OHC V60 Ultramax Engine

General A Overhead Camshaft engine is an internal combustion engine with the camshaft placed in the cylinder head. The NSU Ultramax camshaft drive operates with 2 push rods, which rotate on eccentric disks. Details you can find here: https://www.printables.com/model/272096-nsu-ultramax-camshaft-drive This model has a total engine capacity of 60 cc. Choise between an open and closed design of the cylinder head. Dimensions: 185 x 103 x 173 mm. Weight: 0.36 kg. Printing and Assembly I printed the model on a PRUSA Mini, with PLA+ filament, layer height 0.2 mm. The parts should be printed on a smooth build plate, not textured. If possible, avoid elephant foot. I use Hard Plastic Glue where necessary. For 3D views, use .stl files 00… 01... 02… 03… 04… 05… . Printing and assembly in alphabetical order, A1 → J1. Instructions for printing and assembly is available for many .stl files. Post-processing As always with mechanical models, be sure all moving parts run smoothly. I use files, sandpaper and sharp hobby knifes. A few drops of motor oil may help too. Pay special attention to seams on bearings and axles. Maybe you need a 5 mm drill to widen the four valve guides in the cylinder head. Metal parts Eight M4 x 25 mm allen bolts are needed to join the cylinder heads to the cylinders. Eight coil springs are needed as valve springs, 10 mm width x 15 mm height. Wire thickness 0.6 or 0.7 mm (AliExpress). Valve timing Initial valve timing can be executed when glueing "G1 - Base Plate Ultramax" to the cylinder. Updates 19-9-2022 : Cam lift reduced from 3.5 mm to 2 mm. For a smoother run, especially when using strong valve springs.