I have a stock 400ex. My 400 has some mods a WhiteBrothers R4 exhaust, WhiteBrothers cam, WhiteBrothers Revbox, K&N filter and MotoForce airbox lid.
What I wanted too know is I'am gonna have the cam installed soon and I was gonna put a JE high compression piston R/D valve springs and different valves any advice on valves. Will all the mods I already have and the ones I want too install be as fast or faster than a 416 kit. Will it also be more reliable. I priced the JE 416 kit and it is only 150.00 bucks more then having the cam installed so I was just wondering what you guys thought. I also heard a well built 416 is faster than a 440.

 

i'm not sure about the speed. but i think that a properly set up 416 kit can run better all around, than a 440 kit. apprantly the 440 has problems with revving, where the 416 revs quickly, and doesn't stop. depending on the fuel that u run, and gearing, i wouldn't be suprised if u keep up with a 416 kit. good luck with the mods.

 

I have the 440 and have never had any problems with reving

 

yeah..same here..my 440 revs out very fast too..

 

They say a 416 is faster than a bad 440. By bad i mean wiseco where the compression is messed up or it isn't cammed. If you want a 416 that sceams and you want to run pump gas get the je 10.8:1 and hotcams stage 2. Call C&D Racing they'll set u up.

 

If you want it to be as fast as possible go with a 13:1 piston and get your head ported too with some oversized valves. You'll have to run race gas but it will be pretty fast. You would probly want to look into a heavy duty rod if you go that hi on compression. I would look into a carb if i were you too.

 

i have the wiseco 440 kit with a stage 2 ca and i have had no problems, revs fast too.

 

Make sure you get a FCR39MM carb. A must have. Good gains on stock motor, HUGE gains with a built motor.

 

Hey thanks guys do you think my mods and the internals on my stock bore will keep up with a 416 and last longer.

 

You want a fast 400EX, talk to "AZsand" in the Bombardier forum. I believe he has a 465ex on methanol and it beat's Stage 3 DS's and similarly modded modded Raptors....