# Cylinder head design



## mad_mat222 (May 11, 2021)

Squish v compression

Im working on a 322l trimmer https://www.arboristsite.com/community/threads/mod-husqvarn-322l-xtorq-trimmer.351488/ as well as the ms180. Both have similar combustion chambers. 

the combustion chamber is dead flat with the exception of the spark plug hole which got me thing about squish bands and combustion chambers. Effectively the squish band on the trimmer is 10mm thick and the combustion chamber 10mm in diameter. Has any comparisons been done with squish band width eg if the squish band was reduced to 5mm and then add a pop up piston to fill the additional volume created in the combustion chamber?

Is there a direct relationship between narrow or wide squish bands v how much compression. The ms180 is the same and is the next project aka ms180 hotsaw. Lower compression, cheap mass produced pistons seem to have flatter areas at the top of the cylinder where as higher compression ms660 have the nice dome combustion chamber.

Any thoughts on these observations?


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## mad_mat222 (May 13, 2021)

What is squish ratio


title says it all What is squish ratio mean



www.x-h2o.com





That is interesting reading


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