Bluezone
Tailgaters will be prosecuted.
I watch these two videos on Port flow. It gave me some interesting ideas to try out on the intake manifold and possibly the ports. I've included my observations in my reply to the second video.
"I think you're onto something there with what you're describing regarding the gathering of the dykem towards the centre cylinder head. But there's a secondary effect going on as well for what I can see. So, there's also a direction, vector change, and velocity change. The dimples are increasing the velocity of the air near the wall surface. So, the major airflow is closer to the surface of the portwall. The fallout, literally, is the heavier particles of the dykem maintaining their velocity vector in the changing direction of the airstream. So, the dykem is separating out of the airstream because of the directional change of the air. This is over a wider dimpled area. On the plus side, this high-flow area is contributing to increased overall portflow by reduceing velocity loss through this high flow area.
In the stock intake, airflow is farther away from the port wall. So it's performing a gentler turn into and through the port wall radius and valve seat aperture. This would be a great modification for direct injection but poor for port injection or carburetion. Obviously, you want the fuel to flow into the cylinder with the air.
The dimpled Port also demonstrated that the airflow was clinging to the port wall even around the radius headed into the valve.
While the non dimpled Port reveals the change in Port profile via the smaller dykem deposit, showing the gentler change of direction.
Low-flow, low velocity, turbulent areas should benefit from dimpling. Meaning this could help with directing airflow. So the backside of the valve guide and the tight radius into the the short side could see improved air distribution with dimpling.
Also keep in mind the Bernoulli effect. High Velocity through restriction equals low pressure. Pressure moves from high to low."
What does everyone else think?
"I think you're onto something there with what you're describing regarding the gathering of the dykem towards the centre cylinder head. But there's a secondary effect going on as well for what I can see. So, there's also a direction, vector change, and velocity change. The dimples are increasing the velocity of the air near the wall surface. So, the major airflow is closer to the surface of the portwall. The fallout, literally, is the heavier particles of the dykem maintaining their velocity vector in the changing direction of the airstream. So, the dykem is separating out of the airstream because of the directional change of the air. This is over a wider dimpled area. On the plus side, this high-flow area is contributing to increased overall portflow by reduceing velocity loss through this high flow area.
In the stock intake, airflow is farther away from the port wall. So it's performing a gentler turn into and through the port wall radius and valve seat aperture. This would be a great modification for direct injection but poor for port injection or carburetion. Obviously, you want the fuel to flow into the cylinder with the air.
The dimpled Port also demonstrated that the airflow was clinging to the port wall even around the radius headed into the valve.
While the non dimpled Port reveals the change in Port profile via the smaller dykem deposit, showing the gentler change of direction.
Low-flow, low velocity, turbulent areas should benefit from dimpling. Meaning this could help with directing airflow. So the backside of the valve guide and the tight radius into the the short side could see improved air distribution with dimpling.
Also keep in mind the Bernoulli effect. High Velocity through restriction equals low pressure. Pressure moves from high to low."
What does everyone else think?