Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hi Doug ,I don't think that the valve design on this engine is one that Stuart Turner had planed. A short story while I had my Stuart engines at the local show I was approached by a gentleman who built a 10V and he asked me how I was able to get the engine running with the supplied drawings and castings, I said that I had a learning curve but it really wasn't that hard to do .
He examined my engine a little closer and pointed out that I had the air connected to the wrong port ,he said it should be connected to the center of the cylinder casting to balance out the pressure. I said no the air goes into the steam chest and the internal D valve exposes the stem ports timed but the eccentric.
He was trying to get his engine to operate by putting air pressure into the exhaust port ,he said since he was a great engineer he was able to correct the problem .
I went to a local museum and they were trying to get a  steam engine running by piping compressed air into the exhaust to a point were they gave up and called it a vacuum engine .
Some time a lot of knowledge is lost without common sense, I suspect that the builder was frustrated and got it to run the only way that he knew how .Jeff

Great chatting to you yesterday ,god bless