thank you What helps me is trying to find a minimum face density which allows me to define all the details I want to pack into the geometry. I think about that a lot before I even start to model. I would estimate that gathering references and planning topology took the same amount of time - if not longer - than modeling. Regarding the modeling that’s basically classic box modeling… starting with primitives, joining them and using the knife tool a lot.
The workflow I used for the engine was starting with traces of the gaskets (you can find them on the picture below) which were aligned in the side view. From there, I modeled outwards, mostly extruding and adapting geometry on the fly.
Talking about it I cannot stress enough the importance of references, especially if you don’t have access to blueprints.
Here’s a screenshot of my references for the engine alone:
One more thing: Since I’m not bound to deadlines, I really like to model as clean as possible, avoiding any trickery. I don’t think it would be advisable to flesh out every small detail in a production setting where time is always short. Memory wise, I’m quite happy with the geometry right now: polycount is ~7000 for the valve cover, cylinder head and cylinder each and 15000 for the crankcase. The renderings were made with a subdiv modifier at level 2, totalling at about 600000 polys including all the small pieces.