Ruston and Hornsby PR (Push Rod) 2 1/2hp APR Engine

These engines were introduced in 1922 as a cheaper and smaller version of the AP engines.

There were 4 sizes:

1 1/2hp ZPR

2 1/2hp APR

4 1/2hpBPR

6hp CPR

This engine is the 2 1/2hp APR

The range was discontinued in 1932