Q. Are they more economical than the four valve engine?
A. No; the four valve engines are the more economical.
Q. Give a prominent example of the four valve engine.
A. The Reynold’s Corliss.
Q. What is meant by an engine running “over”?
A. The top of the drive wheel running away from the cylinder.
Q. What is meant by an engine running “under”?
A. The top of the drive wheel running towards the cylinder.
Q. Which way are engines generally run?