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1972_911T 1972_911T is offline
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Join Date: Jul 2005
Location: Yorkshire UK
Posts: 1,097
Stock 72t Compression Values

What sort of compression value would you expect to get from a stock 911 t with 7.5 ratio?

If I remember back to my physics lessons atmospheric preassure is 1 bar/ atmosphere at sea level! Therefore a compression ratio of 7.5:1 should give a value of around 7 bar if the engine is in good health of cause. As you are increasing atmospheric pressure by a factor of 7.5

Please feel free to correct me if my assumptions are wrong!

I have just compression tested my engine and it gave values of between 11.2 - 11.8 bar this seems high for a stock 911t. Could it be that my engine is not stock as far as compression goes or am I way out with my assumptions and these figures are what you would expect from a 911 t with 7.5:1 compression ratio?

Old 07-30-2005, 07:43 AM
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