Compression ratio

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Mar 30, 2003 | 01:24 AM

lifeworks@dmv

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Compression ratio

Just purchased a 1993 F-150 w/<a href="http://www.motorhaven.com/">302 </a>short block. What is the compression ratio required?
May have to replace engine due to bad #7 cylinder.

Mar 30, 2003 | 08:50 AM

mantta

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From: Keweenaw Bay, MI

Compression ratio

I think you mean, how much compression pressure should you have. The answer is that the lowest pressure you get must be at least 75% of the highest reading you get to be acceptable. This is from the Ford F Series Specifications Book. Other manuals will say if it is 20% below the pressure of the other cylinders.

Mar 30, 2003 | 08:10 PM

mrak

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Compression ratio

Just turning over the engine cold, with out opening up the throttle and things needed for a proper compression check I was getting in the 120-150 lb range on my 1994 with 105k miles.