How Engines Work - (See Through Engine in Slow Motion) - Smarter Every Day 166

TL;DR

A four-stroke engine works by repeatedly drawing in a fuel-air mixture, compressing it, igniting it to push the piston down, and expelling the exhaust gases. In Smarter Every Day 166, Destin uses high-speed footage of a Briggs & Stratton engine with an acrylic head to reveal this cycle inside a working cylinder. Read on to understand each stroke, spark timing, and why the builders initially used propane.

Transcript

Hey, it's me Destin: welcome back to Smarter Every Day. You've probably cranked a car engine thousands of times in your life, right? You're familiar with that roar as the engine comes to life? Have you ever thought about what's going on inside the engine? Think about it. You've got thousands of explosions happening every minute and they all come to... Read More

Key Insights

• 🦾 Everett and Mike expertly convert engines into various mechanical creations, showcasing their mechanical prowess.
• 🚒 The transparent engine allows viewers to witness the four strokes of the engine, providing a valuable educational experience.
• 🖐️ Timing plays a crucial role in engine performance and efficiency.
• 🚒 Propane can be used as an alternative fuel for engines, providing benefits such as cleanliness and longevity.
• 🥰 The collaboration between different generations, as seen with Everett, Mike, and Bill, highlights the shared love for engines.
• 💗 Subscribing to their YouTube channels can support these small channels and help them grow.
• 💅 The book recommendation, "The Walking Drum" by Louis L'Amour, explores the journey of a young man in 12th century Europe and offers valuable wisdom.

Questions & Answers

Q: How does a four-stroke engine work?

A four-stroke engine repeats four stages: intake, compression, power, and exhaust. The engine draws in a fuel-air mixture, compresses it, ignites it to drive the piston down, and then clears the burned gases from the cylinder.

Q: What happens during the intake stroke?

A valve opens as the piston moves, drawing a fuel-air mixture into the cylinder. When the piston gets near the bottom of the cylinder, the intake valve closes.

Q: What happens during the compression stroke?

After the intake valve closes, the piston compresses the gas inside the cylinder. This prepares the fuel-air mixture for ignition during the following power stroke.

Q: What happens during the power stroke?

The fuel-air mixture ignites, producing an explosion that raises the pressure inside the cylinder. That pressure applies force to the face of the piston and pushes it down.

Q: What happens during the exhaust stroke?

After the gases have burned, the exhaust valve opens. The fourth stroke clears the exhaust gases from the cylinder before the intake valve opens and the cycle begins again.

Q: Why does spark timing matter in an engine?

The spark should occur just before the piston reaches top dead center so pressure builds as the piston is ready to move downward. Advancing or retarding an engine's timing refers to changing this spark timing.

Q: How did Everett and Mike make the Briggs & Stratton engine transparent?

They removed the normal metal head and replaced it with an acrylic head, making the inside of the cylinder visible. They also moved the spark plug and fired it using a buzz coil from the 1920s so the camera could look into the engine.

Q: Why did the transparent engine initially run on propane?

Everett and Mike used propane instead of gasoline because it is cleaner and makes the engine last longer. They later converted the engine to gasoline in a matter of seconds so Destin could record a brighter flame.

Summary & Key Takeaways

• Destin visits Everett and Mike, who specialize in converting Briggs & Stratton engines into unique mechanical creations.

• The team has created a transparent engine by replacing the metal head with an acrylic head, allowing a view of the inside.

• They demonstrate the four strokes of the engine: intake, compression, power, and exhaust, which combine to create the engine's constant sound.