On Saturday, July 8, 2017 at 6:23:42 AM UTC-5, Werner Schmidt wrote:
Hello Ueda

you also may consider a complete different engine. Our club in northern
Germany uses a tost winch, too and in the 1980ies fitted a Mercedes Benz
330 HP Turbo-Diesel truck engine which works fine up to now. No Gearbox
required, just the torque converter between engine and drive shaft. You
may have to change the gear transmission ratio to adapt it to the
different revolution speed range and do some more minor changes. I could
help with construction schemes - hope I have found the correct terms, my
english is somewhat poor :-/

regards

Werner

Werner,
We got a similar (identical?) Benz Diesel in the mid-80's together with a modified axle from their test shop for free (Luftsportverein Hameln/Bisperode). The engine and axle still are still in great shape. Not an option for us here in the US and for sure not in Japan.
Herbert, J7