limited production run

[HyeeWang]

Nineteen R engines were assembled in a limited production run between 1929 and 1931.
What is " limited production run" ?Thank you!
context: http://en.wikipedia.org/wiki/Rolls-Royce_R

 

[teksch]

Rather than produce a large number of the engines, there were only a small number of the engines made. Sometimes there is a limited production of an item due to a weak demand or because there is a limited need.

 

[HyeeWang]

Thank you! teksch.

What does "run" mean there? What is its usage? whether it can be omitted?