Hardware · mod

A 3D-printed engine gets five valves per side

Alexander's Laboratory squeezed ten valves into a small engine's cylinder head, using large wood screws as the valves and one camshaft driving all of them.

Build sheet

Base: 3D-printed ICE
Head: CNC alu + nylon hybrid
Valves: 10 per cylinder (wood screws)
Camshaft: Original, with 5-valve adapter

Can I build this?Expert · AI 2/5 · $300–800

Difficulty: Expert
AI-buildability: 2/5
Time: A month or more
Cost: $300–800

Parts

worm gear

Tools

CNC mill3D printerlathewood screwsengine tuning equipment

Starter prompt

Based on "A 3D-printed engine gets five valves per side" on Afterware: https://afterware.xyz/p/a-3d-printed-engine-gets-five-valves-per-side

I have a small 3D-printed single-cylinder four-stroke engine with a four-valve head. Help me design a new cylinder head with five intake and five exhaust valves that is driven by the original camshaft through a rocker or pushrod adapter. Start with the valve spacing and the timing math for the adapter.

Estimates based on the original write-up. How AI-buildability is scored. Building with an AI assistant? Connect it to Afterware (free MCP server).

Story

Most engines make do with the fewest valves they can get away with. This one runs ten. The maker swapped the stock four-valve head on a largely 3D-printed engine for a new one with five intake and five exhaust valves per cylinder, a layout inspired by the 20-valve Yamaha FX750.

The valves are large wood screws, chosen after checking they could handle combustion heat. Ten of them barely fit into a head made from a CNC-machined aluminium and nylon-printed hybrid. The original camshaft stayed in place, driven through an adapter that actuates all five valves on each side at once. After some troubleshooting and tuning, the engine runs well.

Worth stealing: the valve-count trick is a cheap way to test a head design, since screws and printed parts cost little. The video doesn't give power or efficiency numbers against the four-valve head, so the performance question is still open.

Resources · 1

Build video