Stirling engine with rhombic drive

Stirling engine with rhombic drive at the beginning of development
Swept Volume 75 ccm
Max free speed till now 1600 rpm
Max performace till now 12 Watts measured with a simple prony brake
Completely dry-running
Unpressurized till now but prepared for pressurization up to 10 bar

I know 12 Watts is ridiculously low for such a big engine but it
is still just the sturdy base for forecoming improvements
Its much fun to see the engine developing and the fact that
minor changes sometimes dramatically change performance
is very encouraging
Although it is much more work then it seems
e.g. about 20 sets of piston rings (10 rings per set !) were manufactured
and tried till now and compression is still not really satisfying

Thanks for watching and I am always happy for comments and suggestions

tom-rock