# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DeFUuFlvpu8
- **Gondola URL:** https://gondola.cc/posts/71427946-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/9fd6e345f5.jpg
- **Posted:** 2026-10-04T19:02:09.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

The Toyan 28cc V8: a full internal combustion engine you can hold in two hands

A V8 packs eight cylinders into two banks set in a V around a shared crankshaft. The 28cc Toyan build scales that layout down to about 3.5cc per cylinder, small enough to sit on a desk and still run on real combustion.

How the four-stroke cycle works in each cylinder:
- Intake: the piston moves down and pulls in the air and fuel charge through the intake valve
- Compression: both valves close and the piston squeezes the charge, raising its pressure and temperature
- Power: the charge ignites and the expanding gas drives the piston down, turning the crank
- Exhaust: the piston rises and pushes the burned gas out through the exhaust valve

Each cylinder fires once every two crank revolutions, or every 720 degrees. Spread eight cylinders across that window and a power stroke begins every 90 degrees of rotation. That overlap is why a V8 runs so smoothly compared with engines that have fewer cylinders.

What makes the build an engineering lesson:
- Valve timing: the camshaft has to open and close every valve in exact sync with piston position, or the engine loses compression or valves hit pistons
- Tolerances: at this scale, small clearance errors become a large share of the total gap, so ring seal and bearing fit dominate performance
- Thermal management: there is very little material to absorb heat at this size, so cooling design decides how long the engine survives
- Lubrication: oil film thickness becomes critical when moving parts are measured in millimeters

Building one by hand forces you to understand every subsystem. Air, fuel, spark or glow, timing, cooling, and oil all have to work together before the engine will run.

#stemantics #engineering #internalcombustion #mechanicalengineering #stemeducation

## Stats

- **Views:** 8,084
- **Likes:** 99
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- **Comments:** 3

## Tags

internalcombustion, engineering, stemeducation, mechanicalengineering, stemantics

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