I'm sure that many of ya'll will get a good laugh here, but I am trying to determine the compression ratio of my engine. I am using one of those auto-calculate programs, and I have tried to search and find the correct measurements to fill in the chart. Well, according to their chart, my compression ratio is 1.3523 to 1 Now, I just have a feeling that due to some mistake of mine, that this is just a little bit off. Can ya'll help me out? Here are the values that I entered in. Number of cylinders 8 bore 4.044 stroke 3.0028 Capacity 308.5521 cubic inches Combustion chamber volume 54 Piston dome relief -5 Deck height 8.2 Head gasket bore 4.1 Compressed thickness .042 Gasket volume CC 9.085 Piston diameter 4.0385 Depth to top ring ? Remember, I am not looking for my exact CR, just a ballpark. I have a 302 punched out 40, flattop aluminum pistons( ? brand ), stock 1980 heads (ported, polished, shaved) Does this help ya'll figure out what I did wrong? (Or is it so obvious that you are rolling on the floor laughing?) I am just curious here. Help me if you can please, Thanks a bunch, Country
I cam up with 10.28 To be more accurate I need to know 1)how much is the piston down below the deck @ TDC. I used 0 inches. 2) the volume above the piston to the top of the deck @ TDC. I used 5 cc's here This is using desktop dyno so I dont know how accurate it is Chad
You should be about about 10 1/4 I just depends on where your pistons are at TDC...if they are above, even or below the block. if they are below the deck surface at all use a thinner head gasket for proper quench....well I would
Thank ya'll very much! Thank you both very much. I had no clue what was wrong. I really appreciate you taking the time to help me. Thanks......Country
