Combustion Visualization inside a Flathead
 

Hope you guys don't get too upset with starting this thread since it's not a restoration project. These are too cool though to not share. Everyone that has ever built an engine has to always wonder exactly what is going on inside the darn thing when she's fired up. Secret revealed...

The engine shown is just a horizontal shaft utility engine but same thing as a flathead scaled down.

https://www.youtube.com/watch?v=jdW1t8r8qYc
https://www.youtube.com/watch?v=rURHVLM9nxs
https://www.youtube.com/watch?v=31mtOdHGbB4
https://www.youtube.com/watch?v=e_jrAoJp8XE&t=209s
https://www.youtube.com/watch?v=xflY5uS-nnw
https://www.youtube.com/watch?v=rXygd_cR8dY