How does this build sound?

[MtnEX]

XC/Trail engine

'05+ reverse bottom end

440 bolt-on kit... 89mm & cylinder

Gaskets done per Micky Dunlap article

Pump gas compression

HD head studs & timing chain

Stage 1 Hotcam

Possibly a Sparks Key or XR 250 CDI.

My current head (redone)


Not sure what to do with the head...

[jasonwayne222]

if ur goin 440 do it right, get the kibble white valves and do a stage 3 cam, and a 450r carb. definitely a port and polish

[jasonwayne222]

oh and sparks keys are not recommended for higher compression engines, or an engine with a lot of mods like urs, they build up a lot of heat and will cause detonation with all the mods, their mostly for a stock comp. engine, with small mods

[paganmac_10]

I would say, go with the stage 2 cam, stage one is just a lil to mild for a 440, bigger carb, and either a fan on the oil cooler, a second oil cooler, and maybe another bigger oil tank, gotta keep that 440 cool......

[odog]

Originally posted by jasonwayne222
if ur goin 440 do it right, get the kibble white valves and do a stage 3 cam, and a 450r carb. definitely a port and polish x2 and since your following mickey dunlap on the gasket article go ahead and order the secondary oil cooler from him also.

[MtnEX]

Well, I had in mind to use a radiator sized oil cooler.

How's that sound?

I thought it would look cool and keep the oil cool.



As for the cam... I thought stage 1 would be the way to go for an XC/Woods/Mtns/Trails engine???

If I do anything with this bike, I don't want to loose anything the 400EX already has... like good low end...


Maybe I have the wrong idea on the cams though?

I was thinking in terms of low/mid/top "end".

[TRXRacer1]

Stg 1 is not pointless with a 440 but a 440 is pointless with a stg 1. Don't even bother with a 440 if you're not going to let it breathe.

If you want pump gas compression then forget the Mickey gasket install, it's counter productive to your goal.

The sparks key is HIGHLY counter productive to your pump gas goal! Run from this idea.

The head does NOT automatically need kibblewhite valves! The OEM valves are quality and only if they are out of spec should you consider an aftermarket replacement. Any other way of thinking is not thinking and just a waste of money. Just replace what needs replacing and swap out the valve seals while in there.

Forget the 05 bottom end because it this point you're throwing way too much money at a 400ex. Between this and a serious build you could buy another quad and probably a model that will beat what you just built.

[jasonwayne222]

kibblewhite +1mm valves are worth it, wasnt talkin about stock size valves made by kibblewhite, and trx1 u arent smarter than everybody and u always talk like u are so pull the stick outa ur *** when u reply cause every post i read from u ur being a dickhead to everybody

[jasonwayne222]

and u talk about its pointless if u dont let it breath but say bigger valves are pointless?? u are being counter productive in ur statements buddy

[katch26]

EDITED - thanks

As far as cams with a big bore youd def want to go bigger than stg 1 because the big bore will have additional torque from just a larger displacement to "make up" any low end lost by going to a larger cam.

[Miami_Vice454]

would putting a bigger cam help his goal of pump gas, i know it reduces overall compression because the air has more time to escape but does that count for the gas too? i definately do know however that if you are doing the 440, go with stage 2 becasue that 440 will have tons of bottom end anyway.

[katch26]

ultimately cams and cam events overlap etc will have an effect on running compression (dynamic) but how much is the question? I guess its possible but youd have to sit down and do a lot of actual measuring and calculating.

[riotact]

What parts did you get to get reverse in your 2000? Is it just the case,tranny,and cable or do you need other things.I'd really like to get reverse in my 01 without having to swap the whole bottom end out.

[slightlybent47]

[QUOTE]Originally posted by MtnEX
[b]XC/Trail engine

'05+ reverse bottom end

440 bolt-on kit... 89mm & cylinder

Gaskets done per Micky Dunlap article

Pump gas compression

HD head studs & timing chain

Stage 1 Hotcam

Possibly a Sparks Key or XR 250 CDI.

My current head (redone)



I see you have been on this site for some time and I'm sure you know that all the info you get here is not good advice. Some is and some is not.

I'm no expert but I do have a lot of seat time.

Here is my 2 cents

If I was going to do woods ridding or racing, I would look at what is most important. That is ratability and control. The ex as a stock machine is a great woods bike as it is.
The main thing about motor mods is the more power you have the less control you are going to have in tight woods ridding. Yes it will haul *** on long strait away but how many strait away are there in the woods, not many.

First thing get as much ridding gear as you can so your safe if you crash.
Then work on the suspension, if you have all that done then work on the motor. The ex has more motor then it has suspension so do that first.

On the motor stay with the stock bore or if you feel you need a bit more then no more then a 416. Then the compression, it is 10:1 stock so with 11:1 you can still run pump gas. So I'd keep it low. The head on the ex is where most of the performance is, they are so detuned for durability that is where most of your hp is.

Do a recreational P&P so it can breathe a little bit but not so much you start to lose durability. With a rec P&P and a 416 you don’t need the HP valves and you won’t have any problems with the head gaskets. A slip on pipe would help and Bump the jet up a little to make up for the mods.

With woods ridding having to much power will only make it hard to control on slow tight trails. Then when you do hit a long strait away and your in front you can hold off your apponet by blocking.
There is most likely not much room for someone to make a pass anyway.
If you do too much to the motor you may run into some over heating problems when the trails get tight and slow and you throw in the mud and dirt that gets caked on that will cause you to over heat. The ex is air cooled so too many mods will most likely hurt you then help you.

It's fun to have a real fast 400 but in the woods I would rather be on a stock 400 than my built 400.

But thats just me, what ever you do I hope it is what you want and workes for you.
Safety gear first, suspension next then light motor mods.

[TRXRacer1]

Originally posted by katch26
ultimately cams and cam events overlap etc will have an effect on running compression (dynamic) but how much is the question? I guess its possible but youd have to sit down and do a lot of actual measuring and calculating. You're exactly right katch26, dynamic will be effected. The difference between a stg 1 and stg 2 cam is about .2 and stg 1 to stg 3 is about .5 on CR.

Jason, your new idea of +1 valves is still a bad idea on a build like this. It's a bad idea on most builds. You keep giving out bad advice and I'll keep the stick in my *** and continue to reveal internet nonsense.

[MtnEX]

Originally posted by riotact
What parts did you get to get reverse in your 2000? Is it just the case,tranny,and cable or do you need other things.I'd really like to get reverse in my 01 without having to swap the whole bottom end out.

ME?

I was talking about a reverse bottom end.

But I do plan to investigate and see what all the differences are.

[Miami_Vice454]

You're exactly right katch26, dynamic will be effected. The difference between a stg 1 and stg 2 cam is about .2 and stg 1 to stg 3 is about .5 on CR.

Thanks trxracer1. And do you know what the difference is from stock to stage 1?

[jasonwayne222]

i originally suggested doin a 440 build right, if ur gonna spend the money for 440 kit u might as well go all the way with the biggest cam, valves, and do the highest comp. piston u can get to compensate for the loss in dynamic compression and run c12 to give a little more pep and keep it cool,carb, p&p, etc. if he would do these things with possibly even a stroker crank then no the bigger valves wouldnt be a waste, if he wants to keep it a bit more mild then ya i wouldnt do the bigger valves or the 440 for that matter, he might as well do a 416 with the mods that he wants to do, at least that way hell still have one more bore left, if he goes 440 then when it gets out limits even tho it should be a good while, then hell have to resleeve it. oh and ur still a dick. i just really cantstand trx1, ur a doosh

[riotact]

Originally posted by MtnEX
ME?

I was talking about a reverse bottom end.

But I do plan to investigate and see what all the differences are.

Yep. I had an idea awhile ago of getting 05+ case and tranny and use all of my 01 parts in it.It would cost about $150 instead of 5 to 6 hundred for a bottom end.The best way to compare them would probly be to have a 99-04 and an 05+ manual but for now I only have the 99-04.Just a thought but if it would work it would be a great upgrade for us older ex riders.

[TRXRacer1]

Originally posted by Miami_Vice454
Thanks trxracer1. And do you know what the difference is from stock to stage 1? They are very close mainly due to the similar duration.

[Miami_Vice454]

and ur still a dick. i just really cantstand trx1, ur a doosh

wow harsh words, yea he is am little sarcastic (in your words, a dick) but he does have good info.

[TRXRacer1]

Originally posted by Miami_Vice454
wow harsh words, yea he is am little sarcastic (in your words, a dick) but he does have good info. Thanks Miami. No worries though, I kind of feel sorry for the dude. He needs some tougher skin or something. No need getting emotional over some words on the internet. There's simply more important things in life, like learning how to spell douche. Insults are far better when they're spelled correctly.

[katch26]

Originally posted by TRXRacer1
Thanks Miami. No worries though, I kind of feel sorry for the dude. He needs some tougher skin or something. No need getting emotional over some words on the internet. There's simply more important things in life, like learning how to spell douche. Insults are far better when they're spelled correctly.

win

[Miami_Vice454]

nice, i rofled katch26. that was epic

[jasonwayne222]

ha ha i love gettin a rise outa people on the internet, dont know u nor will i ever see u so i really dont care.

[MtnEX]

I want to "note" that I already have a 450R.

So I didn't start this train of thought like many 400EX owners do.

I don't want to try to build a race quad or try to get this thing as close to a 450 as possible.

My goal was only to give it a good bit more snap and quickness from corner to corner, without loosing any of the good stall resistant qualities of the stock EX.

In other words, a 400EX that can be a faster trail bike.

Does this change your suggestions? Or do they stand?

[MtnEX]

Originally posted by riotact
Yep. I had an idea awhile ago of getting 05+ case and tranny and use all of my 01 parts in it.It would cost about $150 instead of 5 to 6 hundred for a bottom end.The best way to compare them would probly be to have a 99-04 and an 05+ manual but for now I only have the 99-04.Just a thought but if it would work it would be a great upgrade for us older ex riders.

Well, it looks like most of it is different.
Different cases, different gears, etc...

Doesn't look possible on my end to use anything much from our bottom.

The crankshaft stuff from ours "might" work in the new bottom.
Dunno, not sure if the "teeth" are the same.



Anyways, and maybe someone mentioned it...

We are probably better off to sell and move to an '05+ machine."
I may do that... unsure...