rochester carb

[fastgranpaw]

has anyone had any luck running the rochester 2 barrel carb? is there a carb. shop in texas that "works" on them.

thanks.

[JamesHigdon]

Yes, you have a PM

[ps 72]

www.jbcarburetors.com

 

talk to Joe Ballard

[DirtRacer9s]

If you had a choice between a 4412 and a Rochester 2g which would y'all choose. I think it's called a 2g.

[jwmbishop]

thats easy, depends on which 2g and how much cam and what your peak HP rpm is.

 

1 1/4" flange, 1 7/16" throttle bore, 1 3/32" venturi - 278 cfm

1 1/2" flange, 1 11/16" throttle bore, 1 3/16" venturi - 352 cfm

1 1/2" flange, 1 11/16" throttle bore, 1 1/4" venturi - 381 cfm

1 1/2" flange, 1 11/16" throttle bore, 1 5/16" venturi - 423 cfm

1 1/2" flange, 1 11/16" throttle bore, 1 3/8" venturi - 435 cfm

Armed with this info you can pick the one that gives peak flow velocity at your given rpm. One of the things we found was sometimes a 4412 over does it - more volume (higher cfm) at the same vacc drop lowers velocity and as velocity at the venturi drops so does fuel atomization - so there is a benefit in getting right on the correct CFM for your application - even if the lower cfm limits total rpm (much like the sp2p street manifold in the 70's - all done at 4800 but MAN what a diff from 3500 to 4500!). My mother had a 72 olds omega with a 350 and the big 2g - it would keep up with the 72 camaro 350 4 barrel - til about 95 mph.

 

the 2g is very popular with off roaders as it works at very high inclination angles - both fore and aft and left to right. This is the only reason I would consider one - slosh in the turn is minimal... a 4412 will out airflow it and be easier to fine tune - and slosh can be controlled with the circle track baffle (or accomodated with 1 size bigger left jet) especially if you tow to different tracks (altitude) or run in widely different air temp\humidity. And the likelyhood of fellow racers having what you need when you need it is increased. I would run the 4412 in this case.