Carb Question

[socor7]

I have a carter AFB off of an old stroker motor, and have put it on a new gm 350. Since the old motor had a 383 crank and I am sure was bored over (the reason my old motor broke cracked cylander wall). Since the 383 flowed more air would the carb have been jetted differently and is there any way to tell if it has been re jetted.
I am wondering because it doen't smell like it is burning right at idle I have tuned the carb so it idles well around 750 rpm. but am wondering if it was over jetted. Any help would be greatly appreciated.



Thanks
Drew.

 

[socor7]

I guess very few know about Carter

in general then would I need to re jet a carb going from a 383+ cubic inch motor to a 350 cubic inch motor, because to me the fuel curves would be different.



Thanks


Drew

 

[motorman]

I have a carter AFB off of an old stroker motor, and have put it on a new gm 350. Since the old motor had a 383 crank and I am sure was bored over (the reason my old motor broke cracked cylander wall). Since the 383 flowed more air would the carb have been jetted differently and is there any way to tell if it has been re jetted.
I am wondering because it doen't smell like it is burning right at idle I have tuned the carb so it idles well around 750 rpm. but am wondering if it was over jetted. Any help would be greatly appreciated.



Thanks
Drew.

the carb limits the amount of air flow no matter what size the engine and if the carb is a smaller AFB,625 CFM, you should not need to rejet.

 

[wishuwerehere82]

Yep, the fuel/air mixture should remain constant no matter how much air it is sucking. The idle mixture can be adjusted to agree with your new lower flow rate with the 350. But it should run just as well at higher RPM's.

So Drew, how do you rate the crate motor compared to the old one?

 

[socor7]

Well since I did not find out unitl after the old motor that is was an overbored 383 (about 400 ci). They are actually pretty comparable. but I can feel a little difference off the line the 383 pulled a little harder, but at the top end the 350's higher hp really helps. I went with the vortec heads because of a story in a mag, they did a cam swap in it and had 400 hp and 425 lb torq.