What Problems Can Occur When Automobile Engines Get Too Hot?

[spaghetti3451]

Homework Statement

Many automobile engines have cast-iron cylinders and aluminium pistons. What kinds of problems could occur if the engine gets too hot? (The coefficient of volume expansion of cast-iron is approximately the same as that of steel.)

Homework Equations

Relation of volume to temperature

The Attempt at a Solution

The coefficient of volume expansion of steel is 4.8*10-5(C°)-1. I don't see the relevance here of this numerical value. Do you?

The problems I could come up with:

1. The cylinders and pistons would expand and frictional forces would act between the cylinders and the pistons. This would lead to a slower rate of speed of the automobile for a given rate of fuel consumption.

2. Any others?

 

[rock.freak667]

If there is too much friction, what will happen to the temperature of the pistons and hence what can happen to its diameter?

 

[mrcotton]

How will each expand?
Look at the values of the Coefficients of Thermal Expansion in the table of the website
http://physics.info/expansion/
Why do piston rings have a gap in them?
The website talks about Concorde, I once read that the Lockheed SR-71 Blackbird dripped fuel on the runway and only after heating up and expanding was it fuel tank sealed.