mechanical valve demo
by klond
uploaded 2016-08-16
stock aircraft
#piston #engine #valve


  • Type: SPH
  • Class: aircraft
  • Part Count: 198
  • Pure Stock

^ 2 stroke 2 cylinder with sliding valves. Power strokes are 180 degrees out of phase for smooth power. Paddles for flywheels to smooth out power more and prove that the system has a little torque.

I’ve chosen 2 cylinders to keep complexity down and it makes adjusting the valves easier. Since there are 2 dead spots (tops and bottoms of strokes) I’ve included a starter motor to get it going (sepratrons I think they’re called).

Valve timing is also exactly 180 degrees out of phase of each cylinder but because the rocker pivot is offset is has a slow-open, fast shut behavior. Of the 360 degrees of valve movement, I had to choose what percentage is open vs closed. I think just shy of 180 degrees open (from top dead center to bottom dead center) would provide the most power, but the valves are not digital, meaning there is a grey area when it’s kind-of-closed, this is where inefficiency and power loss happens.

You’ll probably see some piston slapping. I’ve actually used this to an advantage. The jets are located slightly rearward and the pistons fall to the back wall on their power stroke so they’re in the power stroke for just a little while longer than they would be without the slap.

This tech puts us really close to having a working steam locomotive, but by the looks of it a Proud Mary might be easier :)

Shoutout to the turboprop guys for all the great examples of what different part combinations are capable of.

Ver. 1.1.3

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