Care to enlighten me? I based the compression ratios on what I was able to find in the repair manuals...
As I said, the values are approximations. I quickly ran this through a calulator and ended up with some lower values, but still somewhere around 11:1 mark for the 750 heads.
I used this one
http://www.csgnetwork.com/compcalc.htmlEnter Cylinder Bore Size 95
Enter Piston Stroke Length 75
Enter Head Gasket Bore Diameter 98
Enter Compressed Head Gasket Thickness 0.75
Enter Combustion Chamber Volume In CCs 47
Enter Piston Dome Volume In CCs Negative For Dished Pistons (Use '-') 0
Enter Piston Deck Clearance Negative If ABOVE Deck (Use '-') : 0
and it cam back with 11.09:1
I admit I haven't (yet) measured the exact combustion chamber volume of my 750 heads, but I think I am not that far off with the factory's claim of 47cc. The biggest question to me is the thickness of headgasket on an 1100 cylinder as that could easily be twice the thickness and I wouldn't know it... dropping compression to around 10.1:1 straight away.