416-426-440????? what is best

[sweet t-rex 400]

I have factory bore at 85mm right now. Im about to rebuild but want more power:devil: Im a trail rider but run a lot on the drag strip at busco beach. I have a K&N filter with full curtis sparks pipe and jet kit. I have a stage two magnum cam and monster coil with rev box. What would be my best choice for my riding condition. I pound the hell out of that thing also so i need reliability. I heard the 440 runs hot and is for holeshot. 426 runs good with more top end than 440 but i could have heard wrong. I also dont wanna buy a new sleeve but will have machine shop bore it. What is the bore size of the cylinder for each of these. I know its a lot but wanna do it right the first time! THANKS

[JOHNDOE83]

440 is best regardless, I have no heat issues.

There is no difference in how fast it revs.

People are gonna disagree and thats fine, but facts are facts.

[01boneless]

a good realiable quick set up is 416 11:1 wiseco piston (bore is not where the powwer is its all in compression) stage 2 cam hd head studs cometic gaskets and a spal fan same setup on the 440's and 426's exept on them you MUST run a spal fan AND oversize oil cooler

[JOHNDOE83]

I dont use a fan or a bigger cooler and I still have no heat issues.

[01boneless]

^^ WOW you must be very lucky then cause every 400ex member on here will say there NEEDED. but i guess thats good on your part

[sweet t-rex 400]

What is the bore size for a 416? Factory is 85mm and a 440 is 89...i think 426 is 88...what is a 416...i think im goin with that

[sweet t-rex 400]

i think i got it...its 87 right? So i just have the machine shop bore the stock sleeve to 87mm right then get a 416 11:1 wiseco piston. Also get hd studs and spal fan right?

[Stickman400]

Well, my 407 is an 86mm, so using those numbers one can only assume it's an 87mm. You need to get the piston and bring it to the machine shop so they can match the piston to the cylinder. And yes, get the studs and the fan.

[400exrip]

I have a 440 in my race bike and do not have any overheating problems either, And do not run spal fan or bigger oil cooler.

But I guess it is because I run 110 race gas and a good synthetic oil, And it keeps the motor cooler.

[powerbomb400]

I got a 88mm which a 426cc. I went with the 10 to 1 compression. We ride alot of miles and do little of everything. I run a stage 2 HotCam and didn't go with higher compression cause I was worried about the heat build-up. Also the higher compression wears more on the head.

[Longdong]

Originally posted by sweet t-rex 400
i think i got it...its 87 right? So i just have the machine shop bore the stock sleeve to 87mm right then get a 416 11:1 wiseco piston. Also get hd studs and spal fan right?

With that setup you will not need hd studs.

[CJM]

Originally posted by Longdong
With that setup you will not need hd studs.

For cheap insurance its worth it, once you jet the bike improperly or have a heat issue the studs near the exhaust will pull out.

Spend the money wisely imho, but for 100 bucks its worth it (cost to buy and have GT Thunder install them)

[ridinwide02]

Originally posted by 400exrip
I have a 440 in my race bike and do not have any overheating problems either, And do not run spal fan or bigger oil cooler.

But I guess it is because I run 110 race gas and a good synthetic oil, And it keeps the motor cooler.



my bike was a 440 when i got it and it ran on pump gas and it dont have a fan or bigger cooler. it is now in progress of a trbuild and getting a 426 my 426 piston is a 86mm

[JOHNDOE83]

Overheating is caused by improper jetting or a equipment failure.

I do notice slightly cooler temps when I run 110 octane, my 220 main jet plays a role in my cooler temps also.

I did this 440 build 6 years ago, still runs like a new build, I cant remember if its 10:1 or 11:1.

HD studs arent nesescary, but like CJM said they are a good thing to have for piece of mind.

[trailrider894]

Originally posted by JOHNDOE83
440 is best regardless, I have no heat issues.

There is no difference in how fast it revs.

People are gonna disagree and thats fine, but facts are facts.

There is no " best " bore size... 440, 426, 416, 406... its all a matter of a few HP difference. You may not experience any heat issue's yet, but i'm sure you suffer from some heat fade. I would recommend that anybody even with a stock engine, to install a secondary cooler or oversized oil tank. As far as revving faster, the best thing you can do is lighten the flywheel.

[CDCHONDAS]

First off I am from Pennsylvania so you know what my climate is. I have never ever had an issue with anyone's 440 that I built overheating. I've never had oversized oil coolers or fans. I had not even heard of the fan thing until I just read this today. I probably haven't read this site in a few years so maybe that is why. A 440 will rev slower, it does make nice torque but it will rev slower, this is mathematical fact. If you do a carb and porting and the right things a 440 can be a decent animal. However the juice is not worth the squeeze anymore. Why go to the trouble and money when you could buy a 450 and be miles ahead? Basically the only "hi-performance" 400 ex I do anymore is 87 mm and 11:1 piston. studs are not a requirement but are money well spent. Typically I will do a fancy valve job at the time to work on the seat angles and maybe a quick blend here or there on the ports, nothing more than 5 minutes worth. I use metal gaskets straight from cometic. 87mm at 11:1 is just enough bore/compression to build some power but mild enough to not have the baggage that comes with a 440. I have had great feedback over the years with that engine package.

[honda400ex2003]

Originally posted by JOHNDOE83
I dont use a fan or a bigger cooler and I still have no heat issues.

x2, wasnt over 200 degrees all summer riding my 440 hundreds of miles. jetting is key, after that its all good. i ran 180-190 regularly.

for a good budget build the 416 is probably the way to go.

all out torque and power 440 or a stroker setup with a 416 piston. my 440 is a blast to ride esp with 20s and 15/38 gears.

i enjoyed the 416 10:1 comp with 6 degree key and stage 1 alot, it felt similar in power band execution to my 440. the stage 2 in my 416 with my 450r carb was a mid range setup for sure.

my 416, 1 and 2 hotcam, 6 degree cam ran about 200-205 degrees all the time and would get 220 when ridden hard
3 degree key was about 195-200 daily and ran 215 hard for a while.

I monitor my temps on oil with an xrs only dip stick and monitor it every ride every few miles through the whole day.

i had thousands of miles on my 416 piston, i bet i had 4 thousand miles on it at least over 3 years.
I have 600 or so on my 440 piston now for comparison purposes with 1 summer on it.

440 FTW if you have the coin for the sleeve and such.

steve

[djwilliams0822]

Get a 440 it shouldn't over heat but I have a spal fan on my stock cooler and an oversized oil cooler just to keep the temps down.

[powerbomb400]

The 110 octane burns colder than premium unleaded. It helps keep ours cooler in the summertime. Keeping your oil changed also helps. A good oil that resists thermal breakdown also helps.

[sweet t-rex 400]

i made the choice...416 all the way. Whats the best jet size for it. Not sure what i got now but it runs hot already. Got k&n filter and curtis sparks pipe and stage 2 cam equal to stage 3 hot cam. Didnt know if that makes a difference.

[djwilliams0822]

You said your choice is 440? Ha not 416?

[CJM]

170 main should be about ball park.

[2muchquad]

everybody has a opinion.the 400s like a bit of compression regardless of bore.Youll want a 11 to 1 piston if you go with a stg 2 or 3 cam from hot cams.A fcr carb works killer on these bikes too from my experience.Guys have had success with the 04-05 450r carb too.I plan on doing the 88mm 13 to 1 set up this winter just because my last few 400s have been "safe"builds.Its time to up ante a lil'bit.Being old skool compression is where you start to make your power.;)

[sweet t-rex 400]

going with the 416 11:1 wiseco hd studs and 170 main jet...final answer...will post results after christmas. Thanks too everybody and thanks a lot to CMJ

[sweet t-rex 400]

Thanks CJM

[CJM]

Your welcome, good luck with the build.