OK, so I decided to do a simple internal combustion engine in LBP, and it was also my first real attempt at making something a little complicated.

Now, the only motorized bolt is the one on the starter (which comes out when you pull the switch). The back part of the starter with the sponge slides out to engage the motor bolt itself and spin the gear, which then makes contact with the cog/flywheel/crank.

The top of the clinder (on the triangles) and the top of the piston heads have proximity keys on them, and when they come within the right radius of eachother, emitters shoot out explosive boxes at the piston heads. The explosion forces the piston downward after it reaches top dead center (timing is adjusted by the location of the proximity marker on the triangles), which then drives up the next cylinder for ignition.

The engine stopper is a little trickier. It uses a bolt connected to a smaller cog, and the bolt is tightened to level 10. It will effectively stop the engine, but you must hold onto the switch to keep the engine lock engaged. Sometimes you might stop when the keys are in promimity to one another, and I'm still working on that one, but it will keep exploding until the pistons are in a neutral position. It's a bit of trial and error I guess you can say.

The pistons (usually) remain in position after you disengage the engine brake. This allows you to go back to the starter and pull the switch to start the engine again if you'd like. To keep everything running smoothly, the parts that rub on eachother (cylinder walls and pistons) are made of glass to simulate lubrication. Piston rods are just wood using the flat layers in front of and behind the flywheel. And just like real life, make sure you disengage the starer appropriately, or you're going to throw out the starter gear.

Some comments based on other designs I've seen online. This is the fastest, non-assisted piston set up I've seen. Some people use the motor bolts to drive the crank, some use rockets to drive up the pistons, and others have a dual combustion setup that shoots explosives on the top of the cylinder and underneath the piston (to drive it back up), and are still slower than mine. And so far, I think my timing of the explosives is about the best, too.

lol, cool

I also updated my engine with another switch that's tied to the other two that lowers and raises the ignition triangles, so when you use the starter, it drops the ignition along with it and when you kill the engine with the brake, it also raises the ignition so it doesn't keep firing when you stop the engine from spinning at certain parts