CarTech®, Inc.
838 Lake Street South
Forest Lake, MN 55025
Phone: 651-277-1200 or 800-551-4754
Fax: 651-277-1203
© 2015 by John Baechtel
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without prior permission from the Publisher. All text, photographs, and artwork are the property of the Author unless otherwise noted or credited.
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Layout by Monica Seiberlich
ISBN 978-1-61325-157-7
Item No. SA308
Library of Congress Cataloging-in-Publication Data Available
Written, edited, and designed in the U.S.A.
10 9 8 7 6 5 4 3 2 1
Title Page:
A similar choke point exists on the exhaust side. It also represents the minimum cross section and typically has a larger radius to encourage smooth exhaust flow, which exits under high pressure.
Back Cover Photos
Top Left:
The throat area immediately above the valveseat is the controlling factor in airflow efficiency. Maximum velocity across the valve should be generated here.
Top Right:
Cylinder heads are the most influential component of an internal combustion engine. They are the gatekeeper that regulates the amount and quality of the air/fuel mixture entering the engine.
Bottom Left:
Naturally aspirated applications typically require much more flow-bench work to extract maximum performance for each application. Experience pays off, but it still may require long hours of trial and error. (Photo Courtesy Smithberg Racing)
Bottom Right:
Modifying port entry angles via specific port matching produces power. The match between the runner exit and the intake port entry should be almost seamless with no sharp edges or area change. Epoxy filling is sometimes required to accomplish the smooth finish. (Photo Courtesy Wilson Manifolds)
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CONTENTS
Dedication
Acknowledgments
Introduction
Chapter 1: Airflow Basics
Chapter 2: Relevant Properties of Air
The MSA and the Air Density Index
Fuel Properties to Consider
Octane Rating
Gasoline Variables
Conclusion
Chapter 3: Engine Airflow Components
Fundamentals of Air Motion
Cross Sections and Path Lengths
Carburetors and Throttle Bodies
Air Velocity and Boundary Layers
Obstructions and Pressure Changes
Wave Tuning
Torque Peak RPM
Chapter 4: Intake Manifold
Intake Manifold Types
Plenum Characteristics