My Obsession Begins
So yesterday I fell down this rabbit hole after watching some motorcycle video online. Dude mentioned a “five stroke engine” casually like it was normal, but my brain went “wait, engines only have four strokes, right?”. Couldn’t shake the curiosity so grabbed a sketchpad and cold beer.
Trash Bin Engineering
Started rummaging through my garage for anything movable. Found an old hair dryer motor, some PVC pipes from last summer’s failed garden project, and a busted lawnmower spark plug. Taped them together with duct tape like a mad scientist. Point is – I just needed moving parts to see the concept.
Figuring Out The Rhythm
Regular four-stroke goes suck-squeeze-bang-blow. Simple. But five-stroke? Had to Google that mess. Turns out it does suck-squeeze-bang-blow… then extra suck-and-blow combo using leftover heat. Makes sense on paper until you try building it.
My trash prototype kept jamming at the third stroke. Spent hours fiddling with pipe lengths until I realized the timing was off:
- Long first cylinder for combustion
- Short secondary cylinder underneath
- Weird connecting rod angles
The Lightbulb Moment
Finally got the damn thing chugging when I stuck a tiny fan on the secondary cylinder exhaust. That extra air pull created vacuum pressure without needing more fuel. The spark plug fired once but the piston moved five times – like getting extra pushes downhill after one pedal kick. Mind blown.
Why Bother Though?
After burning three fingers on hot PVC, I see why this isn’t mainstream. Yeah it saves like 10% fuel, but the mechanics are like solving a Rubik’s cube while juggling. Dropped my trash prototype twice and had to rebuild both times. Not worth it for daily drivers, but kinda cool for engineering nerds.
Left all the junk on my workbench. Might turn it into an abstract coffee table piece. At least now when someone says “five-stroke”, I won’t look like a confused golden retriever.