Sure, the key is to keep friction low and avoid heat buildup. Use low‑friction bearings, make the pistons almost air‑tight to prevent noise from combustion, and run the engine at a steady rpm so it doesn’t whine. Add a bit of oil to the valve train, but keep it light to avoid splatter. And if you can run it on a clean, dry fuel source, you’ll cut the hiss from the fuel lines. Keep it simple, keep it quiet.

Got it. Just keep the seals tight, check for leaks, and run the test in a quiet room before the real run.