This is just crazy and all kinds of awesome.
There is a 14 part Youtube series that follows this build from concept, development and fine tuning to the final paint and demonstration.
If you are interested and have some spare time I highly recommend watching them all.
I literally stumbled on this by accident, watched the very first one and was instantly hooked just by the concept alone.
The young man in this video basically designed and built the Governor that is the heart of the whole thing along with guidance from the old experienced hand who I see has several original hit and miss engines laying around in the back ground and is the Youtube Channel creator, 805ROADKING.
He is the Evil Genius who came up with the idea in the first place.
The link to the whole series is right HERE.
This is the final video of the series.
The modifications they did to this 1951 6-S Briggs and Stratton lawn mower engine are something to behold.
Just to One Up himself I guess, his next project is covered in a 24 part series. He took 4 of those old engines, mated them all together end to end and then he and Mike made an Inline 4 cylinder that sounds exactly like an old Model T engine. His attention to detail is so acute the thing looks like it came off the Briggs and Stratton factory floor.
It is incredible.