How do you figure out what cfm carb I need?
The formula for calculating how much CFM (cubic feet per minute) your engine requires is: CFM = Cubic Inches x RPM x Volumetric Efficiency ÷ 3456.
- Example: Using a 355 CID engine x 5,500 max rpm = 1,952,500.
- Take 1,952,500 x .85 = 1,659,625.
- Then 1,659,625 ÷ 3456 = 480 CFM.
What cfm carb do I need for a 350?
A 600-cfm carburetor may perform quite well on a stock 350 Chevy. However, the minute you start weaving in power adders like a hotter cam, a dual-plane performance intake manifold, and aluminum heads you’re going to need 700-750 cfm.
What happens if carb is too small?
The carb is actually too small to let the engine realize its maximum power potential. Thats because the greater the pressure drop (the higher the vacuum reading) across or through the carburetor, the lower the air density is inside the intake manifold and combustion chamber.
Which is better single or dual plane intake?
Choose a dual-plane intake for better idle quality, off-idle throttle tip-in response, and better air/fuel charge distribution to the cylinders at low rpm. Choose a dual-plane intake if you want longer runners to move the rpm band down.
Which carburetor spacer is best?
The 4-hole plenum spacer is most effective when it’s made from phenolic resin or a polymer. And the good news is that phenolic resin spacers can be stacked, the same way as wood or aluminum spacers. So if insulation and durability are both important to you, this may be the spacer for you.
Can a carburetor be too big for an engine?
How do I know if my carburetor is too small?
If the carburetor is too small, it restricts airflow into the engine. The cylinder can’t fill up all the way. This starves the engine and results in slow acceleration and a lack of top-end power. A larger displacement engine running at higher rpm will require more air and fuel.
How much horsepower does a 355 put out?
There’s a sweet spot in the horsepower-per-dollar equation, and this 355 has its coordinates firmly locked onto that juicy territory. Scoff, if you will, at its mediocre 467hp output, but printing a big number on the dyno sheet with utter disregard for fiscal responsibility isn’t what this motor’s about.
Do carb spacers increase cfm?
If all the aforementioned engines had peak-power rpm at say, 1,000-rpm higher, they may have needed to have as much as 1 inch of extra spacer to access that power. Tip Four-Spacers Increase Carb CFMIf designed as one of its primary functions, a carb spacer can be used to increase the cfm delivered by the carb.
How to contact Holley carburetor technical information?
Holley Carburetor Numerical Listings Technical Information Technical Information Tech Service: (502) 781-9741
What is the bolt pattern on a 0 8007 carburetor?
Carburetor Numerical Listing for Part #0-8007 This model of carburetor has the square bore flange bolt pattern. It can replace Holley, Edelbrock, Carter AFB, and Autolite style carburetors with 5 3/16″ x 5 5/8″ bolt pattern. If you have a spreadbore style intake manifold, you will need an adapter to install this carburetor.
What is Holley 0-8007 calibration?
Holley’s 0-8007 is calibrated and intended for small V8s or 6 cylinder engines as well as 2×4 street tunnel ram style set ups. Plus, it is Gold Dichromate coated for durability and classic Holley looks.
How do you read a carburetor list number?
Depending on the age of your carburetor, the list number can begin with distinct markings. Vintage (pre mid-60s) is typically denoted with “R”, while later models can be stamped with “L”, “List”, or the modern convention “0-“.