One of the best things about growing up was the Lego universe. We've all had a pile of bricks spilled out on the floor of our room, a sea of landmines for any parent who dared enter, manically building some wild hot rod contraption. While we take Legos seriously, the Lego Pneumatic Engine (LPE) builders take it to an entirely different world.

The LPE, is a sect of Lego modelers who use Lego's workhorse pneumatic piston and valve pieces to assemble functioning engines. Many are built as models of larger engines, but for the most part, they are custom designs. LPE engines are built as single-cylinder thumpers, to high-revving V8s, all the way up to 64-cylinder radial engines, like the one used in this full-size Lego car.

Nicjasno is one of the big names in LPE building. With previous LPE builds gathering some fame, he's made a small business out of shipping hand-built LPE engines for other builder's projects. What's involved here is a fascinating build of an engine with components that seem recognizable to us, though very alien. For instance, check out the blue "camshaft" used for the air switches in this video.

With this V8 built by an LPE builder known as Liftingbricks, we still have eight cylinders sharing one common crank. In the middle is a camshaft, of sorts, that actuates a set of sliders who act on the pneumatic air switches, controlling "ignition" timing for each cylinder. These are commonly used in custom Lego model cars with functioning transmissions, suspensions, and steering systems.

And finally, of course, there's a quest for maximum speed, with several of the LPE builders going for maximum RPM over anything else. Here, modified valves and pistons seek to eek as much efficiency as possible out of each engine. Due to the tachometer pickup running at 50-percent of the crankshaft speed, you'll have to double the tachometer's readout to an astounding 5,000 rpm. All of this from (mostly) off-the-shelf Lego parts.