What matters is how the ports “feel” to the air. I port for “smooth.”
The tools I used on this job:
Shop-vac-to-port-adapter, various die grinders, pressure regulator.
The LONG burr has a metal sleeve around it which I use to guide the cutter to where I want it – I hold the metal sleeve.
Only smooth the short-side. Significant cuts to finish the incomplete factory throat cut. All “edges” removed. Burr finish only.
To the haters: the level of work depends on the application – this is more than fine for a 19′ road sofa with a 2-barrel and single exhaust.
3-angle valve job completed. Though, truthfully, any valve job should be at least 3-angle.
Valve Guide Boss Cutter I made years ago cut down the valve guide bosses, so I can fit modern positive lock valve seals (part number below), which it turns out are harder to find than different part numbers. These are quite a small body diameter.
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