Algodoo

There are lots of little things that mke your engine slow.
-The timing is bad (make it fire AFTER the cylinder goes fully upwards, and delete the ball before the cyinder goes fully downwrds or the engine can stop. It won't lose strenght)
-The cylinders have too much movement, make the bore-stroke ratio a bit smaller
-Polygons are worse than boxes when colliding, therefore you'll lose energy. Add a transparent box behind the polygon, and make the two objects collide
-The springs should have very little damping, for example constant 5e6 and damping 0.1 (Kilinich's tech)
-You have to add "Gun tech" to "shoot" the balls or it won't work well. See vaidas's engines closer or search on Gent's scenes for a collision gun engine
-This won't change performance of the engine, but why do you use such a script to calculate RPMs? Use scene.my.RPM = angVel * 9.54

Also DO NOT USE BRAKES for the ignition timing! Use bend, because brakes unsync

Thank you The Linkage but I didn't understand everything.

- Ok, I did it

- I will see later because I saw the vaidas369 motor's use the same ratio more or less.

-I didn't understand what is the difference between polygon and boxes and what polygon and what boxes. Where do you want I put one ?

-Ok I did It

-I don't find "gun tech". And I use almost the same tech than vaidas369

-Ok I changed It still using math.toInt for a future dashboard.

-I don't really understand how Bend works so I put infinite torque to my hinge

Look, the bore-stroke ratio is ok if you want to leave it like that. for the polygon thing, you have to make balls collide with a box instead of the piston, because the piston is a polygon. And you know, i've helped vaidas with two or three engines, and I use the exact same tech he uses from longer than him, so the "gun tech" thing is two boxes that only collide with the balls, and that impulse the bll down. for example, if you add that to a 1000 Nm engine, you can get 7000 Nm. it's epic
Use scene.my.rpm = math.toInt(angVel * 9.54) if you want
For bend, it has less strenght than a brake, but even if you put infinite torque on the brake it will start moving after some time. Nothing in algodoo is infinite, mind that. Search for tutorials, bend is very useful but it's very hard to explain, and if you have bend and brake, bend is deactivated
AND i'd like to add something: stagger the cylinders at 90 degrees, so that you get more steady power.

If you still don't know what "gun tech" is, i'll upload a demo

Thank you again. I changed my motor, I changed the ratio (I think), I put the gun tech (looking at the vaidas369 motor).

If I changed polygon in a simple box, does it will work?

About the bend, I will try different value and try to find some tuto.

About the 90degres piston You have right. I made this beacause actual 4 cylinder works like this but I forgot they are 4 stroke and not 2 stroke.