Algodoo

Better than most people's attempts...
I'm getting tired of writing this on every scene but here you go:

First of all, use realistic size. At least make it less than 1 meter high please!
After that you'll notice that physics are really clunky, and objects go through one another, and axles sretch... there are 2 solutions to this:
First and foremost, DENSITY. Use high density for EVERYTHING. High density is more than 50. It doesn't matter if the engine weights too much after that, although you can start cutting up density on non-colliding objects for example, to cut some weight.

And last is FREQUENCY... this one is the most useful, but it also gives a ton of lag. Use less than 240 Hz if you can. The best is 120 for engines, though guns need more than 120 usually. Frequency is under Settings - Simulation (there's a slider)

Thank you for those useful tips, linkage, that was exactly my problem. I am sorry if it was/is tiring you, but it is those comments which help making things better. It war pretty hard to do, and it still is nor really good, but after 2 hours of trying, i was happy to have a result at all. i was too tired to improve it. But again, thank you, i really have an use for those comments. Do not worry, i am not stupid, i was just to tired. Well, i just lied, usually i am stupid.

the engine bounces around when at high RPM