Friction Fitting Engines?

An interesting response from Fred Schector on YORF:

"If its hard to insert the motor, it is going to be just as difficult getting it out!"
Posted by JeromeK99
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Response from Fred Schector:
"Not with black powder motors.
They are swollen from the loading process.

After firing, they get smaller because the cardboard casing can relax back toward the original unloaded and unstretched size.

That is why I never put the masking tape for friction fitting on the middle or lower end of the motor casing since that is swollen and it will shrink and allow the motor to eject after firing. I install masking tape around the top of the motor casing and it extends up and over the top edge where I can roll it over to form a smooth lip that will not roll up on itself (which can make the motor get stuck in the body tube very badly)."
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Great Advice, Fred!
A few years back Fred recommended pulling friction fit engines immediately after a flight.
I'd always thought that engines would expand after a flight, most things do expand when heated. I would wait until the engine cooled before trying to pull it out.

Not so with a LPR black powder engine casing!
It makes sense that immediately after the engine is fired the bulging casing would contract after the compressed propellant is burnt out.
The next time you fly a model with a friction fit engine, try pulling the casing right after the flight.
Chances are, it'll come right out without pliers or tamping with a dowel.