ok i dont know if i figured it out right but i got some plexiglass with a hole in it and some grease. i stuck the plexiglass to the head with grease and filled up the chamber with water out of a syringe. the head held 54cc of water i tried 2 times in two diffrent chambers and they both held 54cc. is that the right way to do it??? using 54cc here is what i get

Bore Size: 4.03"
Piston Size: 4.027"
Stroke: 3.75"
Deck Height: 0.005"
Piston Ring Land: 0.25"
Piston Dome/Dish: 5 cc
Head Gasket Bore: 4.125"
Head Gasket Height: 0.039"
Cylinder Head Volume: 54 cc
Cylinder Volume: 783.826 cc
Gasket Volume: 8.541 cc
Deck Volume: 1.045 cc
Total Volume: 852.49 cc
Engine Displacement: 382.66 cid
Compression Ratio: 12.42:1

I hope I can run this motor off of 92 octane. BTW I am using a hotcam (emissions). please I dont want to hear how this is to small of a cam i allready know and dont care.

 

Yep that looks right man...keep in mind...if you mill .006 off your heads to 'clean them up', you will drop 1cc off your combustion chambers.

Also, when you say deck height of .005, do you mean .005 above or below the top of the block? If you want to mean ABOVE, you have to enter it in as -.005 in the calcs.

I ran into the same problem...check out this thread here for some great info:
http://web.camaross.com/forums/showt...postid=1010579

What I did to correct it was have my builder keep the 5cc valve reliefed flat tops and get me some 16cc inverse dome pistons.

My math comes out to this:
Bore: 4.030
Stroke: 3.75
Conn Rod Length: 6
Cyl Head Vol: 53 (Was 54, now 53 due to milling the heads .006)
Deck Height: -.005 (5 out of the hole)
Head Gasket Bore: 4.125
Head Gasket Thickness: .039
Piston-Wall Clearance: .003 (SRP specs .0025-.0035)
Top Ring Land Height: .25 (What was in the calc, shouldn't make a diff)
Dish Volume: 16cc (Inverted Dome)
Compression Ratio: 11.24:1

 

no mine is .005 in the hole. Dave88LX why does it need your rod length? what does that have to do with compression ratio

willl mine run on pump with 12.42:1 ratio

 

OK just checking. I'm not sure why it asks for the rod length It didn't make a difference in the equation...

I used this calc here:
http://www.smokemup.com/auto_math/compression_ratio.php

I can't comment on if it will run on that CR or not...check out that thread I linked to...some are running pretty high, but I know personally I wouldn't feel comfortable running that high of a CR...not on pump gas. Hell the ford guys I talked to thought I was a little nutty for considering 10.5:1 until they learned that I had aluminum heads and reverse coolant flow...