how to get more power from the 440?

[honduh440]

ok im wanting a lil more power i have alot of stuff done now how it is ..........440 11.1 comp, heads ported, hotcam, fcr carb, uni air filter no air box lid, and big gun exhaust. i have stock valves and have been thinkin about that but im not a mechanic so i would have to have someone do that for me does anyone know what i could expect to get in a increase with new rockers and springs? i was also concidering a 13.1 comp piston but i dont really want to pay for race gas if someone could give me some numbers on those two ideas it would be awsome or something else i could do thanks

Ok, you have everything I want. Right now I have the 440 kit, ported and polished WB slip on ground out stock exhaust and open intake lid. I havn't run it yet, but I hope it will have nice power gains over the tired old stock motor.;)

[Claas900]

..I wonder if you could get a 92mm piston? makeing it a 465 like sparks offers..or can u not go over 440cc's?..maybe even on pump gas?..

[SnellCRP]

With your current combination, 440 11.1 comp, heads ported, hotcam, fcr carb, uni air filter no air box lid, and big gun exhaust. My first question is who ported the head and was it done on a flowbench? Head porting can lose power if not done right. The idea is to flow the max volume of air through the smallest port which maintains velocity.

You have some other options that may require the use of race gas, but just do one at a time and listen carefully for "pinging". You may not have to run 100% race gas maybe just a % mix to stop the "pinging".

First: If you haven't had the quad tuned on a dyno you will pick up some HP/Torque just from getting the carb tuned in right. You can't really tune it with "feel" or plug color. Have it dialed in on a dyno.

Second: If you have the motor apart either reassemble with thin gaskets or have .030 taken off the base of the jug and run full gaskets. This will bring your squish band down to where its should be. Between .030 - .040. depending on your gasket thicknesses and whether you are running a stock rev limiter or no rev limiter. If you are running stock you can get the squish down to around .030, but if you aren't running a rev limiter if you ever miss a gear or just overrev you will take the chance of the piston hitting the head (you will get some rod stretch) if your squish is around .030 so keep it above .035 with no rev limiter. This will bump the compression and make the motor more efficient.

Third: You could go with a "aggressive" CDI that changes your spark curve and go with a 6 degree flywheel key. You will pick up HP/torque along with improving throttle response.

Fourth: You could have the flywheel lightened. This dosen't make more power it just lets the engine get into the powerband quicker which makes the quad quicker. It also reduces rotating mass which can cause the bike to stall easier when trying to "lug" it.

Fifth: You could do a stroker which will increase displacement, but could make the motor not rev as high and if you have a stage 2 cam its possible because if the longer duration required on the cam to make higher RPM HP it would could kill the low RPM cylinder pressure which is where the stroker likes to make power. You will pick up good power increases with a stroker and the right cam in the low - mid area of the powerband.

Rocker arms and springs will not increase power unless they decrease valvetrain friction and I don't think they are making roller rockers for quad motors yet so I wouldn't count on those to make power. A thicker hard facing on the rockers would increase longevity of the rockers and stiffer springs would only benefit you if the cam required it. Mods 2 & 3 may require race gas, but the others won't. You will just have to decide how much power you want and what you are willing to sacrifice to get it. ;)

[honduh440]

what could i expect going to a hi comp piston like 13.1?

[Bean]

you could get a more aggressive cam, slightly larger valves, better valve springs, and a 3 angle valve job, that would pull some more ponies out of there, a less restrictive exhaust also

[honduh440]

what kind of cdi box should i get? and what is a 3 angle valve job and what does it usully cost

I have the three angle valve job on my new 440. My mechanic mad 3 cuts on my valve seats. I believe they were 40 degrees, 60 degrees and 80 degrees. The 60 degree cut is the only one that makes contact with the valve. If this cut is extremely thin, it will decrease the chance of carbon building up on the seats which will allow your engine to run longer between rebuilds.