Engine Selection Advice You must consider the following when selecting an engine: Application: e.g. water pump Hp or kW required e.g. 20 hp Speed e.g. 2500 rpm Direct-coupled or v-belt e.g. direct-coupled by a flexible coupling Ambient conditions e.g. up to 40c, 30% humidity Site conditions e.g. undercover on farm site Duty – continuous or intermittent e.g. continuous 2500 hrs per year Other factors e.g. Side loads, vibration, electrics, maintenance and service plan, noise levels, shock loads, exhaust emissions etc. Standard conditions: 20°c ambient temperature, 30% relative humidity at 100 meters altitude. Gross intermittent rating: 1 hr rating based on the engine without cooling fan, air cleaner, muffler, but with alternator...