GCR Compression Ratio Definition and Calculation
#30752 from Club Racing Board · Rule change · TB 21-07 (2021-07 Fastrack)
In GCR Appendix G, Section 1., add the following:
"Compression ratio = V1 + V2
V2
Where V1 is total volume of one cylinder: sum of swept plus unswept volumes.
V2 is enclosed volume existing in a cylinder/cylinder head with the piston at its closest approach to the cylinder head."