rwilles
Registered User
Combustion chamber volume Fair warning: Math ahead
The math for the combustion chamber has been bugging me all day. Somebody check both the thought process and the math so we can come up with good numbers.
We are starting with a 7.3l, 444 cubic inch motor. Divide by 8 to determine starting volume for one cylinder, equals 55.5 inches^3.
-Divide volume by the compression ratio of 21.5 and the volume of the combustion chamber is 2.58 inches^3.
-Area of a circle is PiR^2. Bore diameter is 4.11 inches, Radius is 1/2 or 2.055. Area of the Bore is 2.055. *2.055*3.14156= 13.26 in^2.
-Area of the combustion chamber is 2.58 in^3 so chamber / by bore = approx thickness in inches between head and piston top. 2.58/13.26=.1945 or about 195 thousandths.
-Gasket material makes up .030-.040, so without gasket we have .1545 thickness. A gasket with a .05 thickness would increase height to .2045 and the chamber to 2.712 inches^3. Divide that number into the original volume of the cylinder 55.5/2.712=20.46 compression.
-A .075 gasket to yield a combustion chamber of 3.284 in^3. 55.5/3.284 = 16.9 compression.
Room to deck the heads and still drop the combustion pressures at .075 thickness. Perfect for a .075 Garloc Helicoflex (someone else calls it Phew..., as in RnD fees really stinks up the place!) fire ring.
I think based on the Hypermax and VR designs with Carbon fiber, A carbon fiber gasket that compresses to .075 (starts at .125) if we can pair that with a .075 Garlock fire ring , the whole shebang would allow for old and new engines to get the upgrade and lower the compression. Seems like a win-win for all of us.
The math for the combustion chamber has been bugging me all day. Somebody check both the thought process and the math so we can come up with good numbers.We are starting with a 7.3l, 444 cubic inch motor. Divide by 8 to determine starting volume for one cylinder, equals 55.5 inches^3.
-Divide volume by the compression ratio of 21.5 and the volume of the combustion chamber is 2.58 inches^3.
-Area of a circle is PiR^2. Bore diameter is 4.11 inches, Radius is 1/2 or 2.055. Area of the Bore is 2.055. *2.055*3.14156= 13.26 in^2.
-Area of the combustion chamber is 2.58 in^3 so chamber / by bore = approx thickness in inches between head and piston top. 2.58/13.26=.1945 or about 195 thousandths.
-Gasket material makes up .030-.040, so without gasket we have .1545 thickness. A gasket with a .05 thickness would increase height to .2045 and the chamber to 2.712 inches^3. Divide that number into the original volume of the cylinder 55.5/2.712=20.46 compression.
-A .075 gasket to yield a combustion chamber of 3.284 in^3. 55.5/3.284 = 16.9 compression.
Room to deck the heads and still drop the combustion pressures at .075 thickness. Perfect for a .075 Garloc Helicoflex (someone else calls it Phew..., as in RnD fees really stinks up the place!) fire ring. I think based on the Hypermax and VR designs with Carbon fiber, A carbon fiber gasket that compresses to .075 (starts at .125) if we can pair that with a .075 Garlock fire ring , the whole shebang would allow for old and new engines to get the upgrade and lower the compression. Seems like a win-win for all of us.
