best kit

[EricB]

for the riding that i do i would want more low end and more mid power. i have read that the 406 and the 416 would be the best. i would for sure pair it with a cam and exhaust at very least, oh and a k&n for sure, probably this week. i'd like to go with a new carb and a valve job, head ported and polished, oversized valves and titanium valve springs..but well that all costs a lot of cash.

i want to keep the gearing the same, the gearing seems fine, i would rather tune the engine and not have to give up any top end.

anyhow any input is welcome, as usual, please let me know from your PERSONAL EXPERINCE, not what you have read.

[Tommy 17]

all the motor mods u see in my signature cost right around 900$ that is also including new rockers and springs... also with all the mods u won't want ur stock gearin anymore... it revs way to fast... get a 16t front or go down 1 in the rear...

[ChadEXer]

I disagree with 400ex21. you will want to keep the stock gearing! you said you like the stock gearing and i like the stock gearing also, when I had my 416 kit in(JE10.8:1 piston and XR cam) i put a 16t front sprocket on and I didnt like it. keep the stocker,,the only thing you should consider is if you drag race, then you might want to drop to a 14t in the front!!
Unlesss you got the cash and want to spend it I dont think you should harden the rockers or get bigger valves or anything. i had the complete 416 with ported\polished head and all done for about $600 with everything and I was beating all the 440's I raced at the drags!! it was fun beating some Craptors too!!! i think you should just get a piston, cam, and have port work done,,,you will be happy!! Except dont get the XR cam, it was a nice drop in cam and gave nice gains,, but i always wished i would have put a little more aggressive cam in!!! If I was you I would get a 11:1 JE piston and a TC cam!!! Go ahead and get the 416 piston, im sure the 406 adds nice gains but for just about the same price you prolly will wish you would have gone ahead and done the 416!! Good luck!!!
Chad

[EricB]

thanks chad i like hearing things from people who have done it. hmm about the 11:1 i think i'd stick to a little lower compresion just so i can run pump gas with out any worrys at all. a port and polish job is on the plan for sure, and when i do get a new cam it will be an agresive one. i don't see the point in using a "drop in" cam, why go through the trouble for a near stock cam. but i think the 416 kit is where its at, so long as you do other things along with it.

[Scott]

If you want the cam to last, you should hard face the rockers. Or else be ready to tear it down again in a couple months. The stock rockers are fine with the stock cam, but if you "go more aggressive" with the cam, the larger lobes (more lift) and the steeper lobe ramp will eat the stock rockers in no time.

But it's your money and your quad.

Good luck!

[ChadEXer]

There are a lot of people who agree with what Scott says but when i talked to the engine builders, most of them dont think the rockers need hardened even with an aggressive cam! There are plenty of cams that are much more aggressive than the stock cam yet dont need hardened rockers! The TC MX or XC cams for example!! Mickey at FST runs the stock rockers on Chad Duvalls 500EX with an aggressive cam and he hasnt had any problems!!!
As far as the piston, you should probably just get the 10.8:1 piston that way you can run regular pump gas with no problem,,,thats why I put the 10.8:1 piston in mine but when i would just barely get beat i would think, If i would have went to the 11:1 and ran race I might have beat him,,,If I done the 416 over thats what i would do, but a lot of people dont like running race gas,,its expensive and can be hard to find!!!

[Scott]

As far as the rockers go, I'm just telling you what I'm seen with cams in 300ex's and 400ex's. As for Duvall's FST EX, do you honestly believe that his engine is not torn down and checked out on a regular basis?

[EricB]

I meen i won't be doing this for quite a while for a reason, i'm going to be doing everything that i need to do. i'm a firm beliver in if your going to do it, do it right. if you can't afford to do something, like get the rockers hardend then don't bother tell you can afford it all. admitdily my engine won't be torn down very often, so if there are things i can do to improve the longevity of my ride i will. but like i said most this wont happen for a while. only thing i'm going to do now is new exhaust K&N filter and fab up some air scoops. and when you say harden the rockers..i get a little confused, what exactly is the process, just tempering the steel? they can't be welded in one place right? i thought that this engine used pushrods for the vavles?

[Scott]

No pushrods. The rockers ride on the cam and operate the valves.

Hardfacing the rockers is having the "face" (the part that rides on the cam shaft) of the rocker hardened so it's not worn away as easily by the friction and pressure of riding on the cam lobes.

[Tommy 17]

chad when i ride my 406 with the 15t and 20 rears i can't stand it i am constantly shifting and it revs way to fast... mayb its only bc i am 130lbs... id unno but when i put my 16t and 20s on i love it... the 16t with 18s is perfect for a race track for me...

scott i have a tc mx grind cam and new stock rockers and its been about 5 months of hard riding on it with no wear at all...

[EricB]

ok i thought i heard someone say something about pushrods. but yeah..that would be pretty hard to do on a single cylinder engine. typicly aren't the pushrod style valve setups used in V engines? ok now i know what your talking about when you hardface em. lets just say i'm learning alot about engines and things, i used to know almost nothing but i've been doing a lot of question asking and reading quite a bit. i could tell you how to do a lot of things, but i probably couldn't do it my self hehe. oh well learning is 1/2 the fun, right? =P

Edit: er, and with the pushrods you wouldn't be able to have a OHC right?

[Scott]

Pushrods would be used in a V-engine that has a single camshaft. Anything with an overhead cam doesn't use pushrods. If you looked at a 91 Vette ZR-1 engine, it's a 350 CI engine, but it's an overhead cam setup. Actually, it's a DOHC, 32 valve setup. Pushrods just fillin the distance between the rockers and the valves.

[ChadEXer]

Originally posted by 400ex21
chad when i ride my 406 with the 15t and 20 rears i can't stand it i am constantly shifting and it revs way to fast... mayb its only bc i am 130lbs... id unno but when i put my 16t and 20s on i love it... the 16t with 18s is perfect for a race track for me...

scott i have a tc mx grind cam and new stock rockers and its been about 5 months of hard riding on it with no wear at all...
16t with 18's might be OK but its too high for 20's i think!! I just like the stock gearing the best. Its not too high and not too low,,Honda did good with the gearing on the 400's!! Even with the 505 kit Im gonna keep the stock gearing,,,unless I dont like it but im pretty sure I will!!
TC told me the same thing that Mickey at FST said, the stock rockers are plenty hard enough and they dont have any problems with them in their motors!!!