Yeah, I like cutaway mechanical stuff, too, but when dads take over the kid's projects, the goal is to win.
Exploding something is great, splashes and smells are impressive, too. How about a perpetual motion hoax? Unless you have a real one, then my hat's off to you, sir.
Hey, bikes, kid, dad, what fun.
This is like the pinewood derby where you know those kids didn't make those things. Even the inclusion of a strobe light will increase your chances of winning.