Comments by "Keit Hammleter" (@keithammleter3824) on "Analyzing The Split Piston Engine in 3D. 🤯 Dual Cycle D // 2 and 4 Strokes Combined // 3D Animation" video.

  1. Whoever wrote the script thinks 2-strokes all work the same way as lawnmower engines. Not so. Large 2-strokes used in railway locomotives, truck & bus engines, and ship main engines all use forced induction by an external blower and don't cycle air or fuel/air mix though the crankcase. The design presented in this video seems a daft way to make an engine to me. Principal defects are the difficulty in accelerating the upper piston down fast enough, considerable cam stress, and, given that a conventional engine has less than ideal volumetric efficiency, due to the increased piston speed, the volumetric efficiency in this engine is going to be exceptionally low. If the upper piston seats just right at the right time on the bottom piston so that the bottom piston's rods take the power stroke load, during warmup that won't be the case, due to thermal expansion/contraction. Depending on various factors, that means full power transmitted via the cam, or the pistons destructively hitting each other, or both. However, some of the stated disadvantages given in the voice over aren't true. Eg it is claimed that oil spray cooling of pistons is mandatory, but truck and large engines all use spray cooling anyway. It isn't needed in car engines because a car engine is never run at full power for more than a few minutes.
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  2. You would need an immense amount of air pressure. The inertia in the upper piston and its conrod is the major issue with this engine. In normal engines the con rod length is kept as short as possible to minimise bearing loads for this reason.
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  3.  @sancharino4672  What makes you think it was running at half the normal RPM? If it was, there could not be ANY power output increase, only a decrease because of reduced volumetric efficiency, and more loads on more bearing surfaces.
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