Step One: Enjoy a bottle of wine with friends, and save the cork.
Step Two: Wait until sober, and drill a small hole throught the cork, lengthwise.
Step Three: Fit a balloon over one end of the cork, and whittle away the other end if necessary until it can by pushed snugly into the spark plug hole.
Step Four: Hold the cork to stop it blowing out, and spin the engine. Do this on each cylinder - you've probably guessed by now.....the balloon should inflate with equal vigour on each cylinder. A limp balloon signals trouble ahead!
For more accuracy, go and buy a good-quality compression tester - they never lie!
This would be where the friends come in handy.
Otherwise a bit more whittling and it should be possible to screw some of the cork into the plug thread.
No idea if that would be enough to hold it but a bit of experimentation would find a solution.
I'm thinking the balloons would just pump up as they wont be pushing air back with as much force as the engine is pushing it in.
Still sounds entertaining though .
Why not attack an old spark plug I'm sure it should be possible to break the ceramic parts out to make a balloon adapter, just make sure no shrapnel falls down the plug hole.
This message board is like a family - you can't choose the other members!! But remember engine oil is thicker than water.
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