Just wondering. I'm not really serious about doing it. I just wondered what advantadges/disadvantadges there would be. It seems as though a 350 with a 500 cfm Holley 2bbl sitting on top of the edelbrock sportsman vic jr. intake (or maybe a weiand single plane w/ adapter) would be a great streetable, easy to tune torque monster with the right cam. Am I wrong? Has anyone messed with 2bbl's on a V-8?

 

One problem is jetting it right. You cant get a blend of gas mileage and power like you can with a 4bbl

 

I think I see your point. Do you think the jets on a 2bbl would have to be larger than they normally would on, say, a 4160? I could see where efficiency might be compromised, especially as compared to vacuum secondary carb.

 

1st, 2bbl carbs are rated at a higher delta pressure than 4bbl's, so a 500 cfm 2bbl would not flow as much as a 500 cfm 4bbl.

2nd, because all of the air is flowing through two relatively large venturi, air velocity will be down, which will have a negative effect on fuel economy and throttle response. They were used on "economy" engines because it was more economical for the factory to put them on base V8 engines, not because they were more economical to operate.

But, there were a bunch of 350 and 396 Camaros and Novas delivered with 2bbl carbs in the mid- to late-60's. Class guys got a pretty good break using that carb, so had a lot of success running them on the strip. But, again, not the best street carb.

 

I once had a '70 firebird with a 350 2bbl and it ran like a scalded ape. would burn the tires off just by hitting the gas didn't even need to hold the brakes. I don't know about the mileage though, i was 18 and only cared about going as fast as I could get away with.