Cirrus Mark III.

Extract

It may be of interest to give a resume of the Cirrus engine from the time of its conception up to the present period. The main idea actuating the designer was to produce an engine whose features would be reliability, low maintenance costs, and capacity to run for long periods with little more attention than a motorist gives to his car engine, and also so constructed that the average owner driver or motor mechanic could readily understand it and maintain it in perfect running order. The first Cirrus type engine was completed in May, 1925, and was submitted to the 100-hour Air Ministry type tests. These tests were successfully passed. The series of tests laid down by the Air Ministry Form A. P. 840 are of a most exacting nature.