Holley - Vacuum Secondary Square Bore

Before you buy a carburetor, please check that you are buying the correct size. Most carbs’ are sized by how many cubic feet of air per minute, will pass through the venturies. Carburetors will function better if they are mounted parallel to the road, river, sea etc. Be sure your fuel tank is clean, and does not contain any rust or contamination. Fit a new fuel filter in the fuel line, prior to the carburetor. Check before you go out on the road, that your fuel pump is supplying fuel at the right pressure- 5.5-6psi. Check your vacuum advance is connected to the correct port. which is on the side of the primary metering block, NOT under the front bowl! Side hung floats can shut the fuel off when used for Circuit Racing in long corners with high “g” force, centre hung floats will not cause this problem. Vacuum secondary carbs, are best for road cars & can also be used for Circuit Racing, if correctly tuned. Double pumpers are not good on the Street, as you can overfuel your engine & cause very rapid wear & severe engine damage. They are commonly used for Drag Racing. Various books & a DVD are available, to help you set up your Carb correctly. AFR gauges with wide band oxygen sensors are also available, to make tuning a “breeze”. Holley list or I.D. numbers are quoted for each carb, to help in identification. Power valve selection- primary- as a rough guide, check manifold vacuum at idle, and divide by 2. This gives the approximate power valve size. Power valves do not operate until the main system is operational. This is “generally” above 2000rpm.

Street Avenger carbs have many features built in, that would be extra on a regular Holley carb. The secondary chamber is fitted with a quick change lid to enable you to change the spring in a few seconds, the needle & seat is adjustable & clear view sight plugs are fitted to make float level adjustment easier. An adjustable electric choke is fitted to some models & there are two bronze type inlet filters to keep contamination away from the needles & seats. If you need to fine tune the secondary jets, then a secondary metering plate is fitted as standard. Designed specifically for the Street enthuisiast.

Offroad Truck Avenger - Truck Avenger carbs are designed with a unique fuel metering block that eliminates fuel spillover through the boosters at extreme angles to enable climbing a 40 degree hill, and traversing the side of a hill, or nose down on a slope at around 30 degrees. Features: The secondary chamber is fitted with a quick change lid to enable you to change the spring in a few seconds, the needle & seat is adjustable as well as spring loaded & clear view sight plugs are fitted to make float level adjustment easier. An adjustable electric choke is fitted to some models & there is a single inlet with filter fitted, to keep contamination away from the needles & seats. If you need to fine tune the secondary jets, then a secondary metering plate is fitted as standard. This carb is designed specifically for the Off-Road enthuisiast.

The 4150 Street HP Carb’ is ideal for Street/Strip use. It has the same contoured venturi inlets as the Racing HP carbs, for maximum airflow & reduced turbulence, the symmetrical venturi bores offer balanced air flow for increased horsepower. Features: Screw in air-bleeds offer an easy route to more accurate tuning, the down leg boosters are spun in and can’t fall into the engine, Ford kickdown linkage is fitted as standard, two corner idle system with lightweight mixture screws, street/strip calibration for outstanding throttle response, shiny finish for great looks, power valve blow out protection, quickchange spring system for vacuum secondaries. There is also a secondary fuel filter system.