the most reliable kit 408cc 416cc 426cc 440cc 465cc

[ThorRacing37]

what do u think the most reliable kit is i would be racing MX and dont feel like have the rod going though the cylender.... or have the the engin wall to thin... so let me know what you guy/girls think.

[jordan_m6]

they are all reliable if done right. but if you only want to change the bore than you can go up to a 440 11:1 with out changing the rod, or valve springs. i may be wrong.

[ThorRacing37]

i was thinking about getting a 440 kit if i did would i need a long (+4mm) crank? and what compresion is good and what gas should i rum in it

[440_Turtle]

No you will nto need a longer rod, your only changing the bore size not the stroke. personally i woudl go with a well built 416 or 426 with a nice cam to match. They are very fast revving and powerful engines.

[underpowered]

Originally posted by ThorRacing37
i was thinking about getting a 440 kit if i did would i need a long (+4mm) crank? and what compresion is good and what gas should i rum in it

it depends on how you want to 440 it. you could go with a straight bore 440. it a new sleeve and an 89mm piston to achieve teh 440. you could also do a +4mm stroke crank and a 416 bore (87mm piston) to get a 440.

For compression, it depends on the willingness and availability to run race gas. if you want to run pump, stay at or below 11:1. anythig above that and sometimes including 11:1 requires atleast a mix of race fuel, if not straight race gas.

As far as teh best bore, i am not a fan of the 440. i like a 416 and a 426 much better than the 440. It is up to you but i would say to go with a 416 to save a bore and give you a little extra wall thickness.

[jsmith2232]

I went with the 416 and I can keep up with alot of z's, 440's and stock 450's, plus it revs very freely and pulls hard through all the gears.