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BK911 BK911 is offline
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Join Date: Mar 2001
Location: Rocky Top, TN
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Compression ratio is sort of a misnomer. Its a volume ratio, not a pressure ratio. So 7.5:1 means the volume decreases by 7.5 Xs, not that the pressure increases by 7.5 Xs. The latter would have been correct if the air/fuel mixture stayed the same temperature throughout the compression process. But since the temperature increases during the compression process, it raises the resulting pressure.
'71 911E Targa rustbucket
Old 07-31-2005, 10:09 AM
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