Add at least 2more pistons. Either inline or next to the 2 you have. Even a 3rd would be better than 2. When you only have 2 pistons, you have a timing issue where both are at the full range of motion that provides less power. Adding 1 or more pistons will allow you to offset the starting rotation so that atleast 1 piston is always closer to the center where where they provide the most power. If you have 3 pistons it makes it a bit more difficult to get even timing but you can try -.33,0,.33 and should have much better results. With 4 pistons have starting rotation of 0,.25,.5,-.25 You may want to try to get a bit more heat into the boiler when you are at full throttle and less heat at 0 throttle. You want to have a slightly climbing pressure at just below full throttle and even pressure at full throttle. Increasing pressure means you are making steam, decreasing pressure means you are losing steam. Make sure you have enough exhaust for steam exiting the pistons, any back pressure will slow them down. I added some pumps to mine with better exhaut ports and they worked much better at higher throttle settings. As long as you can make as much or slightly more steam than you are using, and have a good timing setup you should see fairly consistent rps. The timing and having good exhaust is the key. If you can fit 5 pistons in there, that would be ideal. They do not have to be in line, you can do a 2 ,2, 1 configuration with pipes connecting them and have the same results as an in line configuration as long as the steam is connected right and timing is set up like an inline configuration. For 5 pistons, you want 0,.20,.40,-.40,-.20. Rotation offset.
You could change the piston offset to -12 on one and 12 on the other it should allow a smoother movement. I had that issue with 3 pistons I changed the front one to 25 and the back one to -25 and left the middle one at 0 it got rid of the choppy power.
Add at least 2more pistons. Either inline or next to the 2 you have. Even a 3rd would be better than 2. When you only have 2 pistons, you have a timing issue where both are at the full range of motion that provides less power. Adding 1 or more pistons will allow you to offset the starting rotation so that atleast 1 piston is always closer to the center where where they provide the most power. If you have 3 pistons it makes it a bit more difficult to get even timing but you can try -.33,0,.33 and should have much better results. With 4 pistons have starting rotation of 0,.25,.5,-.25
You may want to try to get a bit more heat into the boiler when you are at full throttle and less heat at 0 throttle. You want to have a slightly climbing pressure at just below full throttle and even pressure at full throttle. Increasing pressure means you are making steam, decreasing pressure means you are losing steam.
Make sure you have enough exhaust for steam exiting the pistons, any back pressure will slow them down. I added some pumps to mine with better exhaut ports and they worked much better at higher throttle settings. As long as you can make as much or slightly more steam than you are using, and have a good timing setup you should see fairly consistent rps. The timing and having good exhaust is the key.
If you can fit 5 pistons in there, that would be ideal. They do not have to be in line, you can do a 2 ,2, 1 configuration with pipes connecting them and have the same results as an in line configuration as long as the steam is connected right and timing is set up like an inline configuration.
For 5 pistons, you want 0,.20,.40,-.40,-.20. Rotation offset.
You could change the piston offset to -12 on one and 12 on the other it should allow a smoother movement. I had that issue with 3 pistons I changed the front one to 25 and the back one to -25 and left the middle one at 0 it got rid of the choppy power.
Put a valve that controls the steam going into the engine, fidle around with the valve 0,3 - 0,55. Should help with the stuttering of the engine.
First