Extruded alu

Yes. Rotax 914

OK, I see.

Well just open it from the inside

Higher RPM is better. Low revving engines are obsolete. If you think 5500rpm is fast, what about turbines that spin at 30-50000rpm?

@@chippyjohn1 Turbine engines aren't converting the up and down motion of pistons into the rotational motion of a crankshaft

@@Agislife1960 Look, an IO360's pistons are under about 2.5 times the stress of a Rotax 914 because of their mass. The pistons in both engines travel about the same speed, but because of the mass of the big merican engine, they are under far more stress. One of the many reasons big old engines arent used anymore. A lesson in physics incase you don;t believe me. Raise a golf ball above your head and drop it, then raise a bowling ball and drop it. Let me know which one hurts more.

@@chippyjohn1 Your last comment mentioned Turbine engines which isn't a good analogy when referring to the problems that must be overcome by piston engine designs and because the laws of physics don't change large low revving engines will never be obsolete, a Lycoming 580 engine will never reliable run at 5000 RPM

@@Agislife1960 FACE PALM. It's not about RPM, its about piston speed and reciprocating mass. An IO580 has a piston that weighs about 2500grams while a rotax 914 piston weighs about 500g. Both are traveling at the same speed, so the IO580 is under far more stress. You americans keep imagining large engines revving high. Smaller engines are able to rev higher safely. A little RC nitro engine can rev comfortably at 30-40000 rpm because of its short stroke and low piston mass. Its basic maths. Did you try the golf ball/bowling ball test? Large piston engines such as lycoming and continental are obsolete because they weigh far more for the same amount of power as a smaller engine.