Inline 6-Cylinder Engine with optional Valvetrain

I have designed an inline six-cylinder engine with a functioning valvetrain featuring an overhead camshaft and overhead valves, with two valves per cylinder. Engine with and without cylinder head Recording of the valvetrain (GIF) Recording of the valvetrain (GIF) Pitons (GIF) The camshaft is driven by a belt, which can be printed from TPU. All parts, including the springs and screws, are 3D printed. The engine can also be assembled without the valvetrain. The print file includes two different engine blocks. The block without the valvetrain does not have holes for the cylinder head. Two Engine blocks Printing Material: I printed the engine using PLA and PETG. I recommend printing the crankshaft, camshaft, screws, and springs with PETG because the material is less brittle and has better layer adhesion than PLA. T