Subaru EJ20 Boxer engine!!! It's fully functional as in all parts move as intended in the real thing. Do not confuse it with a real engine, as this is not. This engine is slightly harder to print and assemble than my Toyota 22RE engine. So it is best to print or familiarize yourself with my previous models if you choose to print this one. The scale is once again 35% of the original which seems to be a good size for printing and finding fasteners that work and look right. The tolerances are a little tighter and depending on your printer the crankshaft might take some tweaking to get it right so that there is not interference while rotating. Complete hardware kits are now available. I partnered with MakerRX. Head over to their page to purchase my kit. https://www.makerrx.com/products/mrx2 Kits include all non printed parts, 500 rpm dc motor, speed controller, power connectors, and DC power supply.