Never groove the journal, or drill a #%?!ing hole through your crank. It is not the solution. I think this is the only forum not dedicated to pre-war Bentley’s that still discusses it.
https://www.mahle-aftermarket.com/media/local-media-north-america/pdfs-&-thumbnails/support_technical_bulletins_pdfs/tb2051.pdf
On a more pleasant note, behold the incredible hollow crankshaft!
http://www.f1-forecast.com/pdf/F1-Files/Honda/F1-SP2_08e.pdf