I am now satisfied with the improvments made on this engine. Very low idling, good transition between the different rpms, cylinder temperatures quite similar.
The engine is equipped with standard exhaust pipes on the test bench, but will be used with a keleo exhaust on the plane (Beaver H9)
As already stated, the most effective modifications have been the passage of gases through the crankcase (modification made by myself) with a reduction of the operating temperature especially of the cylinder 1, and the MMM timing ring - very smooth running, and very good transition between the different rpms. The engine runs well between 900 and 7000rpm
A short video
Note: I am also happy, because I am finally allowed to publish links
JM