New block, a further discussion

[Ol' Ron]

In the combustion chamber there is an area known as the " transfer area" This area can be considered as part of the ports. It has an angle in which air/fuel enters the cylinder. The angle, shape and length along with the exit angle determines the CR as well as the flow cheristics of the head. By changing these dimensions and angles, you change the CR and air flow. The "Denver and most aftermarket heads just reduce the angle which raises CR but limits flow. When I was making flow tests I found that an 11/12 degree angle was best and is what most stock heads have. However the exit angle is pretty sharp and increasing it to 60 degs flow improves, Unfortunately this reduces the CR. As for the spark plug location. I would suggest that placing it in the transfer area and at the same angle would improve combustion and low the Octane number of the chamber.
AS you can see this is a complicated issue involving many things. I have some flow data in my book. However it in percentages as I couldnot get accurate CFM
Good luck Plese excuse the spelling

[aonemarine]

Originally Posted by Ol' Ron

In the combustion chamber there is an area known as the " transfer area" This area can be considered as part of the ports. It has an angle in which air/fuel enters the cylinder. The angle, shape and length along with the exit angle determines the CR as well as the flow cheristics of the head. By changing these dimensions and angles, you change the CR and air flow. The "Denver and most aftermarket heads just reduce the angle which raises CR but limits flow. When I was making flow tests I found that an 11/12 degree angle was best and is what most stock heads have. However the exit angle is pretty sharp and increasing it to 60 degs flow improves, Unfortunately this reduces the CR. As for the spark plug location. I would suggest that placing it in the transfer area and at the same angle would improve combustion and low the Octane number of the chamber.
AS you can see this is a complicated issue involving many things. I have some flow data in my book. However it in percentages as I couldnot get accurate CFM
Good luck Plese excuse the spelling

love to see some pictures of the combustion chambers if you have them....