really that big of a difference between 406 and 416?

[ranger400ex1994]

well i got a ross 406 pistion from cal for pertty cheap is 10:6.1 compression. but i would really like to know if there would be that big of a difference in power between a 406 and a 416 with about the same compression and a stage 2 hot cam. i just want to get some extra power to compete more with 440exs and both yamaha 450s and honda 450s. i know i wont take them in drag races and stuff like that but thats not how i race. i race MX more on 3 pretty tight tracks so top speed is not a big deal. really what i am woundering if i should stick the money and build a 406 for cheap then eventully up grade to a 426 or more likely a 440kit. or should i just save and build a 440kit right now or a pretty good 416.

[Toadz400]

I don't know if there is a big difference between the 406 and the 416, but a 416 with stage 2 cam, full exhaust, 39mm carb and porting is a HUGE difference between stock with exhaust. I'd say just go with the 416 and you could probably just stay with that as long as you know how to ride right.

Ah you're from Wisconsin...lets go riding:D , I'm bored out of my mind!

[Kilabanshee]

Yeah my worked 416 can beet some very nice 440ex's. I have porting, valves, carb, pipe ect going with it soo yeah I know you will deff people able to keep up with the 440s if you have a nice setup.

[ranger400ex1994]

also i am building this motor to be more for reliablity then power but if theres not that big of a difference between a 406 and a 416 then i will just build the 406. i rode one 406 and i loved how fast it reved it was in pressed.

[TC426EX]

Just go with the 416 or 426 man. I beat 440's and 450's with my 426 all the time on tracks. I cant holeshot every moto like I used to, with the 450's but once the initial drag race at the start is over I can keep up fine around everything and let the remainder of the race come down to rider skills. Thats not to say I never can holeshot, I have a couple times this season, but the 450's are FAST off the jump in a straight line. Either way you will be competitive and be able to hold your own in the top positions as long as your rider skills are up to par with everyone else in your class. Some people will tell you "go with the 406 and then save yourself 2 more bores on the stock sleeve"... I dont agree because its not like re boring your ex is a regular thing or anything... With the 450's out you want to definitely go with the maximum displacement possible. Now I would say 426 is the best size since it is the biggest bore on the stock sleeve and revs much faster than a 440. A built 426 or even a built 416 CAN hold its own and beat a 440, especially in the tight stuff where acceleration and midrange is the order of the day....

[Toadz400]

Originally posted by TC426EX
Just go with the 416 or 426 man. I beat 440's and 450's with my 426 all the time on tracks. I cant holeshot every moto like I used to, with the 450's but once the initial drag race at the start is over I can keep up fine around everything and let the remainder of the race come down to rider skills. Thats not to say I never can holeshot, I have a couple times this season, but the 450's are FAST off the jump in a straight line. Either way you will be competitive and be able to hold your own in the top positions as long as your rider skills are up to par with everyone else in your class. Some people will tell you "go with the 406 and then save yourself 2 more bores on the stock sleeve"... I dont agree because its not like re boring your ex is a regular thing or anything... With the 450's out you want to definitely go with the maximum displacement possible. Now I would say 426 is the best size since it is the biggest bore on the stock sleeve and revs much faster than a 440. A built 426 or even a built 416 CAN hold its own and beat a 440, especially in the tight stuff where acceleration and midrange is the order of the day....

I completely agree with TC, go with the 416 or 426. If you are worried about having a bore left, go with the 416. If you definately want the most out of it, get everything that can be done with the engine. The bigger carb definately makes a huge difference too! That was night and day, I rode my friend's 416 before and after he put the 39mm carb on, afterwards it felt like he added a 416 kit again.

[04'400ex'er]

The 406 won't beat a 440. The 416 might. Most 440's will have a hotcam in also, or at least a hotter cam than stock, so you will prob need more to pull them. If I were you, I would send the piston back and get a 416/426 and get a port job on your head. Keep in mind the stock rod will be fine on the 406, but I wouldn't trust it on the 416. If you really want to rip, Check out the 416 national kits from TC and Sparks. Also, what type of piston?

[ranger400ex1994]

well i can't really send it back i bought it from the member cals400ex so i guess maybe i will just try to sell it or just put it in and see how i like it.

[INFANTRY RACING]

the 406 will be fine. it's the compression that make the big difference not 10 cc's

[cals400ex]

i don't see how it would be possible to have a noticeable difference in power with going 1mm larger?? when i bought the piston, i was told that i wouldn't be able to notice a difference in power between the 406 and 416.

however, i don't have a 416 to compare. my buddy will have his 416 in a week or two and i would be able to let you know then. there is no way i would go out and buy a new piston just 1mm larger than that 406 that you already have, especially with the good condition that it is in.

[ranger400ex1994]

ya cals tell me how his is when he gets it done. i know i got your 406 now but i'm sure you can still kinda remember how it felt. just either post it on here or leave me a message.