Has any one done the 465 big bore kit to their 400EX? I want to know how it stacks up against the 440 kit, a banshee, raptor etc. How does it do on sand hill drags also?

 

Well I guess I'll have the only one next season huh? Cool I'll be smokin all other EX owners.

 

Hey you might call GT Thunder and ask if they do it. They do some pretty crazy stuff with 400exes. Go to http://www.geocities.com/gtthunder.g...vices_set.html

For a phone number and other info

Sorry i couldn't help you more

 

I personally wouldn't go any bigger than the 440. Really, you can get some serious power out of a 440, and I think much more than that and you'll start grenading engine parts like the crank or rod or rod bearings etc. etc.. Plus the 465 (is it a stroker?) might not rev as good as the 440, and it's possible you would actually be making more low-end and midrange torque, at the expense of less peak horsepower.

Then again, I could be totally wrong, but that's my oppinion on it. Just get a 12.5:1 440 with a big cam, full porting, full exhaust, FCR carb, should be making a good 45-50hp on VP race gas.

 

Sparks Racing's 465 is just a big bore..not a stroker. They use a sleeve that is the same thickness all the way from top to bottom. SO they can bore it larger without risking making the bottom of the sleeve to thin like you would by going really big on a tapered IMS sleeve. Other than that Curtis Sparks said when I asked him about it that for racing the piston was a little heavier than he would like to see and recommended a 416 or 440.

Adam Smith

99 400EX

 

Thanks for the advice and response. An other question though. Which would be better for long steep sand hill raceing in your oppinion, the 440 or a 465?

 

If you want to climb big steep sand hills then I would suggest a 416 or a 426. You need more rev with those big hills and the 440 is just torque. My 426 revs awesome, and can beat all piped Banshees up the hills. I can shift while climbing the steepest part of the hill, and I do not need any run at them.

 

On GT Thunder's website under the news section they have a dyno for a 473cc 400EX from FDO racing that dynos at 51.9HP. That seems pretty interesting if you are looking for info on a big bore. They have their phone number on the site too. www.geocities.com/~gtthunder/news_set.html
Also, they have several dynos on other motor configs like full blown 440s and 425s. So you can kinda get some info that could be useful to you, not to say that a dyno is the ultimate indicator in the effectiveness of a certain motor configuration.

Adam Smith

99 400EX