I am quite possibly headed for failure but I intend to give it a go and that is to design and make an atmosperic engine! (Flame Licker)
Most everyone I see on this and similar forums when they make a flame licker they make a very small machine, I admire their clever and precise workmanship and doubly so if the engine actually runs. For my part I want to make it easier for myself by making something a bit bigger so I am starting with a bore of about 40mm.
If I am not mistaken the ratio of circumference to area of a circle varies by a square law so a bigger diameter piston has less peripheral friction for its size than a smaller one.
So far I have turned a cylinder and a piston, the cylinder is steel water pipe and the piston is a turned down end fitting for the same type of pipe and I am hoping the expansion ratios are somewhat similiar. The piston is an easy sliding fit and I turned a couple of grooves in it which seem to give a rather nice seal when partially filled with powered graphite.
So that is the piston and cylinder, I have some bigger diameter water pipe that I will make into a water jacket. I think a water jacket for a flame licker would make for easier starting if it is filled with boiling water before trying to start.
I will have two ports, one a simple flap valve which will open whenever the bore pressure reaches atmospheric, this will be the exhaust valve. The second port will be the input port which will be operated by the piston to give a sudden opening at TDC and an equally sudden closing near BDC. The aim of this arrangement is to reduce the chance of exhaust gases mixing with the hot input gases.
Most flame lickers seem to have the flame exposed and just positioned near to the cylinder port, I will make a small chamber which will be filled with hot gases from the flame and the cylinder will draw from this, this also is intended to reduce 'room air' mixing with the flame gases.
Work continues.
