Intake ports/velocity/temp?

[JimV]

When high pressure moves to low pressure the air is cooled ie. remove the valve from a tire and the tip of the valve stem frost up or in a carb the boosters will frost in the low pressure area.

question: By Increasing velocity in an intake port is there an advantage by the cooling effect?

[Darin Morgan]

When high pressure moves to low pressure the air is cooled ie. remove the valve from a tire and the tip of the valve stem frost up or in a carb the boosters will frost in the low pressure area.

question: By Increasing velocity in an intake port is there an advantage by the cooling effect?

If the charge is cooler, the density of that charge is higher thereby increasing the inertia and ram effects BUT the rate of vaporization of the fuel suffers in the process. Does cooling help? Yes it does, to an extent, BUT you would not want to increase the velocity simply FOR the cooling effect because that's looking down a rabbit hole that goes no where. If you increase the velocity in order to cool the charge you use up energy to do so. You cant use the energy of the mass flow in order to induce swirl, cool the charge, turn the air or do anything else except get it into the cylinder. Any amount of energy you use in the manipulation of the charge is just that much less you get into the cylinder.

Bottom line, Its the wrong way to cool the charge.

Side note, A venturi is designed to accelerate the air to a given velocity over a very short span and recover the energy at a given rate so as to not waste or use as little of the energy at hand to accomplish the task. Pressure recovery dynamics in the divergent region of the venturi are critical to the amount of air that can pass through it. That's why the bowl, throat, seat and chamber are so critical in a cylinder head. The bowl is the high pressure ( convergent ) region of the venturi and the throat is the venturi itself while the chamber acts like the ( divergent ) region to recover the energy.

I sure hope this sparks some of my fellow head nuts to give us there insight into this. I think its a very good question we could all learn from.

[mike_belben]

That's why the bowl, throat, seat and chamber are so critical in a cylinder head. The bowl is the high pressure ( convergent ) region of the venturi and the throat is the venturi itself while the chamber acts like the ( divergent ) region to recover the energy.

ive been reading as much as i could find about cylinder heads, porting, fluid dynamics and critical flow venturies for about 2 years now. in 2 minutes this paragraph has given me more depth of understanding than everything else. like someone just took the blindfold off and tied it all together. i hope this thread explodes. thank you.