This is a 2.5cc gas RC engine. This is also a complete parts motor that I have been working on for a while now. Some parts need supports and others you can get away without using any supports, I will leave that up to you. You'll need to sand the parts down to match so that the better your 3D Printer is calibrated the less you'll need to sand. Have fun with printing this if anybody will that is. Mine is printing right now and I will update it with photos when I am done.