What make a 416ex, 426ex and 440ex

[grillo2k5]

I have a 05 400ex with Full exhaust, filter and some other goodies but I want to give it some more power and would like to know what exactly make the 400ex a 416 426 etc. and do they have the same reliability and how much hp and tq does it add (roughly) compared to each other

[2004exrider]

Stock bore is 85mm.
416- 87mm, a lot of people like to put in a 416 because it is a reliable piston and still powerful. If well built (cam, good exhaust, port and polish, etc) can hang with a 440. The 416 in the dyno section is pushing around 34Hp i think.

426- 88mm, last bore you can go on the stock sleeve but its better to get a different sleeve because you may have heat issues. Power is gonna be close to the 440.

440- 89mm, You have to buy a bigger sleeve, heavy duty headstuds, aftermarket clutch is reccomended, stronger connecting rod, and preferably a good synthetic oil to make it as "reliable" as you can. They dont rev as fast as fast as the other bores but they have a lot more torque. A good 440 will push 40hp or a little more if built right.

To get the full potential out of these engines its best not to skimp out anywhere. A good full exhaust, K&N/Uni filter, proper cam, etc. The engine can only be as reliable as the person who built it.

Jimmy

[Unverfehrt400ex]

Very well said.

[underpowered]

Originally posted by 2004exrider
Stock bore is 85mm.
416- 87mm, a lot of people like to put in a 416 because it is a reliable piston and still powerful. If well built (cam, good exhaust, port and polish, etc) can hang with a 440. The 416 in the dyno section is pushing around 34Hp i think.

426- 88mm, last bore you can go on the stock sleeve but its better to get a different sleeve because you may have heat issues. Power is gonna be close to the 440.

440- 89mm, You have to buy a bigger sleeve, heavy duty headstuds, aftermarket clutch is reccomended, stronger connecting rod, and preferably a good synthetic oil to make it as "reliable" as you can. They dont rev as fast as fast as the other bores but they have a lot more torque. A good 440 will push 40hp or a little more if built right.

To get the full potential out of these engines its best not to skimp out anywhere. A good full exhaust, K&N/Uni filter, proper cam, etc. The engine can only be as reliable as the person who built it.

Jimmy

very nice.

the 416 is great for trails and play riding. more umph to do what needs to be done adn still stay reliable.

the 440 has gobs of low end and will still run of top. can be reliable if built correctly and maintained.

the 426 is kind of the best of both worlds. Revs quick and seems to be very reliable. but has lots more low end than stock. more power than a 416 but revs faster than a 440.

IMHO, if i had a stock bike to start with, i would doa 416, than you can always go up the a 426 later on the stock sleeve. then you can either go back down or install a larger sleeve and start going up.

[400exMO]

On those bores to optomize reliabilty what else should you do besides exhaust, intake, port polish, etc. Should you get new valves, or new gaskets. I'm planning on doing 416 sometime and would like it to be more reliable than the stocker. So what all should be done?

[440 00]

this was somehelpful information for me because i bought a used bike with a 440 and did not know what gasket kit to buy

what kind of synthetic oil should i buy for my 440

[2004exrider]

Originally posted by 400exMO
On those bores to optomize reliabilty what else should you do besides exhaust, intake, port polish, etc. Should you get new valves, or new gaskets. I'm planning on doing 416 sometime and would like it to be more reliable than the stocker. So what all should be done?

416 is already a reliable bore. Just make sure to keep up on maintenace. Change oil regularly, clean air filter, JETTED PROPERLY, and that the valves are adjusted. I'd also go with a 11:1 compression ratio so you can still run on 93 octane.

Jimmy

[2004exrider]

Originally posted by 440 00
this was somehelpful information for me because i bought a used bike with a 440 and did not know what gasket kit to buy

what kind of synthetic oil should i buy for my 440

Not sure of the best brand but find one that is "wet clutch safe". Im using a synthetic/petrolium blend right now, i think its called Golden Spectro.

Jimmy

[rippin2]

tmm 416ex...in my opinion best bore for the 400ex(416) that is..i dont really knw about 426 or 440s

[grillo2k5]

Thanks for the great info now what are the recommended parts for the 416 and 426 and how hard is it to install it or how much would the installation cost and the highest pumps gas here is 91 octane would that work for the 426

one other thing so for the 426 I basically "just" replace the piston right

[2004exrider]

If it was me...
416- Stage 1 cam, thinner head gasket (xr400 or cometic), port and polish, Wiseco or JE 11:1 piston so you can still run on pump gas, Full exhaust or slip on, different air filter.

426- Same as above but a stage 2 cam and a full exhaust. For added reliability id get a stronger connecting rod, aftermarket clutch, cam chain, bigger head studs, and a thicker sleeve to replace the stocker.

Jimmy

[GPracer2500]

For whatever it's worth, I'll add this detail: Although we commonly refer to these piston kits as 416, 426, and 440 and think of that as the actual displacement, only the 426 designation is technically correct.

When the volumes are calculated out, the choices are technically:

397cc stock, 85mm piston x 70mm stroke
406cc 1mm over
415cc 2mm over
426cc 3mm over
435cc 4mm over

The 435 vs. 440 thing has always kinda bugged me--seems like false advertising or something...:huh

JE now offers a NEW 89.5mm piston which is a true 440cc. They also have a new 88.5 piston which would be 430cc. Unlike Wiseco (who I blame for the 416 and 440 misnomers--why'd ya' do that Wiseco??), JE lists the correct displacement numbers.

Occasionally, I'll see someone actually refer to a 415 or 435 but mostly people just use the designation 416 and 440.

[2004exrider]

How are you coming up with 415?
If you take .7854 x 87mm x 87mm x 70mm = 416128.482. Then take that answer and divide it by 1,000 and you get 416.128482 aka 416cc. Just curious.

Jimmy

[GPracer2500]

Originally posted by 2004exrider
How are you coming up with 415?
If you take .7854 x 87mm x 87mm x 70mm = 416128.482. Then take that answer and divide it by 1,000 and you get 416.128482 aka 416cc. Just curious.

Jimmy

And curious you should be--You're right! I was assuming JE had calculated them correctly. 89mm was the only one I had actually done the math on when I noticed that JE and Wiseco listed their 89mm pistons at different displacements. JE was right on that one so I assumed they had them all right. Ya can't trust anyone these days!!!

After doing the math on all of them I came up with this (rounded to the nearest tenth):

85mm = 397.2cc
86mm = 406.6cc
87mm = 416.1cc
88mm = 425.7cc
89mm = 435.5cc

So, 416 IS correct and 406 is actually closer to 407 than 406....hrrmmm.

Oh well, I guess that's what I get for trying to be toooo precise!! I'll just go away now....

(thanks for pointing that out 2004exrider)

[2004exrider]

No, your posts are always expalined good and in detail. I didnt mean to come off offensive if i did. I was jsut curious if you had a different formula than i do and that mine might be wrong.:bandit:

Jimmy

[GPracer2500]

Originally posted by 2004exrider
No, your posts are always expalined good and in detail. I didnt mean to come off offensive if i did. I was jsut curious if you had a different formula than i do and that mine might be wrong.:bandit:

Jimmy

Not offensive at all. If I post something that's wrong I want to know about it so I can learn something.

:)

[Joe400ex]

Ya i have a 99 400ex. I cant wait to do a 416. I want to do 416 port and polish and cams. I already have a full LRD exsaust with the filter and jets. The motor is 7 years old. I hope i feel it, alot

Joe400ex

[rippin2]

i have a 99 and it runs jsut as good and faster then an 06 with my 416

[Green95Hoe]

My 426 continues to scare me everyday. There are a couple other things you can do as well. Look for a good Rev box to open up your RPMs and consider a 450R carb. Today I tried a 50/50 mix of 112 Octane Race fuel. It made so much more of a difference that im buying 5 gallons of it and im running straight as much as possible. Also good to keep things clean in there. Stay with an 11:1 piston and you will always have the option of running straight 93 with no problems. IMO the JE piston is better over the Wiseco because the compression is closer to what it says it is. If your gonna pull all this apart and have it done, do it right once. Re-sleeve if your going 426 or larger. Its just great peace of mind when you ride the next hot summer day. Spend the extra couple bucks on a Cometic Flex Steel Head gasket. There is nothing more frustrating that a blown head gasket. Consider your cam options too. The new Stage 2 Hotcam is an excellent all around cam. Pulls all the way to the rev limiter. Last but not least, remove the choke. All you need is a step up in pilot jet and youll never need it again. Makes a world of difference at WOT cuz there is less restriction in the throttle body. Jetting is MOST important. Too lean she will run hot and backfire. Too rich and the engine gums up with carbon as kills your gas mileage. Get that mixture just right and youll be amazed how smooth it can run. Flush some race fuel in there every so often to keep things clean. Synthetic oil is great. I personally like the AMS oil 0w40. Make sure it doesnt have friction modifiers though. Avoid the Mobil synthetics. There is a member here that deals with AMS oil. If you dont want to pay alot then get the Rotella T synthetic oil at Wal-Mart. Many people think synthetic is bad in a bike. This is only true if it has friction modifiers which cause the clutch to slip. There is still other things I have forgotten but youll find them out as you get into the project

Everyone has their opinions on the specific sizes. I have always felt that a 440 is only worth it when you go all out and replace pretty much everything to handle the power. I think if im gonna spend that kind of money id just do a 460 stroker and call it a day. 416 is great too and so is the 406. It leaves breathing room for future expansion should you choose to go bigger later. Sometimes its not all about how big of a piston you can put in there, but how efficient and tuned it is. A properly dialed in 400ex will hold its own against the big boys.

~Brad

[400exbilly]

So you guys are saying if i drag race is it better to run a 426 kit or a 440 kit thanks

[400exredrider]

If you drag race its better to have the 505ex like chads :macho

[krt400ex]

Originally posted by 400exMO
On those bores to optomize reliabilty what else should you do besides exhaust, intake, port polish, etc. Should you get new valves, or new gaskets. I'm planning on doing 416 sometime and would like it to be more reliable than the stocker. So what all should be done?

There is no way to make any modified bike more reliable than the stocker. it won't even be as reliable as the stocker with just a pipe. more pwer always puts more strain on a motor. I would get a good set of steel valves and stiffer valve springs, stronger rockers, buckets, and guides. that will certainly help, but you don't need to do this if you don't have an aftermarket cam. and you still don't need to worry about it unless the cam is strictly a mid and top end cam.

[krt400ex]

Originally posted by 440 00
this was somehelpful information for me because i bought a used bike with a 440 and did not know what gasket kit to buy

what kind of synthetic oil should i buy for my 440

Belray semi-sinthetic "thumper" oil is what I use. It's great. A bit pricy though at around $7-$7.50 a bottle.

[PowerJunkie]

ok what are the things you have to have for a 426 11.1? i know theres ppl that dont do everything and still have a relieble bike. thx

[PowerJunkie]

anyone?

[400exbilly]

So what would be better to drag race a 426 kit or a 440 kit Please replyy pleasssssssssssssssseeeeeeeee

[PowerJunkie]

from what ive heard 426 because it revs faster but dont trust me on that.;)

[PowerJunkie]

can anyone tell me?

[GPracer2500]

Originally posted by PowerJunkie
can anyone tell me?

Not really. There's nothing set in stone about 426 vs. 440 vs. whatever.

What I mean is that it just depends on the two engines your trying to compare. One guy's 426 might be faster than some other guy's 440 and vice-versa.

[PowerJunkie]

Originally posted by GPracer2500
Not really. There's nothing set in stone about 426 vs. 440 vs. whatever.

What I mean is that it just depends on the two engines your trying to compare. One guy's 426 might be faster than some other guy's 440 and vice-versa.

this is what i really wanted to know. but thnx that helped the oother guy out. heres my Q

what are the things you have to have for a 426 11.1? i know theres ppl that dont do everything and still have a relieble bike. thx

[GPracer2500]

Originally posted by PowerJunkie
this is what i really wanted to know. but thnx that helped the oother guy out. heres my Q

what are the things you have to have for a 426 11.1? i know theres ppl that dont do everything and still have a relieble bike. thx

Whoops. I got mixed up.

To respond to your question: If it was me I'd do HD head studs and have the sleeve O-ringed and call it good. YMMV

[PowerJunkie]

whats O-ringed

[GPracer2500]

Originally posted by PowerJunkie
whats O-ringed

My local builder machines a very thin groove around the top of the sleeve where it mates to the head. You take a precisely sized section of stiff wire and form it into the groove. The tricky part is keeping it in place while you install the head. The wire acts as an O-ring and creates a little bit of extra compressive force to help keep the head gasket sealed.

You'll have to ask around to find a machine shop that is familiar with that mod.

[JOEX]

Originally posted by GPracer2500
My local builder machines a very thin groove around the top of the sleeve where it mates to the head. You take a precisely sized section of stiff wire and form it into the groove. The tricky part is keeping it in place while you install the head. The wire acts as an O-ring and creates a little bit of extra compressive force to help keep the head gasket sealed.

You'll have to ask around to find a machine shop that is familiar with that mod.
Interesting :)

Is this a 'common' mod in other forms of motor sports?

[GPracer2500]

Originally posted by JOEX
Interesting :)

Is this a 'common' mod in other forms of motor sports?

I first learned of it from my machinest--he does it on his 400EX builds. I'm not sure, but I think he is more likely to O-ring the sleeve than use HD studs. When he installed my HD studs I didn't get the impression he does a lot of that [shrug].

My guess is that doing one or the other (HD studs and O-ringing) will seal up most heads adequately. I figure doing both can only help durability.

[JOEX]

Originally posted by GPracer2500
I first learned of it from my machinest--he does it on his 400EX builds. I'm not sure, but I think he is more likely to O-ring the sleeve than use HD studs. When he installed my HD studs I didn't get the impression he does a lot of that [shrug].

My guess is that doing one or the other (HD studs and O-ringing) will seal up most heads adequately. I figure doing both can only help durability.
Machining can be more art than science and each machinist has their specialty;) Nothing wrong with that:)

[GPracer2500]

Originally posted by JOEX
Machining can be more art than science and each machinist has their specialty;) Nothing wrong with that:)

Yup. This is the same guy that laser-cuts his own gaskets. :p

[PowerJunkie]

thx for the info

[IRONMIKE113]

my bike is being worked on right now bored to a 440 with 11:1 comp and a new crank i can't find hd studs no body can get them around here in de gettin a new gasket kit kibble white vavles and springs.guides ,barnett clutch kit and is there anything else im missing? :ermm

[GPracer2500]

Originally posted by JOEX
Interesting :)

Is this a 'common' mod in other forms of motor sports?

Also, I notice that Mr. Dunlop mentions O-ringing his 500 kits in his "How To" thread on boring/sleeving.

http://www.exriders.com/vbb/showthread.php?s=&threadid=221740