# Volume versus temperature

1. Jan 5, 2013

### spaghetti3451

1. The problem statement, all variables and given/known data

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.)

2. Relevant equations

Relation of volume to temperature

3. 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???

2. Jan 5, 2013

### 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?

3. Jan 5, 2013

### 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.