motor build ?

[tx07400ex]

Ok so im probably fixing to turn my 400 into a 416, I want to go as high as i can with comp. w/o going to race gas i know most of yall say 11:1 is the highest but also w/ comp. loss from a sg. 2 hotcam and stock head gasket would a 12:1 lose enough compression to run on 93 octane if not ill just go 11:1 and come out somewhere short of that

[hypersnyper6947]

Originally posted by tx07400ex
Ok so im probably fixing to turn my 400 into a 416, I want to go as high as i can with comp. w/o going to race gas i know most of yall say 11:1 is the highest but also w/ comp. loss from a sg. 2 hotcam and stock head gasket would a 12:1 lose enough compression to run on 93 octane if not ill just go 11:1 and come out somewhere short of that

Most likely you will be fine but its kinda a gamble. Race fuel from sunoco here is like $7.99 per gallon, you may have to just mix 50/50 with the 110 and 93. Higher compression also brings on a bit more heat, so if you ride fast trails or fire roads you'll be good but if you ride tight trails which tend to be slower you may want to think about alternate ways of cooling ie. bigger oil cooler, bigger oil reservoir and or a fan.

[droppedmazda]

run a 12:1, ive got one and i dont run race gas all the time. it runs fine on 93 octane. only race gas that i have seen run hot is oxidated race gas. i will not run oxidated fuel in my bike. race gas here is $5.20 so i do run it some and i love it. but 12:1 is a great piston i think.

[tx07400ex]

i do tend to ride slow trails alot most of my friends ride 4x4 so they cant hang with me even if i was stock, the few that do have sport bikes are almost all 450s and i want to be able to hang with the stock ones i know some of them ill never catch, the main reason i dont want to run race gas is the only place near me to get it is about 45 miles away and i ride too often to drive that far for gas, i know when i bore it i need to go to hd studs and ill probably get a hd cam chain too but do i need to change the rockers and valves/springs too

[droppedmazda]

you dont have too but it would be a nice upgrade if your gonna get a cam.

[tx07400ex]

yeah if this job i just started works out the way its supposed to ill have enough to go ahead and do everything if not well it might all be put on hold for awhile, if it works out though its gonna be motor, nerfs, bumper, tires, maybe elkas and +1s

[400exrider720]

Maybe this is a stupid question, but why don't you just save the money and sell your 400 and get a 450? If you really want to keep up with a 450, get a 450.

[tx07400ex]

well there are a few reasons, a) i just paid off my 400 b) imo the 400s are much tougher and lower maintainence c) i can already beat my buddy on his kfx450 through 4th then he finally passes me, plus like my buddy with a trx450r said 400 parts are a dime a dozen