Says who? No-one knows exactly what the c/r is apart from the engine builder, just because someone "claims" high comp, how do you know they aren't leading you up the garden path with disinformation? .

There goes loads of people building high comp engines and blowing them to pieces and the person who started the high comp rumour can have a laugh at your expense, as you try and achieve what he has gained from proper experience and end up getting nowhere .