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Senior Member
Matt, The 479 is the WEB cam! (TYPO) The Megacycle cam with 254 deg.@ .040" is more like 250 @ .050" (also guessing) Must be too early yet in CA!
Ever notice that the WB all-around is just about a copy of the XR cam, and the GTT-WEB 450/451-WB Track are also very close to the HRC cam? Maybe Honda does know what runs best all along - or there are some cam grinders that don't want to put much effort into R&D of new grinds!
Last edited by MIKE400EX; 03-22-2002 at 11:15 AM.
Mods: Big Gun FS w/MM quiet core, no lid , K&N, FCR41, 11.3:1 440 and Web 479 cam, porting, no choke. Works TRS fronts & Ultracross rear shock, a few other goodies
450R,250EX, Blaster, Banshee
politically incorect..!
Good thread..!
I was just going to slap my piston in and call it good enough.. but now...
Leo
You know the world is going crazy when France is accusing the US of arrogance, and Germany doesn't want to go to war.
Senior Member
Leo, You still haven`t put your Piston and Cam in?
Make sure this goes in the FAQ Forum.
Thanks for the Support: Maier, Moto-Xperts, Rekluse, Teixeira Tech, Fox Racing Shox, BK Performance, DWT, Rath Racing, Quadtech, Streamline Brakes, Precision Racing Products, PowerMadd, Spider Grips, ASV Inventions, IMS Products, CV4, UNI.
Larger Member
Even with the specs we have, the ramp angles can really affect the powerband.
If I were designing a cam from scratch for this motor, I'd certainly pay attention to what Honda offered. Actually I'd make roller rockers with far more radical ramp angles.
My friend called Web today, the 479 is only a week out now. They said that the decompression mechanisim comes off, and you need to press the sprocket's flange off too. They only deal with the bare cam.
Why can't the decompression release be used? Same basic cam, I'm wondering if Honda's patent has anything to do with it...
The pressing on and off of the flange concerns me. Is it on there in such a fashion that it can't be pressed on at the wrong spot? Getting it pressed on and then finding out that it's off by a few degrees would really suck.
Senior Member
The flange only goes on one way, it's got the "big tooth" syndrome. Make sure that the flange is seated against the shoulder on the cam completely before you put it back in. Otherwise the sprocket will run out (wobble) as it spins. BTW, the flange on my GTT was not seated properly.
I've also wondered why the decompression devices always get removed. I could see the removal if the cam gave a very lopey or rough idle, but I'd think a mild one would be OK?
Since we keep visiting the hardened rocker subject I'll share some findings based upon similar OEM auto design.
Use hard welded rockers if any of the following apply: 1. the cam is hard welded. 2. ramp angle (valve opening rate) is increased 3. higher RPM is expected (modified rev box) 4. running at sustained high rpm 5. higher pressure valve springs are used 6. the motor runs much hotter than stock 7. you run (the motor) on alcohol 8. you don't like to change your oil 9. the rockers are already worn out.
Shouldn't have to hard face them if none of the above and: 1. the cam is not hard faced or is of similar material and hardness as stock 2. stock springs are used 3. you've got a rollerized set-up. I'm sure I missed a few things but it's a start!
Mods: Big Gun FS w/MM quiet core, no lid , K&N, FCR41, 11.3:1 440 and Web 479 cam, porting, no choke. Works TRS fronts & Ultracross rear shock, a few other goodies
450R,250EX, Blaster, Banshee
Always wear your helmet!
Matt, the flange is splined & got one wide one so it can't be oriented incorrectly...
I'd also be interested to hear why the decompressor can't be used.
Always wear your helmet!
Looks like you beat me to it Mike.
Here's a question on the hardweld rocker topic...
If you get your rockers hardwelded unnecessarily - and the cam is not, does the cam then become the wear item?
Registered User
matt, in some of the xr fourms i have read about the auto decompressor. the xr owners remove the auto decompessor from the cam for easy starting of there bikes ( xr400, 600, 650 ). they claim that by removing the decompressor it reduces valve train noise and some claim that the bike revs quicker. the main deal with removing the auto decompressor and not using it is there are two oil holes in the cam that oil the decompressor. the oil holes have to be welded up or there will be a loss of oil pressure to the other oil holes in the cam lobes. i would ask Web if they weld up the oil holes. i do not think Web or the other cam grinders weld the oil holes up. i am not sure but could this be the reason for hard weld rockers?
yes the flange is made so it can't be pressed on wrong.
also if the auto decompressor fails there are small rollers and springs in the one way clutch that would do some damage to the motor.
2000 400ex with a mikuni tm38 carb, tc racing pipe, rebuilding motor
Senior Member
Sorry, not trying to take any thunder away!
Yes, the cam would certainly become the "wear item".
I don't think it would matter much as long as the oil is kept clean. The hard chrome plating on the stock rockers is almost as hard as the welded type hard facing. It's just not very thick and once worn through (which could happen during break in - especially w/used rockers) the soft base will quickly gall and/or wear.
Mods: Big Gun FS w/MM quiet core, no lid , K&N, FCR41, 11.3:1 440 and Web 479 cam, porting, no choke. Works TRS fronts & Ultracross rear shock, a few other goodies
450R,250EX, Blaster, Banshee
Senior Member
So if I got a TC XC Cam that is a Drop-In that does not need Hardface Rockers, but I Hardfaced the Rockers anyways, the Cam would be the Wear Item?
Thanks for the Support: Maier, Moto-Xperts, Rekluse, Teixeira Tech, Fox Racing Shox, BK Performance, DWT, Rath Racing, Quadtech, Streamline Brakes, Precision Racing Products, PowerMadd, Spider Grips, ASV Inventions, IMS Products, CV4, UNI.
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