Inventor > Pro-E > Solidworks > MasterCamX > Solid Edge
Nice work on the engine so far man. I'm sure you'll get all the details properly ironed out as long as you don't burn out on the project
Now that I have a job where I use ProE, AutoCAD and MasterCam all day I don't really have the motivation to do this stuff at home. But I used to go crazy with details in my models... I only started the internals when my computer decided it couldn't handle the file any more. Never got a chance to render with textures/animation
Here's something that I did back in the day when I had free time (3dsMax):