I showed it to Peter today at Skater. He had me send it to his brother in Canada who is an outboard guru and works on F1 boat engines. He told me he would call them and let me know what he finds out.
He did say it was possible. He has friends who "use the 4 cylinder Honda engine, put immensely thick steel sleeves in it, turbo-compound it (two immense turbos, one feeding into another using insane octane fuel), and making 1500hp. But for 10 seconds max!"
I'll let you know what he finds out.