426 or 440 or 460

[yamahamx14]

Hi. Im about to bore out my 02 400ex, but im not too sure what size i should go. Im thinkin i either should do a 426 or a 440. I also was thinkin of gettin a 460 stroker, but i heard those have cooling problems. What do you guys think¿

[Kaleigh]

IF you want the biggest and still be reliable I would go with 440..

[Wheelie]

440 stroker, the only way to fly.

[Kaleigh]

is the 440 stroker just as reliable as the regular 440.. never even thought about stroke440.. is that what you have?

[440_Turtle]

its only way to GO:macho

[Kaleigh]

ok i see now.. its a 416 with a stroker.. so that equals 440? right?

where is most of the power.. bottom to mid?

yes im a NOOB with some mods..so dont laugh(to much) :D

[Wheelie]

Your're right, it's a 2mm overbore with a +4mm stroker. Where the power hits depends on the cam and porting.

Even with a stage 3 Hotcams, mine has FAR more low end power than a stocker and pulls hard to the rev limiter.

It's a killer setup.

[400exfan19]

thats kits definately give it alot of power but the reliability and the time the engine will last will go down

[CHEVYZ]

Not true. You make it sound as though a big bore sets your engine up for problems. Although there will definately be reduced life of the engine, it isn't like the same doesn't apply to ANYTHING else you do to the engine to increase performance. Performance comes at a price. Reliability between engines is only a matter of how well the engine was built. :chinese:

[Wheelie]

IMO-My engine is as reliable as the stocker, if not more so. The stock con-rod on a 400ex is a potential weak link--I now have a falicon con-rod. I'm also running a forged piston--much stronger than the cast stocker. I didn't install a rev box--stock rev limiter still in place.

The only thing that might create a problem is the lack of HD head studs. I'm still running the stockers with 11.3:1 compression. 6 months of hard use and no problems yet.

I'm still impressed with how well my quad runs, even 6 months after I finished rebuilding the engine.

[blown331]

I personally think you could make a 440 be just as reliable. In my eyes it's maintenance. Make frequent oil/oil filter air filter changes make sure everything is running cool and you have your jets dialed in and there should be no problem getting a long life out of a performance motor...

you could always upgrade the crank/rod/piston to a higher quality and go even farther with it

[Kaleigh]

so would it be worth it just to put a stroker in my 400 and not bore it out.. I got some addons.

full exhaust,stage1hotcam(yea I know), rev limiter, intake... you know.. just the regular stuff..

[CHEVYZ]

I would do a 440 stroker. Might want to look into changing your cam as well.

[Wheelie]

If you're interested in going with a stroker, check out www.powroll.com. First rate service and the machining work is top notch. Killer outfit to deal with, 5 stars in my book.

Also, if you do a stroker, go with the stg 3 hotcam. The longer duration provided by the cam will help to feed the extra displacement and stroke. Don't worry about low end power, the higher compression/extra disp./and longer stroke will provide plenty.

BTW-- A big factor in the life of an air-cooled engine, as stated before, is changing the oil. I change mine every 15 hours.

[Kaleigh]

great thanks for the info guys.. one more question..

does anything know the formula to find out the displacement with a stroker..

all i know right now is that 416 stroker is 440..

if you dont know the formula just the end number would be good..

does a 465+stroker=500???

sorry guys.. im clueless when it comes to this section..

BTW thanks for all the help..

[Wheelie]

Pi x radius/squared x stroke divided by 1000.

[Kaleigh]

sweet.. thanks.. much appreciated