440 Big Bore Ratios????

[Hondahillbilly]

What is the difference in these two 440 bore kits? There is one that is saw that was 11:1? and one that was 12:5:1? I don't understand this?

[DementeD]

its the compression ratio..imo id get the 11:1 the higher the comp the higher octane gas u have to run and 12.5:1 is definitely needing race fuel where 11:1 may be plausible on 93octane..

not an expert just throughin around what ive seen/heard

[Hondahillbilly]

thanks. but do they make the same amount of power for the most part?

[2muchquad]

generally speaking,4 strokes make their power through higher compression.This is just a rule of thumb but not always.The lower compression kit can make more power than the 12 to 1 kit depending on the set up.An engine is like a system,the intake,cam,carb fuel mixture,exhaust everything has to be able to work together to compliment each other for the highest possible effficieny and not just a assortment of mix and match parts.But in a nutshell,its possible to get more performance from the 12 to 1 kit if your willing to run higher octane fuel and you'll run the correct camshaft that will work with the set up.The higher compression will piston will need larger primaries on the exhaust as well,this means a aftermarket full system as well,otherwise temps will get outta control,which is another whole issue;)

[DementeD]

^ pretty much what he said

thats why i suggested the 11:1..itd just be easier on u and can still make great power


its just a lot easier on urself and the power honestly isnt that big of a loss..ur bike will still be fast and lot more reliable and cheaper to build..

[atvhonda-rider]

i wouldnt go 440 period... you can make the same amount of power with a 416 11:1. its all with your setups as seaid above. a 440 kit with a hotcam no port and a slip-on exhaust would get smoked by a 416 with a hotcam, port job and a ful exhaust tuned right.. and this goes for all kinds of combo's and tunings.. just gotta know how to build it for what price your looking to spend

[TRXRacer1]

Originally posted by atvhonda-rider
i wouldnt go 440 period... you can make the same amount of power with a 416 11:1. its all with your setups as seaid above. a 440 kit with a hotcam no port and a slip-on exhaust would get smoked by a 416 with a hotcam, port job and a ful exhaust tuned right.. and this goes for all kinds of combo's and tunings.. just gotta know how to build it for what price your looking to spend I think "smoked" is a bit extreme and if you build that 440 with a port, hotcams, bigger carb and exhaust it's going to have more power then the equally built 416.

[DementeD]

^ Thats exactly what i plan to do ..its just hard to find "evidence" of this stuff

its all hearsay so far..

i build computers and have worked on plenty of honda cars made fast and understand them and know what works great for them

these 400ex's...i cant find enough proof behind what people say

i mean its hard to go by..oh yea my 426 takes 450s all day...

ok why? does it really have better power or is the rider on the 450 just that much garbage..

thats my biggest issue so far..being as i havent done much im just tryin to do small things to mine..leaving it a stock 400
im addin the timing key probably a rev box soon and a cam for now
i think that will be good for the time being then eventually a 416 which i still might not raise the comp that high so i can still use the timing key


id like to find out if..say a 10:1 with the key on a 416 would be ..more beneficial over a 11:1 without the key ..since i know there is a limit on how high comp with the timing key..

[bearair]

I've got the timing key in mine and I don't think I'd run a rev box in addition to it. A lot of the rev boxes have an ignition timing advance function along with a higher rev limiter. some are 3-4 degrees and that would be a bit much with the key.

I'm currently running a Curtis Sparks timing key, Curtis Sparks air filter with boot insert, six 1 1/2" holes in the rear half of the airbox lid, header pipe welds ground down and polished, Lexx silencer and a Dynojet kit. I'm using the 146 jet and it looks to be spot on for the altitude. I can definitely say that for not a lot of money the power is a LOT better and more useable than the stock configuration. Pulls right from the bottom and throttle response is immediate. I'm probably going to leave it alone until I need to replace something and then I'll go larger. For right now it's quick enough to be a lot more fun and the suspension needs to be finished before I even need to think about more power.

[DementeD]

well i was lookin at the CS rev box which they claim works great with the key..who woulda thought? haha

anyway im ...a lil sketchy of drillin holes on the airbox lid since i dont want to run into problems with dust gettin in my carb etc..

i run a k&n..maybe if i run an outwears with it that may not be a bad idea..idk id probably have to rejet as well..


is there a topic about grinding the welds on the header down?

i may do this when i wrap it..

[2muchquad]

thats my biggest issue so far..being as i havent done much im just tryin to do small things to mine..leaving it a stock 400

Thats how mine is so far.I have a slip on and a k and n air filter with no lid.It runs pretty good so i havent even opened the motor up yet,which is rare for me.Once i do im planning on a 416 with a 11.5 to 1 piston or so and maybe a drop in cam along with the fcr i got for it and that'll be it.Its got all the power i need now for play riding,no need to get carried away.;)

[bearair]

Originally posted by DementeD
well i was lookin at the CS rev box which they claim works great with the key..who woulda thought? haha

is there a topic about grinding the welds on the header down?

i may do this when i wrap it..

The Curtis Sparks rev box is just increases the rev limit if I remember correctly. No advance funtion.

There is a good topic on grinding the header. Here's a pic in this thread http://www.exriders.com/vbb/showthread.php?s=&threadid=334681&perpage=13&highlight=grinding%20welds&pagenumber=2

Here's a how to with pics http://www.exriders.com/vbb/showthread.php?s=&threadid=334885

[400Trooper]

Not to start an agrument but I think you need to define what you plan to do with your quad.

400, 416, 426, 440 whatever, if you plan to race, suspension should be the first priority IMO. The 400 is pretty quick but has poor suspension. If you have a "stock" 400 with plenty of "correct" suspension you will be faster than a guy / girl with a modified engine 400 with no suspension upgrades.

Anyone can go fast on a straight, smooth path. Now add in whoops, jumps, turns, g-outs, square edges and see who is faster!! I can almost guarantee a "416" with no suspension will get "smoked" by a 400 with a long travel suspension set-up, IF, and I repeat, IF the riders are of equal riding ability!

[Hondahillbilly]

So I don't ride competitively. I just was having thoughts about it I bored it as big as they make it, and my buddies and I are riding around on trails and we get on a straight gravel road I can just open it up and just take off on them and when they catch up just laugh because they can't ride with me if I don't want them to. Simple as that. I just want it to top out as fast as it could, but still be a trail bike.

[upyours]

Originally posted by atvhonda-rider
i wouldnt go 440 period... you can make the same amount of power with a 416 11:1. its all with your setups as seaid above. a 440 kit with a hotcam no port and a slip-on exhaust would get smoked by a 416 with a hotcam, port job and a ful exhaust tuned right.. and this goes for all kinds of combo's and tunings.. just gotta know how to build it for what price your looking to spend

ill have to go with you on the 416 mine is a ripper i race my 450 now but i raced my 400 until last year and was doing pretty good on it till the trans came appart but i had a web cam big valves an port job but do yourself a favor and use hardface rockers if you change the cam if not if your hard on it youll burn out stockers it doesnt matter if it says you dont have too if you run it hard they will melt with any aftermarket cam but my 416 beat my buddies hrc kitted duncan exhaut 450r till 4th gear then we stayed even till 5th and ran into a turn but mine was set up for low and mid range and it pulled were expected

[TRXRacer1]

Originally posted by upyours
i had a web cam big valves an port job but do yourself a favor and use hardface rockers if you change the cam if not if your hard on it youll burn out stockers it doesnt matter if it says you dont have too if you run it hard they will melt with any aftermarket cam Not entirely true. Yes you need hardened rockers for a webcam but that's because it's a hardweld cam...... a regrind. The cam then becomes way harder then the stock rockers. This is not a problem with hotcams. You don't want hardened rockers near a hotcam at all. Then the rockers will eat up your cam. You need to match the materials.

[upyours]

Originally posted by TRXRacer1
Not entirely true. Yes you need hardened rockers for a webcam but that's because it's a hardweld cam...... a regrind. The cam then becomes way harder then the stock rockers. This is not a problem with hotcams. You don't want hardened rockers near a hotcam at all. Then the rockers will eat up your cam. You need to match the materials.

dude it was a problem for me with hot cams i ate up both my stock exhaust rockers with a stage one hot cam the second time i had it out and it ate up the cam lobes as well thats when i took hot cam out and put web in so i had to rebuild my head again and i said hell with it and went big valves and just for referance my valves were adjusted to what ever it was that hot cams said to adjust them too (i dont remember what it was that was like 4 years ago) so just food for thought