Model includes: engine casing & oilpan, crankshaft and pistons and connecting rods, essentially the whole lower side of an engine. The idea is to understand and demonstrate how an engine moves and converts linear power to rotational power. This is my largest model to date. Some additional hardware is required: 8 3x10mm screws.

1. connect “oilpan 1” to ”oilpan 2" with the provided “connecting screw” and “connecting nut”. Do the same with the “engine casing 1” and “engine casing 2”. The engine casings are very large prints, make sure that nothing warps or that your filament doesnt run out.
2. slide both “spacer for large crankshaft” onto either end of the “crankshaft” and lay it into the semicircular holes in the now connected oilpan.
3. take one “lower con rod” and one “upper con rod” and screw them together with 2 of the 3x10mm screws. Make sure that the crankshaft is in the large hole between these two pieces and can freely rotate. Repeat this process 4 times in total.
4. take one piston and, using a “piston screw” and “piston nut”, connect it to the connecting rod via the smaller hole on top. Repeat this process 4 times in total. Congratulations! You now have a complete crankshaft assembly.
5. take the two, now connected, engine casing pieces and turn them upside down, so that the semicircular holes are facing upward. Lower the crankshaft and all 4 pistons into the engine casing
6. place the oilpan onto the crankshaft assembly and the engine casing. The crankshaft should now be able to freely rotate but also not move side to side, check that this is the case.
7. take 4 “oilpan to casing screws” and 4 “oilpan to casing nuts” and connect the oilpan to the engine casing. The large pieces are designed in such a way, that the nut fits into the oilpan and the screw comes in from the top through the hole in the engine casing. Once these two big halves are connected, you have my full model of an inline 4 cylinder engine.

FYI: the holes in the top of the engine casing are there in order to allow a cylinder head, which is still in the works, to attach to this model.