The engine indicator records cylinder pressure change in internal-combustion engine, reciprocating steam engines, and air/gas compressor. By monitoring pressure changes in each cylinder, system can assure the operation efficiency and also used for the calculation of horsepower. This economical mechanical indicator is widely utilized for marine internal combustion engines with easy measurement process and high reliability. Besides the one which plots a curve on recording chart paper, a pressure indicator which can easily and quickly measure the maximum output of an engine at the site is also available. The MT pressure indicator indicates the maximum pressure so it can be easily read directly.