I'm not arguing with that, but would be grateful,as a non engineer, for more information.
As I said in an earlier post, The early MV. 160 glows had the same needle-roller conrod(big and little ends) as the petrol version.
I tried one for f3a use(Piped and pumped, APC 16/14or 17/12 from memory)
The big end failed(cage distorted,again from memory-I think that was what it was) twice in short order.
It's run OK ever since, with the factory replacement bronze bushed conrod.
It seemed that the needle-roller bearing couldn't withstand the mechanical forces from the "big glow bang".
So, why is the needle roller bearing necessary for petrol?