Mailbag: The Math Formula for Determining Carburetor Size
Q: I am in the process of rebuilding my 1967 Chevelle. I am looking for the formula to figure out the proper size carburetor. Do you know it? If so, would you please share that? A: We do, and we will. Carburetor CFM = (plannned rpm x cubic inches) / 3,456 For clarity, your carb
Mailbag: Solving Cold-Starting Problems and a Rich-Running Carb on a Chevy 305
You’ve got questions, we’ve got answers. We work with the Summit Racing tech department to help you tackle your auto-related conundrums. In this week’s Mailbag, we’re troubleshooting carb issues in a 305-powered 1985 Chevy van. Q: My friend and I put a rebuilt 305 Chevy motor in my 1985 Chevy van. Since we did this, we’ve been having
Mailbag: Recommending a Carburetor and Gearing Combo to Fix 700R-4 Shifting Problem
You’ve got questions, we’ve got answers. We work with the Summit Racing tech department to help you tackle your auto-related conundrums. In this week’s Mailbag, we’re recommending a carburetor and gearing combo to combat an improperly shifting 700R-4 automatic transmission. Q: I have a 1986 ½-ton Chevrolet pickup with full time four-wheel drive. It has a 350 crate
Mailbag: How to Fix Gas Fouling and Oil Misting on 383-Powered ’55 Chevy
You’ve got questions, we’ve got answers. We work with the Summit Racing tech department to help you tackle your auto-related conundrums. In this week’s Mailbag, we’re troubleshooting problems with gas fouling and oil misting on the passenger side of a 383-powered ’55 Chevy. Q: I have a 1955 Chevy with a 383 motor, a four-speed transmission, and a
Mailbag: Cleaning the Carb on a 1971 Corvette 454 to Fix Engine Stall
Q: I have a Holley 800 cfm double pumper carburetor on the 454 in my 1971 Corvette. The carburetor worked fine when I first installed it. But after the car spent six months in the garage, the engine dies when I go around a corner or when under normal to hard braking. At regular and
Carburetor Basics 101: A Quick Overview of Primary and Secondary Barrels for Street or Race Applications
There is much to consider when choosing a carburetor for your vehicle. Airflow, choke style, and even the physical height of your carburetor will come into play. But what about the barrels? How do they work? And what type of secondaries do you want? Here are the basics you need to know about primary and
Holley Redesigned its Legendary 4150 Carburetor for Racers, New Ultra XP Carb is PERFECT for Tunnel Ram Setup
Spin back the clock about 45 years or so. If you had an engine combination that could handle it, what you really needed was a tunnel ram with a couple of Holley 660 center squirters perched on top. If you burned corners, a cross ram with a couple of 650’s was the ticket. Over time,
A Quick Guide to Carburetor Heights (and Why They’re Important)
When it comes to choosing a carburetor, there are lots of things to consider: airflow, choke style, and secondary type, to name a few. But what about the physical height of the carburetor? The main reason carburetor height is important is hood clearance, especially on certain applications such as Corvettes, and big block Chevelles and Camaros. Most air cleaners and intake manifolds are listed with
Mailbag: How to Cure Spark Plug Fouling During Idle
Q: I own a 1971 Dodge Demon with a 400. The 10.5:1 compression engine has a forged crank and “LY” rods, and has a balanced bottom end. The heads are 906 castings port matched to a Weiand Team G intake and 2.5-inch headers. The heads have also had port work done. The cam is a Mopar Performance
Ask Away! with Jeff Smith: Converting a Draw-Through Carburetor to Blow-Through
I have a 850 Mighty Demon carb marked BC 56. The carb is designed for use with a Roots or draw-thru supercharger. I want to use it for blow-through using a hat. From pictures I’ve seen, it looks just like a blow through carb except for the milled tracks going to the throttle shafts. What must
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