building a 440 motor any reliability issues and gncc prep

[400exrich]

I plan on racing in gncc with my 400 I have full pro armor skid plates ,razr 2 fronts ,razr rears ,ac nerf bars ,full yoshimura exhuast ,acerb hand quards and a renthal chain and sproket kit 15 tooth front and a 36 rear tooth I plan on getting xc 1+ a arms and and 1+ rear axle, fox shocks ($700) ones and send the rear shock out to get rebuilt, steering stabalizer, kill switch, front bumper, a aluminum airbox and a upgraded oil tank and oil cooler my major concern is building the motor I think I'm gunna put a 440 and stroker kit on it and a bigger in take vavle with a stage 2 cam and port and polsih the head I was wondering if the quad will still be reliable I know the vavles will have to be adjusted more please help and I plan to send the frame out to fix the 400ex weak spots.:devil::devil:

[JOHNDOE83]

I plan on racing in gncc with my 400 I have full pro armor skid plates ,razr 2 fronts ,razr rears ,ac nerf bars ,full yoshimura exhuast ,acerb hand quards and a renthal chain and sproket kit 15 tooth front and a 36 rear tooth I plan on getting xc 1+ a arms and and 1+ rear axle, fox shocks ($700) ones and send the rear shock out to get rebuilt, steering stabalizer, kill switch, front bumper, a aluminum airbox and a upgraded oil tank and oil cooler my major concern is building the motor I think I'm gunna put a 440 and stroker kit on it and a bigger in take vavle with a stage 2 cam and port and polsih the head I was wondering if the quad will still be reliable I know the vavles will have to be adjusted more please help and I plan to send the frame out to fix the 400ex weak spots.:devil::devil:

I owned a 440 with valves, cam, big carb, cdi... all the good stuff without the stroker.

I owned that motor for well over 7 years with NO issues and never adjusted the valves except when i put the cam in.

I never got heavy duty studs but I suggest getting them if your in GNCC and gonna stroke it out.

The trick is to jett it very large, my 440 used a 220 main jet another guy here uses a 230 main jet.

Jetting is the key for a 440 or any built ex motor to maintain reliability and get the most HP and performance out of the motor.

Reliability will be shot if you run it to lean, it will also rev slow if its to lean.

But like I said I went 7 years without studs, another member here built a fresh 440 and blew studs and gaskets twice already.

[400exrich]

I owned a 440 with valves, cam, big carb, cdi... all the good stuff without the stroker.

I owned that motor for well over 7 years with NO issues and never adjusted the valves except when i put the cam in.

I never got heavy duty studs but I suggest getting them if your in GNCC and gonna stroke it out.

The trick is to jett it very large, my 440 used a 220 main jet another guy here uses a 230 main jet.

Jetting is the key for a 440 or any built ex motor to maintain reliability and get the most HP and performance out of the motor.

Reliability will be shot if you run it to lean, it will also rev slow if its to lean.

But like I said I went 7 years without studs, another member here built a fresh 440 and blew studs and gaskets twice already.

Thanks I will post some pics when I do the build

[jcs003]

i had one built years ago by mickey dunlap and it ran forever with no issues. trick is to using all good bearing, gaskets and etc., and being up on maintenance. using quality fuel and oils, keeping the filter clean and not overheating it; along with keep the valves in spec you should have zero issues.

john

[400exrich]

I plan on using pump 93 playing around and when I'm gunna race I'm gunna use vp race fuel and thanks can't wait to build it

[Longdong]

Do you plan on running every round?

[400exrich]

Do you plan on running every round? I plan on it I want to race in the pros so I want to get noticed so I most likely will

[Longdong]

How much do you think it will cost you to run a full season (food, fees, gas, ect)?

[ben300]

I plan on it I want to race in the pros so I want to get noticed so I most likely will


:huh

you ever race a gncc before?

[400exrich]

:huh

you ever race a gncc before?
I have raced thru alit of trails just like gncc. Jumping logs hitting jumps mud holes so I'm trying to race but no I haven't raced at a real race

[DragonGunner]

Good luck, a guy on this forum started his first race with the GNCC last yr. and has gottin better each race, he's really hooked.

[ben300]

I have raced thru alit of trails just like gncc. Jumping logs hitting jumps mud holes so I'm trying to race but no I haven't raced at a real race

well if i was you...and this is just me...and i race the GNCC's, and other local races..


id run a local race first. dont know where your from, so i cant tell ya what, but id run a local race or two to get the feel for it. the GNCC's are a whole other animal than your locals. the competition is way better, way faster, bigger, and the tracks are usually longer and more technical/aggressive.



now as for your quad. you can be competitive in the AM race on a 400, theres guys that do it (see marshal goings or garon davis for example), but your gonna get run all over in the PM race.

reliability and longevity when racing 2, sometimes 2+ hours is the key, not pure, ignorant horse power.

if i was you, id focus most of your money on your suspension set up, because thats gonna do more for you when racing XC than any motor mod. properly set up suspension is gonna make you faster because you are gonna be able to handle the track and its different conditions better, and you are going ot get less fatigued in the long run.

then id build a motor with the following:

1) stock bore 10.8:1 or 11:1 high comp piston from either wiseco or JE
2) stage 2 hot cam
3) 2002-2005 crf450 cam chain
4) new valves and valve train

these motor mods above will give you a solid boost in power and performance, and will maintain good reliability.

if you have extra money to spend

5) GT thunder head studs
6) larger oil coil and spal fan
7) 04-05 450r carb
8) mild port and and polish

[Drifterboy3]

I'd say a 416/426 for a little more top end still plenty reliable. I ran an ixcr in April 11:1 piston stock bore was good power until the straights. That the second lap I got hit and broke a femur...

[Chukkinsod]

Almost a must to get GT Studs due to the bore of a 89mm being so close to the stud....heat will pull the stud (only matter of time) also while you have it apart put in a CRF 450 timing chain and MAKE SURE you put a NEW timing chain adjuster on. I have seen too many people bend valves because the adjuster wears out and jumps a tooth......just maintenance (I replace every year cheap insurance to save from costly head repairs) even a bigger B if you have +1 and bend them in the head.

[MtnEX]

Humm... I see quite a bit of mixed suggestions.

I am not sure where I am going with my own motor. But I can tell you the $700 floats are not going to get you to the front. You would be better off spending the motor money on better suspension. It is everything in racing. Even XC / GNCC.

[toby400ex]

You should run Pro Class for your very first race....... ever. That is an awesome idea. :)