> I must be missing something, or receiving something different to what
> I'm expecting - or more probably the data I have is not correct for the
> calculation.
>
> Bore: 3.16"
> Stroke: 3.5"
>
> >From that I calced Swept Volume to be: 449.82 cc's.
> Combustion Chamber Volume: 42.5cc
>
> SV + CCV / CCV = 11.58 CR
>
> Ok, what am I doing wrong? My spreadsheet I did up works from the test
> data in this blueprinting book I have. Is there something different
> about the data I'm supplying? I guess there must be.. I've ordered a
> real auto math book that I guess will answer this, but somebody want to
> explain anyways? :)) Is this a GCR vs CR thing? I have no idea what the
> difference is at this point!?! <G>
Neil, how are you measuring your combustion chamber volume? You need to
have pistons and rods and crank in situ when you measure this, since
deck height affects the combustion chamber size. How are you measuring
the volumes? You need a large graduated syringe, or other suitable
item, like burette. Do you know if your heads have been resurfaced or
the block has been decked? If so, this can raise the compression quite
a bit, but I think 11.58 is a bit high. Your piston dish is also
important. This should be taken into account when you are calculating
the combustion chamber volume. I can't comment on your volumes you have
there, although I suppose CCV should be larger. Remember that deck
height affects combustion chamber and will increase CCV.
Please detail your procedure.
Take care
Jay
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