Holley Carburetors. Mike Mavrigian

       Power Valve Removal

       Overflow Whistle Removal

       Mixture Screw Removal from Metering Block

       Choke Assembly Removal

       Vacuum Secondary Diaphragm Removal

       Main Body and Baseplate Separation

       Chapter 6: Cleaning and Inspection

       Solvents

       Cracks and Pinholes

       Baseplate

       Main Body

       Power Valve

       Throttle Plates

       Choke Fast-Idle Cam

       Throttle Shaft and Shaft Bearings

       Idle and Main Well Passages and Emulsion Tubes

       Accelerator Pump Diaphragm

       Needle and Seat Assembly

       Main Jets

       Discharge Nozzles

       Carburetor Renewal Kits

       Chapter 7: Assembly

       Main Body to Throttle Body Baseplate

       Metering Block Assembly

       Accelerator Pump Installation

       Float Installation

       Metering Block Installation

       Fuel Bowl Installation

       Discharge Nozzle Installation

       Choke Installation

       Vacuum Secondary Installation

       Secondary Metering Plate Installation

       Carb-to-Intake Installation

       Chapter 8: Preparation and Tuning

       Torque Requirements

       Linkage Setup

       Engine Pre-Start Requirements

       Emergency Precautions

       Vacuum Leaks

       Throttle Operation

       Fuel Pressure

       Carburetor Plumbing Techniques

       Dyno Testing Your Setup

       Pre-Oiling a Fresh Engine

       Air Cleaners

       Float Height

       Idle Mixture

       Engine Bogs

       Power Valve

       Tuning Vacuum Secondary Operation

       Appendix: Holley Carburetor Models, Part Numbers and Features

       Source Guide

       ACKNOWLEDGMENTS

      Thanks to the following for their assistance in producing this book: Bill Tichenor, Holley; Dave Monyhan, Goodson Tools; Scott Gressman, Gressman Powersports; Brian Carruth, Trick Flow Specialties; Scott Koffel, Koffel’s Place; Tony Lombardi, Ross Racing Engines; Trey, AED; Diro Ahart, CRC; Bob Harris, Lisle Corp.; Robert Holmes, Mac Tools; Thor Schroeder, Moroso; Alan Rebescher, Summit Racing; Willy, Willy’s Carbs; Lista International; and Jody Holtry, Medina Mountain Motors.

       INTRODUCTION

      During the 1950s and 1960s, the Holley 4-barrel carburetor established itself as the clear leader in high-performance operation because it provided precise fuel metering in low-, mid-, and high-RPM operation. Also, it was a modular design that was easy to tune and had a wide range of parts. The Holley 4150-series, or Double Pumper, carburetor distinguished itself during the muscle car era because it had an accelerator arm pump on both float bowls, so if the carburetor were used for aggressive acceleration or wide-open throttle, it would deliver all the needed fuel into the engine when called upon.

      Although the basic architecture of the Holley 4-barrel carburetor has remained largely the same for 60 years, Holley has offered several different series of carburetors, such as the 4150, 4160, Avenger, and Dominator. And of course, many different carburetor models exist within these series. In this book, I review Holley carb styles, models, features, and sizes, so you can accurately identify your particular carburetor and its parts.

      Many classic cars, muscle cars, hot rods, street rods, and competition cars are equipped with Holley carburetors. If you have an OEM Holley carburetor, it is most likely 30 years or older. Over time, gaskets deteriorate and bushings wear and possibly leak, metering blocks and jets are exposed to contaminants and become plugged, jet needles and jets wear from use and no longer meter properly. If you have an aftermarket carburetor, it may be newer but a lot of usage may require a rebuild. Or possibly, you want to substantially change the setup of your carburetor. Whatever your situation, if you have never worked on a carburetor before, rebuilding one can seem daunting.

      The purpose of this book is to take the mystery out of the carburetor rebuild process, and to show you how to do it in straightforward, clear steps. This includes how to disassemble, select parts, install components, and confidently reassemble a carburetor, so your engine and vehicle performs at its best. In the pages of this book, I have documented the entire Holley carburetor rebuild procedure so you disassemble, evaluate, replace worn/defective parts, reassemble, and perform basic calibration. The step-by-step photos illustrate how to perform each step, and the captions explain the tools and techniques required to perform the procedure.

      Before you dive into rebuilding a Holley carburetor, it’s important to understand how it operates. Carburetors are relatively complex devices, and they have a number of circuits, venturis, orifices, and other features. You need to understand how a carburetor and each component functions so you can properly rebuild and tune it. I have included a comprehensive parts guide that provides the available parts for a particular model, so you can select the correct jets, needles, emulsion tubes, and other parts for optimal performance. I also help you select a vacuum or mechanical secondary carburetor for your particular engine and application. Holleys can be set up and calibrated for almost any engine, vehicle, and application.

      If you have built a modified engine or if you’re buying a new carburetor for a particular engine, you need to select the correct CFM (cubic flow per minute) size. Feed too much fuel to the engine and it will sputter and stumble or, in extreme cases, not start. Supply too little fuel and the engine runs out of power on the top end. The instruction and mathematical formulas allow you to select the right carburetor.

      Holley 4-barrel carburetors have a number of jets, needle jets, main jets, and power jets; all of the parts must be tuned as a well-integrated system if you want to get maximum fuel efficiency and performance. This book does not delve into performance modifications. But if you’re looking to setup your Holley Dominator, which is installed on a big-block Chevy, and you plan on drag racing, I suggest you refer to How to Super Tune and Modify Holley Carburetors by David Vizard. In that book, Vizard uses 50-plus years of engine calibration experience and knowledge so you can tune your carburetor for maximum performance for almost any application, high-performance street, drag race, road race, and almost every other form of competition. He also explains how to calibrate the carburetor for almost any engine setup.

      With