440 or 416 kit?

[a_mounty]

i was looking at the 440 and the 416 kits for the 400ex and i was wondering what has to be done for each and if they have a great deal of power increase and stuff like that?

[cals400ex]

i would go 416 if it was me. with a higher compression piston, new cam, and a full exhaust you will feel a drastic gain.

[CHEVYZ]

For both of them, the only thing "Necessary" is to get it bored, resleeved, and get the piston and gaskets of your choice. For both I would recommend other componets along with the kit... cam, exhaust, airfilter if you haven't done them already. It is your choice as to how far you want to go with that. The 440 generally requires more things to keep up with your reliability and durability.... heavy duty studs, timing chain, ect. ( There is a great deal as to what you can do for this also.... it just depends on how far you are willing to go). If you go to the 400EX forum, there are already some threads to let you know ALL of what you should get for performance and durabilty concerns. Another good thing of recommendation that you get for both is a good carb ( Especially for a 440) and head work if you are really looking to get the most out of it. Both can give you really good results when done right. Some say the 416 revs faster, the 440 produces way more torque ... both have good power all around, and both do very well over stock.

[a_mounty]

i know what resleeved is but what is the boring ?
does that mean i have to make the cylinder bigger?
if so how hard is that and how can it be done

[a_mounty]

another ? i have is about the hot cams stage II.
does it require anything besides the cam and whatever comes with it, or do i have to by new valves and timing chain and a bunch of other stuff?
how much does this help hp?

[CHEVYZ]

Yes, when you bore it out, you are going to bore ( Or yes, make larger- inside.... for example, a stock 400EX is 85mm, and a 440 is 89mm) your cylinder. For this, you will need to send it out to someone to have it done. Should cost between $30.00- 60.00 depending on where you get it done. For the Hotcam, you do not have to get anything more- it is a drop in cam. A cam helps alot with power. The main things that you will want with a big bore kit would be exhaust, airfilter, a cam, and whatever else is necessary for what you will be running- for example, jets if you run a stock carb or one requiring them. Other things are up to you depending on budget and what you will be running.

[prepracing]

Originally posted by CHEVYZ
For both of them, the only thing "Necessary" is to get it bored, resleeved, and get the piston and gaskets of your choice. For both I would recommend other componets along with the kit... cam, exhaust, airfilter if you haven't done them already. It is your choice as to how far you want to go with that. The 440 generally requires more things to keep up with your reliability and durability.... heavy duty studs, timing chain, ect. ( There is a great deal as to what you can do for this also.... it just depends on how far you are willing to go). If you go to the 400EX forum, there are already some threads to let you know ALL of what you should get for performance and durabilty concerns. Another good thing of recommendation that you get for both is a good carb ( Especially for a 440) and head work if you are really looking to get the most out of it. Both can give you really good results when done right. Some say the 416 revs faster, the 440 produces way more torque ... both have good power all around, and both do very well over stock.


It is not "Necessary" to resleeve for a 416

[CHEVYZ]

Ooops, you are correct... I was thinking more along the lines of the 440 in my mind. Dee dee dee. :uhoh:

[honda460ex]

Me personaly, go with the 440. If you are looking at purchasing the Stage 2 Hotcam, you want to definately go with the 440. I'm speking from experience here. See, you get torque out a 400ex in two ways, either A.)Larger Displacement, or B.)Higher Compression Ratio, or both. You want it to be real torquey, go with both. BUT, back to the cam.... That cam is designed for a mid-upper power range. Your low end power will suffer drastically if you go with the 416. My honest suggestion if you are looking for reliabilty and long term riding, buy a 426 kit. I'm not sure the maker, but there has been a company that has come out with a 426 sleeve that can be bored out to a 440. So in other words, you won't have to replace the sleeve when you rebuild it the first time, just go with a bigger bore. My friend Tyler has a 426 with 10.8 to 1 compression and a stage 2 Hotcam (used to be in my quad, I gave it to him, I've got a stroker motor and cam now), HMF slip on exhaust, and that thing runs really awesome. But I would not recomend going any smaller than a 426 with that cam. Or else you will be kinda riding it like a 2 stroke in a way, no bottom all top. His quad has a very smooth power band that is pretty even through out. If you want some ideas on combos of parts or what you need, let me know. I've rebuilt mine three times as well as two other peoples 400's.

[81 clark racing]

i have a 400ex and im looking to bore it out. what do i need to up grade if i bore it an what should i bore it to a 416 426 or 440? have full big gun exhaust white bros rev box stage 1 or 2 hot cams not sure snd a jet kit. do most fast trail riding, trail racing