You can make a real jet engine for five minute's work and the price of a spoonful of meths - how cool is that?!?
I doubt there's a better way to re-use all those jars under the sink. Much more fun than a trip to the bottle bank.
Step 1: Materials and equipment.
Step 2: Making it (the lucky way)
Jam Jar Jets are by no means my idea, and I knew very little about them:
Knock a hole in the lid of a jar, splash some meths in the jar, give it a shake and light the meths.
So that's what I did, and it worked first time.
After running for a short time, with a noise like an angry moped, the temperature got too high for the jar and it gave way.
That was expected.
Then I tried to repeat the thing...
Step 3: What goes wrong...
"Daddy, show us how you made the jet engine!"
"Not a problem", thinks I.
I grabbed another jar, smacked a hole in the lid, splashed in some meths and lit it.
Foosh, then nothing. It didn't work. (There's not much point watching past the first few seconds of this video.)
After some research, it turned out that the hole was too big. If you make a jam jar jet, and it goes foosh and then does nothing, like it does in the first video above, then the hole in the lid is too big. Go make another one.
If your jet lights, goes foosh, and then goes RRRR for a moment, like it does in the second video, then your hole is not quite big enough.