That article was also published in SAE Journal without the ads in the second part
Some Notes on Design Features of The Mitsubishi Kinsei Engine - W. G. Ovens SAE Transactions, Vol. 50 (1942), pp. 253-266 - ID:44439189
That is on AEHS https://www.enginehistory.org/Piston/Japanese/KINSEI.pdf with text but worse image quality.