My next build--A cross beam vacuum engine

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Brian, can you post the dimensions of that revised cam and also say what OD the bearing follower is.

I don't know what software you used to create its timing but it looks like it is designed like an IC engine in that the lobe of the cam will open the valve. As you have a beam that will reverse things so your narrower looking revised cam will actually open he valve for longer not less time than I suggested
I agree. I am no expert on these engines but I think that the cam is the problem. As I said above the valve action starts as soon as the intake hole is starting to open and is closed when it is completely closed. Don't give up yet.
Brian, i wont mention this again as im sure you are tired of me saying this. but you laped in your piston to the cyliner with 600 grit (while cold). i believe that was how you did your flame eater engine as well and you couldnt get it to run. what i found was do not lap the piston to the cylinder. rather heat the cylinder up and then measure / cut your piston to fit the cylinder when its hot. reason is that the piston is to small once the cylinder heats up and doesnt have enough sealing power to get the suction it needs because the cylinder expands more than the piston does. once you do this, with the piston in the cylinder hot it should be able to move, once the cylinder cools down the piston will be siezed up and wont budge. thats how it works for mine. the little engine in my avatar photo is the one im talking about (built from your plans). graphite piston, ss cylinder. and when i say heat it up -i mean by the denatured alcohol (also called methalated spirits) burner that you will be using to run it on.

once you have the piston where it will move freely hot but seized up when cold then hopefully it will run for you
Jason---This is the new cam I made. The follower bearing is 1/2" o.d. The beam is pivotted 1/3 way along the bottom so it actually gives a 2:1 ratio from the end the crankshaft lifts to the other end that opens the flame valve.---Brian
Hi Brian !
Just personal opinion
If it's my engine and it doesn't run, I'll put it aside and move on to a new project with new parts
Because it's beautiful and I will come back to it any time when I have new ideas, new make it run . And it will run

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