Why do aircraft radial engines have an odd number of cylinders?
Most radial aircraft engines are four-stroke motors. An odd number of cylinders can be timed so that the cylinders fire one after another sequentially as the propellor shaft rotates, rather than having a firing sequence in which cylinders on opposite sides of the engine fire in sequence. This helps the engine run more smoothly. There are typically 5, 7, or 9 cylinders in one or two rows. If there are two rows, the second row of cylinders is offset to allow air to flow between the cylinders in the first row and cool the second row – radial engines are air-cooled. The more cylinders per row, the smoother the engine and the more power per revolution. There is a practical upper limit on the number of cylinders per row because of size constraints (e.g., cylinder width, connecting rod length, cooling requirements).
RedJohn Oct 14th, 2005 Most radial aircraft engines are four-stroke motors. An odd number of cylinders can be timed so that the cylinders fire one after another sequentially as the propellor shaft rotates, rather than having a firing sequence in which cylinders on opposite sides of the engine fire in sequence. This helps the engine run more smoothly. There are typically 5, 7, or 9 cylinders in one or two rows. If there are two rows, the second row of cylinders is offset to allow air to flow between the cylinders in the first row and cool the second row – radial engines are air-cooled. The more cylinders per row, the smoother the engine and the more power per revolution. There is a practical upper limit on the number of cylinders per row because of size constraints (e.g., cylinder width, connecting rod length, cooling requirements). Like (4 people like this.) • Report No comments. Post one | Permalink Comments Add a comment… • ad_client = “ca-answerbag_html”; num_ads = “4”; type = “te
