31. The next type was thickened at the exhaust ports and are also known by some people as Mk2. 32. In full-size engines, the steam and exhaust ports are usually built into the pivot ( trunnion ) mounting. 33. All exhaust ports now faced rearwards. 34. The head used during this time was the so-called " rectangle port ", named after its exhaust port shape. 35. The products of the flame are finally vented out of the detector through the exhaust port ( J ). 36. However, the risk of excessive compression often results in small auxiliary exhaust ports being included at the cylinder heads. 37. The lower crankshaft ran eleven degrees behind the upper, meaning that the exhaust ports opened first, allowing proper scavenging. 38. The exhaust port opens while there is still significant pressure in the cylinder, which drives the initial outflow of exhaust. 39. Fresh air cleanses the cylinders of remaining exhaust prior to the exhaust ports being covered by the rising lower piston. 40. This approach allowed Mazda to eliminate overlap between intake and exhaust port openings, while simultaneously increasing the exhaust port area.
