Compression Ratio?

[69chargerdad]

Hi were back again. Can anyone tell us what compression ratio we are running in our 440 or the proper equation? The 440 is 30 over so it now has a 4.350" bore with the stock 3.75" stroke. The heads are 906 open chambered that are cc'd at 93. The block is zero decked with diamond flat top pistons.

          Thanks Ken and Marcus

[Runner]

heres a calculator for you guys.      i came up with a 9.544  but i assumed a 5 cc valve relieve, a TRUE 0 deck, a 4.50 bore gasket (like the felrp 8519pt) and a .039 gasket thickness.    those heads have some large chambers!!

http://kb-silvolite.com/calc.php?action=comp

[69chargerdad]

    thanks runner  i'm looking it up now         Ken

[cudaken]

 Was there work done in the chambers? Most stock 906's should come in around 88cc's.

                                Cuda Ken

[firefighter3931]

If you need more static compression there's allways the steel shim head gasket option. Using the same parameters that Runner used it works out to 9.96:1 with the .020 steel shim gasket.  

Ron

[69chargerdad]

   thanks guys   the chambers were polished and we deshroulded the valves    2 came in at 92      6 at 93    we're thinking about the head gasket option now instead of milling the heads.    ken

[cudaken]

 I use the steel shim's my self when there not a blower going on.

                                        Cuda Ken

[Chryco Psycho]

steel shims work great & are cheap too