Join legendary race engine developer Darin Morgan of BES Racing for Part 2 of his masterclass on Advanced Induction System Tuning (part 1 is here).

In this deep dive, Darin pulls back the curtain on the science and art of modern cylinder head port design, explaining the critical shift to highly efficient “High Mach Index” ports.

Drawing on decades of experience and surprising lessons from WWII-era aircraft engineers, Darin reveals how to maximize airflow by understanding the relationship between port shape, piston speed, and mean gas velocity. He breaks down complex topics into understandable principles, showing you why the “old ways” of porting are obsolete and what it really takes to make power in a modern engine.

In this video, you will learn:
🔹 The secrets behind “High Mach Index” ports and why they’re essential for power.
🔹 The critical 50-70% rule for the short side turn that unlocks high RPM.
🔹 Why piston speed, not just RPM, is the key to mean gas velocity.
🔹 How to design a port for a specific purpose (Street Torque vs. Race Power).
🔹 Darin’s controversial take on port dimpling (and why he calls it a “gimmick”).
🔹 The power of a wet flow bench to see what’s really happening with fuel.

📌 Chapters:
00:00 – Introduction: The Impact of Modern Valvetrains
00:46 – What is a “High Mach Index” Port?
01:14 – The Critical Role of the Short Side Turn
02:50 – Learning from F1: Bowl Volumes are Shrinking
04:00 – High vs. Low Mach Index Ports Explained
07:22 – Visualizing Fuel Flow with Wet Flow & Strobe Lights
09:05 – Learning from History: WWII Aircraft Engineers
11:51 – Mean Gas Velocity: The Fundamental Principle
14:00 – Piston Speed in Modern Engines
17:05 – The Goal: Exchange Velocity for Pressure
18:18 – Bore-to-Stroke Ratio and Valve Area
20:10 – Who Uses High Mach Index Ports?
22:50 – The LS7 Head: A Purpose-Built “Bad” Port
26:00 – Offset Throats and Modern Port Design
30:11 – Case Study: Designing a High-RPM Engine Port
32:55 – Port Taper and Volume Ratio
34:55 – Host Question: Port Dimpling
38:15 – Host Question: Using Vortices and Turbulence
43:10 – Seat Cutting, Sharp Angles, and Manufacturing
51:00 – Porting Boosted Engines
53:20 – Q&A: Runner Finishes (Burr vs. Polished)
56:15 – Q&A: Dyno Repeatability vs. Accuracy
1:01:25 – Where to Learn More & The Future of the Industry

An amazing deep dive into the cutting edge of modern race engine development. If you’re serious about horsepower, airflow, and performance, this session is one you’ll watch more than once.