Originally Posted by Quarter Flash
Thank you for that information. If anyone knows what ratio I am starting out with for sure it would also be helpful
actual vs "advertised" compression can vary quite a bit for older cars. just meausre your piston volume, deck clearance, gasket thickness, and head volume and calculate your own compression.
If you don't have a mic you can measure your volume above the piston by bringing it to TDC and sealing the edges with a thin layer of petroleum jelly. Use a common medical syringe to measure the volume- available at any corner drug store.
be sure to have it level and seal the top with either a hard plastic sheet or an old CD.
These are common cheap tricks that most of us use around here.