I was thinking about changing out my intake manifold a carburetor but didnt know if i should go up to a four barrel. My neighbor said to go up but ive been told it doesn't make too much of a difference except make gas mileage suck. if that's the case is there a performance 2 barrel? im running a stock v8 engine with a stock carb and manifold. I just want come more power.
You'll probably get a tad bit of better gas mileage with a smaller 4 barrel carb as long as you keep your foot out of it and don't get into the secondaries much. I would have a hard time with that because I enjoy acceleration too much. I'm actually looking to get a slightly larger 2 barrel carb, either a Holley 2300 (350cfm) or another Autolite 2100 (1.21 or 1.23 venturi, approx 350cfm) which should give a little better performance without killing my mileage on my daily driver....plus it's way easier of a swap and only around $150 for rebuilt units on Ebay, cheaper if you want to rebuild yourself. Maybe down the road I'll swap the intake/carb for a 4 barrel setup, but right now it's not in my budget.
You will improve performance by improving airflow in and out of an engine. That said a carb swap is only a piece to a long list of carefully selected items to accomplish your goals. Personally, if the car is running good now, I would start with improving the exhaust system.
If you're worried about gas mileage, then buy a Toyota. As for a carb upgrade, either Holley 350 or 500 are an improvement over an Autolite 2 bbl. The 500 will tend to use more fuel due to the 50 cc accellerator pump though. But it's like bolting on 20 hp with minimal effort.
lol i already drive a toyota corolla....way ahead of you on the gas milage thing lmao. but you say 500 over 350? would I need a new manifold for the 350 0r 500 holly. im running straight pipes right now and I recently fabricated a functional hood scoop.
So if I put on a 500cfm Holley 2bbl and switched the 50cc accelerator pump with the 30cc pump, would that give me close to the same gas mileage as my Autolite 2100? I can't afford a Toyota!
Your neighbor doesn't know what he's talking about. The simple upgrade to a 4-barrel can give you an instant extra 25 horsepower on an otherwise stock engine. The gas mileage won't be any different under normal cruising conditions, but naturally, when you put your "foot to the floor", it's gonna suck more fuel (and make more power). Go with the 4-barrel if you want more performance. if you don't feel the need or desire for more power, leave the 2-barrel on it. I would not mess with a 500cfm 2-barrel. Either go with a 500cfm (or 600) Edelbrock, a 570cfm Holley, or a 600cfm Holley.
No manifold swap needed they're direct bolt ons with a minor fuel line reroute. The 350 is closer to a stock carb, the 500 is simply half of a 750 DP Holley 4 bbl. It's probably the most reliable carb Holley ever made. I've used the 500 on everything from a stock 302 to a 400M. It works on everything and is a vast improvement over an Autolite 2 bbl.
I dont know, I've never tried the pump swap on one. It's a simple operation though, try it and let us know how it turns out.
