Choosing the right stroke for a 340
Eliminating Cylinder Head Valve Shrouding for Improved Performance - Part 9
Look at valve on right in the picture below. And treat that moved out right side line as cylinder wall. That moved out line is a bigger cylinder bore.
A 318 has a 3.91” bore originally, and 360 has a 4.00” bore and your 340 block has a 4.04” bore.
the bigger the bore, the less red area shown below:
Below: Fig. 9.10. Air does not enter the cylinder evenly all around the intake valve. Here, better than 60 percent enters via the valve’s “A” half. This means the “B” half is in less need of de-shrouding. Note: the flow exiting the valve is turning, thus generating swirl.
Below: Fig. 9.8. A hemi-style cylinder head has zero valve shrouding. This comes about because as the valve opens, the distance from the edge of the valve to the cylinder wall increases from A to B.
Eliminating Cylinder Head Valve Shrouding for Improved Performance - Part 9
Look at valve on right in the picture below. And treat that moved out right side line as cylinder wall. That moved out line is a bigger cylinder bore.
A 318 has a 3.91” bore originally, and 360 has a 4.00” bore and your 340 block has a 4.04” bore.
the bigger the bore, the less red area shown below:
Below: Fig. 9.10. Air does not enter the cylinder evenly all around the intake valve. Here, better than 60 percent enters via the valve’s “A” half. This means the “B” half is in less need of de-shrouding. Note: the flow exiting the valve is turning, thus generating swirl.
Below: Fig. 9.8. A hemi-style cylinder head has zero valve shrouding. This comes about because as the valve opens, the distance from the edge of the valve to the cylinder wall increases from A to B.