Suck. Squeeze. Bang. Blow.


However the title may sound, it’s not X-rated. Not even R-rated.

The last blog I wrote, I got tired of hearing myself ramble sometimes. Feelings are all well and good, and I had a lot to work through, but I ran out of things to say. I don’t want to do that this time, and I do want to start moving towards flying again, so I am going to start working my way through the various tests that people have to pass to get a pilot’s license. My license is not current, but I’m hoping to remedy that soon. I can’t take you up in a plane with me, but I can talk a lot about flying, especially about the knowledge required. This is the first of those posts. If you don’t care or aren’t interested for whatever reason, skip the posts under the “Flying” category. Otherwise, I hope you enjoy the ride!

Suck. Squeeze. Bang. Blow.

Those are the cycles of a four stroke engine. The first time I said that to my flight instructor, he just about spit his coffee across the room. I had been having a hard time remembering them, but I came across this somewhere and loved it, both for its suggestive qualities and because it was easy to remember.

Suck. Intake. The piston is near the top of its cycle. As it goes down, the exhaust valve closes and the intake valve opens. The vacuum (suck!) created by the piston moving down pulls in the fuel and air mixture. We’ll talk about leaning and enriching the mixture later, and what effect altitude has on that.

Squeeze. This is the compression part of the cycle. As the piston comes back up, it compresses the air and fuel mixture. This raises the temperature and increases the pressure of the air/fuel mixture.

Bang. Ignition, blastoff, whatever floats your boat. Or flies your plane. Whatever. The mixture we just compressed is ignited by the spark plug, increasing the pressure and shoving the piston back down again. This is where the power comes from, what makes the engine go.

Blow. Remember the exhaust valve that closed during the sucking part? It’s opening again, and the pressure forces the gasses out. The piston is pushed back up again, the exhaust valve closes, and the cycle starts again.

This is really basic. This is why, if your spark plugs are fouled, your car doesn’t work, or it doesn’t run smoothly – without the “bang” part, the piston doesn’t get shoved down and the cycle doesn’t work. This is the beginning of understanding a four stroke engine, and the beginning of my lessons for you, and for refreshing my memory, about how airplanes work and how to fly.

Welcome to my brain. Prepare to learn a bit of physics, weather, and what all of the random dials in front of the pilot do. Oh, and just to be clear, I don’t fly jets. You can make a brick fly if you put jets on it. The planes I fly are maneuverable, exciting, and responsive, and they are quite enough for me. Not that I’d object to a ride in a jet, but it’s not my cup of tea. Right now, anyway.

This is just the beginning. There’s a lot of information to get through, and if I have a hard time understanding something, you’ll hear more about it.

2 thoughts on “Suck. Squeeze. Bang. Blow.

  1. It’s one of the things I struggled with, but once I got this explanation, it made more sense. It makes me smile every time, too, which helps.

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