need carb size for a 418

[50ceptor]

i bought a 750 speed demon for my 351w and now i have decided to go with a 418 stroker. will i need to go a size or 2 bigger with my carb it will have a 205 or 225 head on it.

 

[86bluecobra]

A 750 seems to bwe the carb of choice in the car mags when they dyno the stroked 351w. Perhaps a 850 but if you have the 750 i would say use it.

 

[Realmongo]

I second giving the 750 a shot on it.

 

[jjd975]

You can try the 750 but a good rule of thumb (if I remeber it right) is 2 cfm/cube.

Guess it comes down to what you want out of the car.

 

[jgfiveoh]

cfm= [(displacement 418) x (how high the engine will be revving 6000?)] / 3456


this will get u close but it depends on what u r doing with it. if you get to high of a cfm carb u may end up hurting power.

 

[50ceptor]

thanks guys, it will be a strip with an occasional street cruise. the 750 is new so icould return it but if it will work that would be great.

 

[86bluecobra]

I think it should work fine. If you were going to rev the engine above 6500 i think you would need more carb.

 

[83Mustang427TT]

750 cfm is what I ran on my last combo 351w stroked to 427 ci. with a single turbo and it was fine for street and some track use 850 might be better like blue cobra said if you rev up in the 6500 range but if your using a 2 bolt main style windsor block as a base without a stud girdle I dont suggest that