Practical Engine Airflow
Performance Theory and Applications
The all new Practical Engine Airflow book by John Baechtel seeks to demystify this complex subject and present the basics of engine airflow in easy to understand terms for the average hot rodder and engine builder. You don't need to know a lot of mathematics to understand and apply the basic concepts to improve your personal engine projects. The dynamics of airflow in a running engine are quite well understood at this point in time and this new book offers insight and clear explanations of what happens to the air on its journey through an engine and why increasing airflow is the key path to power.
The book describes the airflow path from atmospheric pressure entering the engine to atmospheric pressure after exiting the engine and all the various changes that occur in between. The secrets to max power are in the processing of air through the engine and efforts to increase the capacity and conditioning of the air/fuel mixture as it moves through the engine.
The physics of airflow are quite complicated but this book walks the reader through the process starting with air entering the engine at the air cleaner and following the various velocity, pressure and temperature changes that occur through the carburetor, the plenum, runners and ports, combustion chambers and out through the exhaust flow paths. It relates all of these components to links in a chain that represent an expansion of the four cycle concept with three additional cycles that are actually the key to improving torque and power. For example if you always thought that the compression stroke is the same length as the crank stroke, you need this book. It describes in detail the seven cycles of operation and how they are all closely linked with each cycle setting the stage for the next.
The book leads off with an explanation of Patrick Hale's seven cycles and a look at fundamental properties of air and fuel. Hale of course is the original engineer behind the widely regarded Engine Pro simulation software. Each subsequent chapter describes in detail what happens and why when air moves through a particular flow component such as a carburetor or a cylinder head port. The discussion of valve throat diameter to valve diameter is particularly eye opening and you'll be glad you read it. The information comes direct from some of the top experts in the field.
Flow testing and analysis are also covered with descriptions of various flow tools and techniques. Finally practical applications are presented to illustrate how some builders and designers approach particular flow problems in constructing intake manifolds. There's very little math, but a lot of detailed explanations and solid well proven information.
The book is directed at entry level and advanced engine builders and serves as a road map through the engine with mile markers, road signs and point of interest along the way. You will gain a fundamental understanding of how air is processed through an engine and how those processes convert air and fuel into tire wrenching power.
- Series: Pro Series
- Paperback: 176 pages
- Publisher: Car Tech (December 15, 2015)
- ISBN-10: 1613251572
- ISBN-13: 978-1613251577
39966 Grand Ave.
North Branch, MN 55056
Noted Reviews from buyers:
Practical Engine Airflow by John Baechtel, is a Pro Series S A design book that is extremely well-written. It is an in-depth book that covers performance theory and applications, how to interpret data once you have it, flow bench testing, and optimizing intake and heads. I like the way this book is laid out because if follows in a rational order and it has lots of photos and drawings and is very easy to understand which is good because this is a very difficult subject to grasp. We start with some really great explanations of the airflow basics and then we get into the prevalent properties of air which is really pretty technical but the way it’s laid out it’s not that difficult to understand. The parts that I thought were especially interesting were the engine airflow components, like carburetors, throttle bodies, and how to do wave tuning. There is also a section covering torque peak RPM. There’s an entire chapter devoted just to the intake manifold’s plan and characteristics and what you can do to modify these to make them work better. Then we get into cylinder heads and that where this book really shines. There is really a lot to this, looking to see where the power comes from, what’s the best racing combination, what are the flow factors, what about valves and valve sizes and how to evaluate your cylinder head potential.
Then we move on to combustion chambers and cylinder filling pressure recovery and combustion power and efficiency. And from there we move down to the bottom end, which is the exhaust system. I especially like the photos and the detail in the charts as you go along, which helps to explain the different types of exhaust ports. The book also talks about flow path disruptions, exhaust flow tuning and what you can do to make this all flow more efficiently. Next up is the flow bench testing and this is where it really becomes interesting. This is for the rubber meets the road, so to speak. We got everything put together, and now we test it and it will tell us right up front what’s working what’s not and why. there are lot across section photos and drawings that really are necessary to do to fully understand what he’s trying to explain and then we sum the whole thing up with practical applications beginning with the software program and then a tremendous section on engine Masters challenge hemi intake and another example using Cal Automotive Customs 409 hybrid intake manifold. I would say he thoroughly covered the subject. I found it very interesting. Again, excellent photos and graphics, and lots of good concise material. I highly recommend this book, especially if you’re looking to make your car go faster. -DB
I can not say enough wonderful things about this book. From the easy to view size and generous number of well defined, precise photographs, to the clear instructions which did not make me feel like they were "dumbed down" for me. Straightforward and complete.
I spent a good number of hours during high school hanging around garages.
I have spent weekends with friends up close and personal at the racetrack.
I even took a "nontraditional careers" weekend preview course for female auto mechanics at a local trade college. I believe that I learned more, understood more, in this book than those previous experiences and explanations. I plan to buy other books in this series and read them more than once.
I also had better educated (than me) mechanics look at this book and all were impressed.They said to bring other books by this author to the shop.
If you have a child interested in engines or autosports or someone of any age who can appreciate understanding more about the language and fundamental operations of engine efficiency, you need a copy of this book and I am betting others in the series. I am looking forward to being able to better take part in conversations with my increased understanding. -LD