416,426 or 440

[moshachusetts]

i want more power out of my 400 so i'm looking to get the motor built. my question is what are the pro's and con's between the 416,426 & 440 ? reliabilty, is the more machineing involved? if you blow the 440 do you need a new cylinder or just a sleeve? i'm just looking for more power for my woods bike. since i've gotten my yfz450 i use that for both xc and mx just beuase of more power. i'm looking for a comparable power for my woods bike so i can keep my yfz setup as my mx bike

thanks in advance for your help

[bbender85]

everyone will say 416, for the simple fact that you're not all-in on your bores (you blow your 426 or 440, you need a new sleeve). go with a higher compression piston and head studs, then any supporting mods you want depending on budget... and you'll be good.

[moshachusetts]

what other mods would you suggest?

[matt14c]

416 or 426. Ross used to make a sleeve that you put in for the 426 that if you blow it then it can be straight bored to a 440 without another sleeve. With all of them you will want HD head studs, prolly replace your timing chain with a crf chain, new tensioner. You will want at least a slip on and for the 440 I would have to say you will need a full system. For the larger two you will want something for extra cooling. Either another oil cooler or spal fan. Larger carb will help them all. and of course aftermarket air filter.

[flyboy1294]

Originally posted by moshachusetts
what other mods would you suggest?

If you get the engine built, I would definitely recommend a cam. It helps bring out some extra power. And 450r carbs help quite a bit also, and maybe one of those +3 or +4 timing keys Wheelie makes. I haven't tried one personally but I've heard good things about them. With a built engine the curtis sparks +6 key can cause spark knock.

Also an exhaust, and K&N filter for certain.

The cam is going to run you around $125, the 450r carb is $160 NEW, and the parts you need to install are appox. $75 (Zrpilot's adapter, Yfz throttle cable), and the timing keys are around $25.

So for all those engine parts, $275 plus the exhaust and filter, along with whatever you spend on the build. Those are fairly cheap mods, and all make a very big difference.

That's my 2 cents...

[killer400ex]

i think that the 426 is a good choice because it revvs quicker than a 440 but it produces power close enough to the 440, yet you still have the choice to bore up to a 440 if you ever want to, and if you do go with a 440 then you have a higher risk of overheating because the sleeve is pressed in instead of having the cylinder molded around the sleeve. i love my 426 and i have ridden a few 416 and 440's and i think that the 426 is the best of both worlds, i also bumped my cam up from a stage 1 to a stage two and i am extremely happy with it, orrigonally i had the stage 1 with a 406 11:1 wiseco and it was great because the stage 1 gives it alot of bottom end power and the 406 still revved like crazy, but with the 426 11:1 and the stage 2 with a full exhaust it is nastier than most machines around here, in the woods and on the track or at the dunes, trust me you wont be dissapointed

[honda400ex2003]

If it was me i would try a 426 12:1 and a stage 2. Add a nice port and polish. and a nice exhaust to it to finish it off. i love my 416 too though how it is set up so if i could find a new cylinder with a 416 in it i would think about doing it again. i guess it just depends on what yoy want to do. steve

[bbender85]

Originally posted by killer400ex
...and if you do go with a 440 then you have a higher risk of overheating because the sleeve is pressed in instead of having the cylinder molded around the sleeve.

thing is tho, with a 426, the sleeve is so thin from boring it so far that it runs the risk of heat too. i run a 426... the only reason i didn't do a 416 was because the guy told me it had a bore kit in it already, so i went big.

like i originally said, i'd do a 416, then still have the option to go 426 down the road, without having to re-sleeve, if it needs another top end while you own it; if you build a 416 and a 426 with the same mods, i bet you wouldnt be able to tell a big enough difference to make having to re-sleeve the next rebuild worth it.

[killer400ex]

Originally posted by honda400ex2003
If it was me i would try a 426 12:1 and a stage 2. Add a nice port and polish. and a nice exhaust to it to finish it off. i love my 416 too though how it is set up so if i could find a new cylinder with a 416 in it i would think about doing it again. i guess it just depends on what yoy want to do. steve

idk about the 12:1 i mean yeah you could do it but then you would definitely have to put in hd head studs and you have to run race fuel all the time, at least with a 11:1 you can run pump when you have too without running the risk of detonation

[moshachusetts]

Originally posted by killer400ex
idk about the 12:1 i mean yeah you could do it but then you would definitely have to put in hd head studs and you have to run race fuel all the time, at least with a 11:1 you can run pump when you have too without running the risk of detonation

yeah i definetly want to stay with pump gas and still want to keep the bike reliable.

[honda400ex2003]

you asked what you could do to get the most power so i told you something that would give a very nice bang for your buck. That would be a dream type 426. i would do an 11:1 since it is much easier to get 91 or 93 instead of racing gas. As you can see i only have 10:1 since i can not always get 91 on trails that i ride. if i carry some 91 or 93 then it is not bad but you never know. steve

[moshachusetts]

thanks everybody for their help. probably gonna go with the 416 and a cam,head studs and heavy duty cam chain, maybe the 450r carb too since its pretty cheap. thinking about having DRT motorsports do the work since i dont have the time or skill to do it. so i'll also get his opinion on things as well. thanks for all the suggestions

forgot to mention, already have a hmf full pipe and k&n filter

[honda400ex2003]

Sounds like a great setup, what cam do you plan to run with the hmf full? steve

[F-16Guy]

Originally posted by killer400ex
....you have a higher risk of overheating because the sleeve is pressed in instead of having the cylinder molded around the sleeve...

The stock sleeve is installed just like any other sleeve; the cylinder is not "molded" around it. The cylinder is cast, machined, and bored to accept the OEM sleeve.

[jak1389]

.

[Wheelie]

I'll take a 440 stroker over a 416/426/440 big bore any day of the week.

[moshachusetts]

Originally posted by honda400ex2003
Sounds like a great setup, what cam do you plan to run with the hmf full? steve

no clue, whoever i get to do the motor work, i'll see what they suggest as i know nothing about them

[moshachusetts]

Originally posted by Wheelie
I'll take a 440 stroker over a 416/426/440 big bore any day of the week.

whats the difference between the stroker and big bore?

[Wheelie]

My stroker setup is a 416 piston with a +4mm stroke.

Stock is 85x70mm

440 stroker is 87mmx74mm.

Most 440 big bores are 88.5 or 89mm which is actually 430ccs or 435ccs.

The 440 stroker is more expensive than a big bore, but it will be more reliable and make more power.

[sab24711]

just cram as much air as you can in the motor
more air = more hp