CAMARO6 - View Single Post - PRAY Ported LT1 Heads preliminary results

PRAY · 02-22-2017, 08:51 PM

I hardly ever increase cross section either horizontal or vertical if the head is not going on a larger motor. 99% of the time I only remove material from the short turn, hook wall, rocker boss, and valve guide area. I will make slight adjustments to the chamber as needed around the valve seat. All I did in this head was remove the obstructions in the intake port and reshape the short turn a bit. There really isn't much material around this port to take much out. Considering this is a dry head and I am only moving air I wasn't concerned with having to move fuel with it. Since it is DI as well and the fuel is coming out of the injector basically atomized I was more concerned with swirl. It is just a little difficult with this head since the runner is "backwards" and there isn't much material available to remove on the hook wall or short turn on that side. In the end, I didn't really change what GM did. I just removed some of the restrictions and cleaned things up. I also wanted to keep the port from crashing at .550. I didn't see it on my bench due to only being able to reach 7" stock and 5" ported. But I have done enough heads now to know what my short turns need to look like to stop flow seperation of the short side at 28". On the next port I may leave the entire bump around the push rod in and see what is does to port velocity on the hook wall side over the short turn. Kind of use it as a swirl generator and get the air off the straight wall. On the exhaust most of the gains were made in the valve seat and bowl area. But that is the evacuation side so not so critical. I just wanted a certain amount of volume. I did what was needed to get the numbers I was looking for.

02-22-2017, 08:51 PM	#5
PRAY Drives: 2016 2SS Join Date: Jul 2016 Location: Sanford NC Posts: 2,766	I hardly ever increase cross section either horizontal or vertical if the head is not going on a larger motor. 99% of the time I only remove material from the short turn, hook wall, rocker boss, and valve guide area. I will make slight adjustments to the chamber as needed around the valve seat. All I did in this head was remove the obstructions in the intake port and reshape the short turn a bit. There really isn't much material around this port to take much out. Considering this is a dry head and I am only moving air I wasn't concerned with having to move fuel with it. Since it is DI as well and the fuel is coming out of the injector basically atomized I was more concerned with swirl. It is just a little difficult with this head since the runner is "backwards" and there isn't much material available to remove on the hook wall or short turn on that side. In the end, I didn't really change what GM did. I just removed some of the restrictions and cleaned things up. I also wanted to keep the port from crashing at .550. I didn't see it on my bench due to only being able to reach 7" stock and 5" ported. But I have done enough heads now to know what my short turns need to look like to stop flow seperation of the short side at 28". On the next port I may leave the entire bump around the push rod in and see what is does to port velocity on the hook wall side over the short turn. Kind of use it as a swirl generator and get the air off the straight wall. On the exhaust most of the gains were made in the valve seat and bowl area. But that is the evacuation side so not so critical. I just wanted a certain amount of volume. I did what was needed to get the numbers I was looking for. __________________ 2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.