426 or 440

[flat_track400ex]

ok guys i'm getting ready to order a new top end and was wondering to go w/ the 426 or the 440 i am seeting it up for flat track racing ?
thanks

[98red]

for flat track racing i would go for a 440 but if your looking for more torque try the 416...its a little quicker.

[allmixedup047]

if it was me i would go with the 416, i have heard nothing but great things about that bore. i have heard from some people that run a portable dyno down at little sahara that they had a 440 and a 416 and the 416 would walk that 440. also there was a guy that had a 465ex on alcohol and he said he had that quad at a 440 and a 416 bofor that and he said the 416 was a better running quad. my uncle has a 416 that he dyno'd at 40hp and im not for shure what his torque curve was, but his name is bad habit on the site, you might try to talk to him about it. hope that info helps you out at all.:D

[TM426]

Originally posted by 98red
for flat track racing i would go for a 440 but if your looking for more torque try the 416...its a little quicker.

The smaller the bore it will rev faster but a 440 will give you MORE torque. I would go 426. It has more displacement then a 416 but will rev faster then a 440. A 426 will also be more relighable then a 440 less strss on head gasket, and rod.just my .02:macho

[TC426EX]

Go 426 its the ideal bore size for the EX...

[redroost85]

This subjet has been discussed extensively on here, so a search may do you some more good on getting a better idea of what you want.

On a personal note, at the flattracks around here, the 440's rule the roost...the other's can hang, but just can't beat the straightaway speeds...just my experiences though.:)

[TC426EX]

Yes, I forgot hes gonna be running flat track... For flat track you may want to go with the 440 since you dont have as many speed changes as in MX...

[allmixedup047]

shifting would happen more on the 416 on flattrack than it would with the 440 but you could do some sprocket testing if you went with the 416. all i know is the guys running that dyno we tested on said that bad habits 416 was the best running 400 they have ever seen. but he has couple bucks put in that motor. 40.4hp is pretty darn good for a 416. but he has well over 10grand in that quad. 426 would prolly be your best bet. just for reliability. and its kinda a happy medium.