Originally Posted by 2fast9tech2 (Post 3500076)

that doesnt make sense. these boat engines are not much different from car engines. if you go buy a car with a 9.5:1 ratio it will recommend 87 or 89. in my lexus with a compression ratio of 11:1 they recommend 93. it all has to do with timing.

this is straight from wikipedia (it all relates to burn rates of octanes, the higher octanes burn longer thus they burn for the entirety of the stroke vs a smaller compression ratio needs an octane that burns quicker):


Picture a cylinder and its combustion chamber with the piston at the bottom of its stroke containing 1000 cc of air (900 cc in the cylinder plus 100 cc in the combustion chamber). When the piston has moved up to the top of its stroke inside the cylinder, and the remaining volume inside the head or combustion chamber has been reduced to 100 cc, then the compression ratio would be proportionally described as 1000:100, or with fractional reduction, a 10:1 compression ratio.

Originally Posted by jeff1000man (Post 3501861)

The attention Getter was re introduce to the Atlantic ocean today. She definitely like it.

Thanks Joohn for showing me around and recomending the marina. The folks over there have been great so far.