# Compression Ratio Question



## 67lemans (Oct 30, 2009)

I disassembled my 326 today and cc'd the 140 heads. They all come in at 66/67 which seemed small to me so I assume maybe they were milled at some point. The pistons are the double eyebrow type as pictured. With a standard head gasket, what would you guess the compression ratio to be? It is bored .030 over. Thanks.


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## Montreux (Mar 8, 2009)

67lemans said:


> I disassembled my 326 today and cc'd the 140 heads. They all come in at 66/67 which seemed small to me so I assume maybe they were milled at some point. The pistons are the double eyebrow type as pictured. With a standard head gasket, what would you guess the compression ratio to be? It is bored .030 over. Thanks.
> View attachment 135009


Wallaceracing.com has a compression ratio calculator.


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## 67lemans (Oct 30, 2009)

Thanks Montreux. I had accidentally sent this question twice. And some others had answered it on another thread. But I appreciate you replying.


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