Think a low Ra number and a shiny surface mean you’ve nailed your surface finish? Think again. In this eye-opening presentation from the Engine Performance Expo 2025, surface metrology expert Mark Malburg explains why the numbers can lie and how the true shape of a surface is the real key to sealing, friction, and performance.

As the president of Digital Metrology and Cummins’ former corporate metrologist, Mark translates complex metrology into practical, real-world knowledge for engine builders. Learn why focusing on “waviness” is more critical than “flatness” for gasket sealing and why your most valuable measurement tools might just be your own eyes and a used part.

Key Takeaways You’ll Learn:

🤔 Why surfaces with the SAME Ra number can perform completely differently.

🔬 The critical difference between Roughness and Waviness (and why your skidded profilometer might not see the real problem).

❌ Why “better” doesn’t mean “shiny” when it comes to gasket traction and bearing lubrication.

🕵️‍♂️ How to use affordable tools like Fuji film and worn parts to become a surface detective.

📊 The truth about sample sizes: why it takes 32 traces to trust a number, but only one picture to understand the surface.

⏱️ Timestamps:

00:00 – Introduction to Mark Malburg & Digital Metrology
01:45 – The Human Side of Metrology: Thinking in Shapes, Not Numbers
06:20 – Why Numbers Lie: The Chainsaw vs. Concert Analogy
11:25 – Your Most Important Tools: Using Your Eyes and Your Sense of Touch
13:20 – Skidded vs. Skidless Gauges: What Your Profilometer Isn’t Telling You
15:00 – The Importance of Waviness for Gasket Sealing
17:45 – Using Fuji Film to See What a CMM Can’t
21:15 – Learning from Worn Parts: Let the Engine Tell Its Story
24:30 – Unpopular Opinion: Stop Chasing Shiny Deck Surfaces
29:00 – How Wide is “Waviness”? When Your Gauge Stops Seeing Features
33:45 – Choosing the Right Equipment (Zeiss vs. Mitutoyo)
36:00 – Your Gauge Can’t Repeat? Good. It’s Not Dead.
37:25 – The Power of the Picture: Reading a TraceBoss Graph
39:50 – The Shocking Sample Size Needed for Reliable Numbers
44:15 – Q&A: How Dirt & Cleanliness Affect Your Measurements
48:00 – Q&A: Understanding the Advanced “RMQ” Parameter
53:15 – Final Thoughts