the search button? Thanks for pointing that one out. Anyway, Im done arguing with you.. :rolleyes:

[mx400]

why does every thread turn into a pissin contest?

[wilkin250r]

Ok, seriously. 04'400ex'er, I think you're over-reacting a little bit. You had a little brain-fart, somebody called you on it, and now you're blowing it WAY out of proportion. It was just a little joke, you don't need to climb to the top of a belltower with a sniper rifle, okay...

[MIKE400EX]

DON'T SHOOT! It's all good.....let's get back to cams and carbs now.

[04'400ex'er]

Originally posted by MIKE400EX
DON'T SHOOT! It's all good.....let's get back to cams and carbs now. Thanks. And sorry for the remark. Just my way of thanking the guy for some information I asked. Hes helped me out on other threads and many other people too. I guess it was stupid to defend myself aginsed the comment from Mike400. Sorry for the remark that you all thought so funny and sorry for the "brain fart".

[onebad450r]

I just installed a TC 924 mx cam in a freinds bike. He has a slotted cam gear, so I had to degree it in.....Since I had everything there to work with I figured that I would check the specs out on the intake. I came up with .346" lift on the intake and 239 deg. of duration at .050"

His bike really rips from low to mid-range but kind of falls off in the upper rpm,s. Kinda of makes since, this is a mx cam. This cam is designed to get you out of the turns and rough stuff and up to speed quick to clear jumps or just to stay in front. This is just my 02 cents, take it for what it is.

[04'400ex'er]

Someone might have already answered this question but I would like a blatin answer if possible: What kind of HP gains will I get with just adding a cam to my steup in the signature compared to the gains I noticed when I got my full system?

[Joecool1264]

A stg 3( the old stg 2) is a mid to top end cam. You'll notice a gain, lots of top end. While your in there do a piston & really feel it rip.My 2cents.

[04'400ex'er]

Originally posted by Joecool1264
A stg 3( the old stg 2) is a mid to top end cam. You'll notice a gain, lots of top end. While your in there do a piston & really feel it rip.My 2cents. I want to do a piston but wasnt gonna mess with that till I need a ring job. when I do the cam, I will have the head off so access to the piston will be easy, correct? My motor is new and I don't want to lose any reliability that is why I wasnt gonna mess with the piston. but If it will be easy to do when I do the cam then I prob will.

[Dave400ex]

The piston won't hurt the reliability as long as you stay with a good compression, like 10.8:1.

[duke416ex]

No the head won't be off when you put the cam in, just the valve cover, but just the 4 head bolts and 4 ex. manifold bolts to take off in order to remove the head. I have a quick question, I just bought a cam that is supposed to be a white brothers, the numbers on it are 7eht, anyone know which one it is, I looked on theur website with no luck and did a search on here. Sorry for butting in on your post.

[cals400ex]

a cam will benefit you with the full HMF, even if you run the stock piston. i would probably unbolt the head and at least put in a thinner head gasket. you do not need to remove the cylinder and piston if you don't want to change the piston. it isn't that hard as long as you have a manual. i would look into a stage 1 hotcam or a stage 2 hotcam if your going to use the stock piston. a stage 3 might be a little much (although it will run fine, especially in the upper rpms).

[04'400ex'er]

If I do a cam I want to get the most radical I can get. At some time, whether when I put in the cam or later down the road, I am gonna build a 416 motor. If I do get a hot cams, It will be a stage 3. But everyone has a hotcam, I want to find a different cam possibly web cams that is hotter in the mid to top range power, and that not everyone has. I have the durations of the cams that you listed and some others, but I don't know how to read them, so tomorrow I am gonna make a trip to my mechanics shop and ask him which will make more power. If anyone has any other cam companys they know of that havent been listed that would be worth a look, please let me know.

[Rico]

HRC Cam

[04'400ex'er]

Originally posted by Rico
HRC Cam Will the HRC cam overpower the hotcam stage 3? I have herd on the 450r there are more powerful cams on the market but didnt know about the ex?

[cals400ex]

the stage 3 is "hotter" than the hrc at high rpm. web and megacycle both make more aggressive ones. i have a feeling you will need larger than a 440 to benefit from the really aggressive ones though.

[boystoys]

i didnt read all the responses... so i am not sure if this has been suggested... but i think this is the cam i am going to get...

a XR400 Cam... its "plug and play" you dont have to take parts off like the others, from what i understand... and i also understand that it is a good performer....

[04'400ex'er]

Originally posted by cals400ex
the stage 3 is "hotter" than the hrc at high rpm. web and megacycle both make more aggressive ones. i have a feeling you will need larger than a 440 to benefit from the really aggressive ones though. If web and megacycle make hotter cams than the stage 3, then that is what I am looking for. When you say you think I will need a bore larger than a 440, do you mean I would be better off with a milder cam such as the stage 3 on a 416, are you basically saying that the hotter cams will perform worse than the stage 3 for example on a 416, but will perform better on lets say a 465? Is the 479 grind web cam the hottest web makes for the 400? If not, which is?

[4everhonda]

You should go with a web cam if your wanting all out balls to the walls power, the 55-911 is badass but you will need this - Special profile designed for racing engines. Must be used with racing springs / shortened guides, high compression piston and exhaust system. Compression release removed. Hardwelded rockers highly recommended! (get the rocker arms they are worth the money) go to http://www.webcamshafts.com/ to check them out. Best investment to be made over all will prob cost around 500 just for cam springs and rockers :(

[Rico]

Originally posted by cals400ex
the stage 3 is "hotter" than the hrc at high rpm. web and megacycle both make more aggressive ones. i have a feeling you will need larger than a 440 to benefit from the really aggressive ones though.

Cal your forgetting the HRC is a honda cam and the other is a hot "blowup" cam.....:devil:

the HRC is a good all around cam from top to bottom, not just for bottom or just top end.

THis stage 3 cam is new to me, what's up with it Cal???? Cost the same as the others??

[UglyMotha™]

Originally posted by Rico
Cal your forgetting the HRC is a honda cam and the other is a hot "blowup" cam.....:devil:

the HRC is a good all around cam from top to bottom, not just for bottom or just top end.

THis stage 3 cam is new to me, what's up with it Cal???? Cost the same as the others??



The stage 2 has been bumped to the stage 3 and hotcams is making a new cam which will be inbetween the two and calling it the stage 2

[04'400ex'er]

I think I am going to go with the hotcam stage 3, just because I dont want to mess with the hardened rockers. My mechanic reccomended kibblewhite valve springs too. would I benifet from different valves, such as oversized valves. would It be worth porting If I am going to keep the stock piston, and only change the cam? Anything else I should do such as a 3 angle valve job? different seats? what else should I do for reliability and/or power along with this cam?

[wilkin250r]

Anybody ever degree the XR400 cam and get basic specs on it? I'd like to see how it compares to some of the other cams.

[MIKE400EX]

Here ya go Wilkin!

Lift Duration@.050"Lift
Intake Exhaust Intake Exhaust
stock 400EX cam .316 .302 234 238
XR400 .326 .321 240 244
HRC .350 .339 254 256
GT Thunder .350 .345 256 256
WB Track .350 .345 256 256
WEB 450/451 .350 .345 256 256
WEB 479 .378 .378 250 250
WB All Around .345 .335 240 248
HOT/stg1 .354 .354 244 244
HOT/stg3 .346 .346 254 254

[cals400ex]

yes rico, hotcam is making a new stage 2 cam and what they previously called the stage 2 is now called the stage 3. i realize that is a honda cam. however, for the price i just don't think i would get it. i have a feeling my TC cam is pretty similar to the HRC. it feels as if this TC has a bit less duration than the stage 3 hotcam. i prefer the higher duration so it runs to a higher rpm. yes, i can easily run past the stock rev limit when drag racing with this TC cam but it doesn't go quite as high as the stage 3 did. yeah the hotcams are known to blow up but their new ones seem to be built pretty strong. i know i had one of the old stage 2 hotcams and the flange was pretty big. later i guess they changed to a flange that was smaller, like what would come on other cams i see for the 400ex.

[wilkin250r]

Thanks, Mike!

Wow, the HRC cam looks pretty good, it has slightly more lift and duration than the hotcams stage 3. I wonder what the lobe centers are, if they have equivalent overlap.

I didn't realize the XR400 cam was so bad, it's barely better than stock. Even the WB All Around cam has more lift and duration.

Anybody ever look into the WebCam 463/9i ? Huge lift, huge duration. That's going to be really high RPM, that's gotta be like a drag racing cam. That thing would give you a 2-stroke powerband. :blah:

[cals400ex]

that hrc is a bit more aggressive than i was remembering. i heard laz say that the stage 3 is better if you like to always be at the rev limiter and the hrc is more "all around" and will provide nice gains everywhere.

[cals400ex]

Originally posted by wilkin250r
Thanks, Mike!

Wow, the HRC cam looks pretty good, it has slightly more lift and duration than the hotcams stage 3. I wonder what the lobe centers are, if they have equivalent overlap.

I didn't realize the XR400 cam was so bad, it's barely better than stock. Even the WB All Around cam has more lift and duration.

Anybody ever look into the WebCam 463/9i ? Huge lift, huge duration. That's going to be really high RPM, that's gotta be like a drag racing cam. That thing would give you a 2-stroke powerband. :blah:


i would love to try that web cam just for the heck of it. this megacycle cam is pretty aggressive too:

mega X6 .402 .385 270 262 @.040

[wilkin250r]

Originally posted by cals400ex
i would love to try that web cam just for the heck of it. this megacycle cam is pretty aggressive too:

mega X6 .402 .385 270 262 @.040

.402 lift is huge! That's almost 0.1 over stock, I'd be worried about piston/valve clearance.

Please tell me the duration is a typo. Who the #*$& measures the duration at 0.040? Are they trying to hype up their numbers and hope we won't notice?

[04'400ex'er]

Anybody have any reccomendations on anything to do to the head while i have it off such as a 3 angle valve job or oversized valves. Any other HP boosters to help compliment the cam.

[MIKE400EX]

.040" (roughly converted from 1mm) is a benchmark reference that is commonly used in cam specs outside of the US market.

[Dave400ex]

04'400ex'er having a good port/polish and valve job when it's off would be good to have done, if you plan on doing some more motor later, such as a carb...

Cal, which TC cam do you have? I have the TC XC cam and it makes some crazy power down low, just wondering what you thought of yours...

[cals400ex]

i run the TC 924 (MX) cam. it seems to run really well at mid rpms. high rpm's (around stock rev limiter and higher) it starts to fall on its face. it is a little noisier than the stage 3 hotcam that i used to run. however, that hotcam was no louder than stock. it is nothing near as loud as a stage 1 hotcam though. i would get the cam again if your looking for killer midrange power. i would just like a better drag racing cam (which actually this one isn't too bad for that, but i am sure there are betters)


how exactly do you convert the .040 to .050" when comparing cams. megacycle does measure them with .040" and i am not sure what the difference is. if i keep my 400ex i think i am going to try a better cam for drag racing but i have no idea which one.

[wilkin250r]

Originally posted by cals400ex
how exactly do you convert the .040 to .050" when comparing cams. megacycle does measure them with .040" and i am not sure what the difference is. if i keep my 400ex i think i am going to try a better cam for drag racing but i have no idea which one.

The question is; when does the valve open, and when does it close? Well, the problem is the definition of "open". Although the valve is technically open at 0.003 inch (about the thickness of a piece of paper), you're certainly not really getting any useful amount of airflow through such a small opening, so is it actually "open"? However, at 0.050" (a little less than 1/16 of an inch), you actually start to get real airflow. The same is true for closing. For this reason, cam designers have chosen .050 as "open" in order to allow useful comparison between specs.

Your valves don't open instantly, they lift open. Obviously, your valves will be open at .040" before they will be open at .050", and obviously close later. This means you have longer duration at .040" as opposed to .050" For example, if you define 270 degrees @.040", it might only be 260 degrees @.050".

Lift is good. Generally speaking, more lift equals more horsepower. However, too much lift can cause problems with the valves and springs, which is why many cams require stiffer valvesprings, and some of them even require shorter valve guides. Also, the difference between .345 and .350 really isn't going to make much difference at all. You'll notice a difference of 10 degrees duration, but you won't really notice a difference of .010 of lift.

Duration is a compromise. 240 @ .050 duration means the valves are "open" (0.050 lift or more) for 240 degrees of rotation. Longer duration means less bottom end, and more top end. Under 240 duratation is probably a "torque" camshaft, anything over 260 is going to be a hi-rev camshaft.

There is another aspect called "overlap" which is also important. It gives the total rotation that both intake and exhaust valves are open. More overlap means a high-rev, peaky powerband. I would need to know the lobe centers to calculate overlap.

Cals, if you're looking for a drag-racing camshaft, you probably want maximum everything. Maximum lift, and maximum duration for hi-rev power. The only issue you need to be careful about is make sure that your engine is capable of the higher revs that the camshaft needs. I don't know if the mega X6 or the WebCam 463/9i would go well with a big-bore stroker motor. The loss if upper RPM power due to the heavier piston and longer stroke may not go together well with a camshaft that has poor low rpm performance.

[wilkin250r]

If this thread is destined for the FAQ section, let me know. I'd like to go back and delete some of the useless posts.

[cals400ex]

that helps out a lot. i have never really researched all of that out but it all makes sense, after you explained it. where does lobe separation angle come into the picture?



yes, i was going to build a stroker but i have been told not too for drag racing. i realize that web or megacycle x6 may be too potent for my 426 motor. i am just not sure if something like the stage 3 would be best or if my motor would benefit from something a little more aggressive.

[wilkin250r]

Originally posted by cals400ex
that helps out a lot. i have never really researched all of that out but it all makes sense, after you explained it. where does lobe separation angle come into the picture?



yes, i was going to build a stroker but i have been told not too for drag racing. i realize that web or megacycle x6 may be too potent for my 426 motor. i am just not sure if something like the stage 3 would be best or if my motor would benefit from something a little more aggressive.

Why would the web or X6 be too potent for a 426? I would think that either would be good for drag racing, even for a 426. I don't think you would run into problems with high revs until you got beyond 440cc. However, I would suggest you take the advice of a professional engine builder over my advice.

Ordinarily, you would think the intake valves open right after the piston reaches the top of the stroke, and then close right when the piston reaches the bottom of the stroke, right? No way. That works up to about 2000rpm, then things get more complicated, and more interesting.

Earlier I spoke about overlap, when both intake and exhaust valves are open. This can help build lots of power, but only in the upper RPM range, and it makes for terrible low RPM performance. So either the lobe centers, or lobe separation angle, would be used to calculate the overlap. The closer the lobe centers (or smaller lobe separation angle), obviously more overlap.

In general, like duration, overlap is a compromise. More overlap will make more upper RPM power, and less low RPM power. Drag racing cams are designed for high RPM, and will have more overlap. Duration and overlap generally go hand-in-hand. More often than not, camshafts with longer duration will also have more overlap, and thus built for high RPM power, but sacrifice low-end torque and performance.

[cals400ex]

that helps too. thanks

i am not sure why i think the megacycle x6 and the aggressive web might be too much for my bike. it is only 11:1 compression. i don't know. if i keep the bike i might just buy one and find out.

[wilkin250r]

Lower compression is actually a little bit better for high revs. Really high compression engines don't like to rev really high. I'm not exactly sure of the physics behind it, I'm trying to find that out right not. However, I don't think you really get into a problem until you have a REALLY high compression, like more than 13:1, and you're trying to run really high RPM, like better than 9000.

[MIKE400EX]

Wilkin,
I believe that compression theory is true for 2 stroke gas engines not 4 stroke.

[wilkin250r]

Is that just because 2-stroke engines rev higher, and thus more susceptible to the problem? Would it be related to the heavier rotating mass of the 4-stroke engines?

Because compression is universal on both two-strokes and four, I would imagine any issues related to compression would also be universal.

I really need to know the physics behind it before I can accept such generalizations.

[cals400ex]

i will leave that job up to you two. :D



well, i guess it wouldn't have an effect on me anyways because my compression isn't that high in the first place.