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Is that the right video? Ah...i see it just got fixed.Bill
Is that the right video? Ah...i see it just got fixed. Nice runner too!!! Is there no exhaust valve in the design or is it just something you haven't added yet?Bill
The last part of the assembly ..........Added a wood base and name tag to finish up.To make the engine run since it has no exhaust valve and air is trapped in the cylinders on the up stroke I added a bleeder hole into the cylinders and capped off with two button head socket head screws that are drilled thru 1/8" diameter. Of course this allows a continuous bleed of air from the input air , but causes no problems. It actually adds to the sound of the engines running.With its size this engine uses a bunch of air, but runs nicely at low speed. Top RPM is about 265. In the video a last minute addition is the gear on the other end of the crankshaft. Item found in my " never know I might need it " drawer. http://www.youtube.com/watch?v=NGGt8h_9tQ4Thanks for all the views and comments ! All appreciated !
Quote from: toolznthings on March 13, 2018, 04:44:02 PMThe last part of the assembly ..........Added a wood base and name tag to finish up.To make the engine run since it has no exhaust valve and air is trapped in the cylinders on the up stroke I added a bleeder hole into the cylinders and capped off with two button head socket head screws that are drilled thru 1/8" diameter. Of course this allows a continuous bleed of air from the input air , but causes no problems. It actually adds to the sound of the engines running.With its size this engine uses a bunch of air, but runs nicely at low speed. Top RPM is about 265. In the video a last minute addition is the gear on the other end of the crankshaft. Item found in my " never know I might need it " drawer. http://www.youtube.com/watch?v=NGGt8h_9tQ4Thanks for all the views and comments ! All appreciated ! Looks and runs great, nice slow speed running. Reading others comments I'm thinking that the double sizing is the reason you need the bleeders, you didn't make the exhaust holes big enough to let all the air out.Doubling the size of the cylinders and the stroke more than doubles the volume in the cylinders, it 8 times it. If my math is right, the original design was about 0.7 cu inches per cylinder. Double the radius and the length, and now you get about 5.5 cu inches per cylinder. That's a LOT more air/steam to let out.But, doubling the size of the exhaust holes only doubles the area allowed for air/steam to escape, so more air/steam is trapped in the cylinders, causing the backpressure. And to make matters worse, Elmer's design had a slot, while you drilled holes (which I think look much nicer, BTW), so your exhaust port probably isn't even twice his.Not sure if making larger holes will help (or is even practical).Thoughts? Disagreements?
So now the inevitable question....What's next Bill