1930's Opposed Piston Aero Engine Design Revived? Jumo 205 & Gemini Explained

Was the Jumo 205 simply too advanced for it's time, to be realised 100 years later how good it actually was? The Gemini Opposed piston engine is a relatively new engine based on the 1930's design, but is the opposed design any good as a modern efficient aero engine? Data sources: https://web.archive.org/web/20101206130000/http://ppdgemini.com:80/_PDF/Weight_Comparison_6-08_B&W.pdf https://web.archive.org/web/20101206125839/http://ppdgemini.com:80/_PDF/Gemini_100_Spec_Sheet_1-10-09_B&W.pdf https://www.flyrotax.com/products/912-is-sport-isc-sport Follow me on Instagram: https://www.instagram.com/lets_go_aviate/ IMAGE ATTRIBUTION Junkers Jumo 205 Berlin museum-author W2k2 (https://creativecommons.org/licenses/by-sa/3.0/deed.en) no changes Junkers Jumo 205 at the Polish Aviation Museum-author Zala (https://creativecommons.org/licenses/by-sa/4.0/deed.en) cropped JU-86 HB-IXE-author ETH-Bibliothek Zürich, Bildarchiv/Stiftung Luftbild Schweiz (https://creativecommons.org/licenses/by-sa/4.0/deed.en) crop+zoom Junkers Ju 86 bomber-Unknown author, Post-work Cobatfor (https://creativecommons.org/licenses/by-sa/4.0/deed.en) crop + zoom Dornier Do 18-Unknown author, post-work Cobatfor (https://creativecommons.org/licenses/by-sa/4.0/deed.en) no changes Do 24 V-1-author Karl Kössler (https://creativecommons.org/licenses/by-sa/3.0/deed.en) no changes Napier Deltic-author Chowells () (https://creativecommons.org/licenses/by-sa/3.0/deed.en) crop+zoom Junkers Jumo 205 cutaway-author Thomas Vogt from Paderborn, Deutschland (https://creativecommons.org/licenses/by-sa/2.0/deed.en) cropped Junkers Jumo 205 partial cross section-author Thomas Vogt from Paderborn, Deutschland (https://creativecommons.org/licenses/by-sa/2.0/deed.en) crop+zoom+overlaid arrows&text Bosch EV14 injector https://s4wiki.com/wiki/File:Bosch_EV14_injector_sizes.jpg (https://creativecommons.org/licenses/by/4.0/) cropped 3 injectors out Junkers Jumo 205 Muzeum Lotnictwa Polskiego-author Zala (https://creativecommons.org/licenses/by-sa/4.0/deed.en) crop+pan Jumo 207 B-2-author Duch (https://creativecommons.org/licenses/by-sa/4.0/deed.en) no changes Jumo 207 front-author Bergfalke2 (https://creativecommons.org/licenses/by-sa/3.0/deed.en) crop+pan Junkers JUMO 211 cross section-author Triple-green (https://creativecommons.org/licenses/by-sa/2.0/deed.de) cropped,text+arrow overlaid DB 601 cross section-author Bjoertvedt (https://creativecommons.org/licenses/by-sa/4.0/deed.en) text + arrow overlaid Jumo 205 front-author hmboo Electrician and Adventurer (https://creativecommons.org/licenses/by-nd/2.0/) no changes Jumo 205C-author Duch (https://creativecommons.org/licenses/by-sa/4.0/deed.en) cropped Junkers Jumo 210-author W2k2 (https://creativecommons.org/licenses/by-sa/3.0/deed.en) cropped Junkers Ju-86 B-1-author Swissair, Fotograf (https://creativecommons.org/licenses/by/4.0/) crop+zoom Inline 6 marine crank-author Marco Bernardini (https://creativecommons.org/licenses/by-sa/2.0/) cropped Jumo 205 at Kosice Aviation Museum-author User:VargaA (https://creativecommons.org/licenses/by-sa/4.0/deed.en) crop+zoom arrow overlaid Dornier Do 24 drawing-Unknown author, post-work Cobatfor (https://creativecommons.org/licenses/by-sa/4.0/deed.en) own drawing overlaid Jumo 205 cross section closeup-author Ricardo Reis from Lisboa, Portugal (https://creativecommons.org/licenses/by-sa/2.0/deed.en) cropped+overlaid text Jumo 207 cross section-author Bergfalke2 (https://creativecommons.org/licenses/by-sa/3.0/deed.en) overlaid text OHC head-author Pᴀᴜʟsᴛᴇʀ2 (https://creativecommons.org/licenses/by-sa/3.0/) overlaid cross Dornier Do18 engine installation-Unknown author, post-work Cobatfor (https://creativecommons.org/licenses/by-sa/4.0/deed.en) overlaid text Continental O-200-author YSSYguy at English Wikipedia (https://creativecommons.org/licenses/by-sa/4.0/deed.en) no changes VIDEO & ANIMATION ATTRIBUTION 120hp Ford B-Max Ecoboost animation by Motor1 (https://youtu.be/LNfQqHooQZI), license CC-BY Two-Stroke Engine (crossflow) animation-author A. Schierwagen using OpenOffice Draw (https://creativecommons.org/licenses/by-sa/3.0/deed.en) no changes Inline 6 animation-author MichaelFrey (https://creativecommons.org/licenses/by-sa/4.0/deed.en) cropped, rotated & further animation added Diesel engine Junkers Jumo-205 moving model-author 3dhdscan on sketchfab (https://creativecommons.org/licenses/by/4.0/) slightly cropped ME-262 WITH JET PROPULSION POWER PLANT by PublicResourceOrg (https://youtu.be/vLMU_r7A4UQ), license CC-BY Inline 3 animation-author MichaelFrey (https://creativecommons.org/licenses/by-sa/4.0/deed.en) cropped, rotated & further animation added Chapters: 0:00 Unconventional Engine Design 0:34 1.Emergence of the Opposed Piston Engine 3:12 2.Jumo 205 Design : Layout 4:11 3.Jumo 205 Design : Efficiency 9:47 4.Jumo 205 Design : Vibration 12:28 5.Jumo 205 Design : Lubrication 13:06 6.Jumo 205 Design : Shared Cylindder 15:00 7.Jumo 205 Verdict 16:38 8.Superior Gemini