Intake port, race port?

[911st]

Dose anyone know what is going on with this porting job?

Thx

[JFairman]

Looks like it's been opened up to 40mm and probably a little bigger and material has been removed around the valve guide and the roof of the port to help streamline airflow around the valveguide and lift the air flow a little to increase the ports flow rate, and the valve guide has been tapered down to make it thinner at the end also to remove some airflow restriction.
Doing that to the valve guide also removes some of it's heat transfer ability in that area of the valve stem..
The inside walls have been smoothed out and blended nicely.

It sort of looks sort of like the short side radius has had aluminum welded in and has been recontoured with a taller short side radius.
But, that may be an optical illusion from the 2 dimensional picture and the angle light is hitting the inside of the port from above.

Raising the sort side radius could help straighten out the airflow more evenly before hitting the backside of the intake valve but you'd need to test it on a flowbench to know if it makes the port flow air better at certain velocities.
Kind of like having higher, straighter port angles to make the airflow hit the back of the valve at a straighter angle for better high rpm breathing but not really because the air flow still has to bend and turn almost 90 degrees before hitting the back of the intake valve.

[911st]

It sure it pretty.

To my eye it looks like there is a crescent-shape- step built into the area across from the injector relief.

Is that the case or is it just the angle of the photo and of lighting?

Thx.

[xtremech]

From what I can see, someone took great care to provide a quality job. A picture probably wont show enough to get quality feedback. I suggest having it flow tested.
What is the valve size?
What is the port size?
What is the radius on the backside of the valve? (It looks like maybe 12degX.500)
I may be able to provide some numbers that it should flow if it was done properly.
Very nice looking product.

[911st]

Bill,

Not my head. Saw it in a post and it looked like to me like it had step built into it but it must be the picture.

Thank you.

[xtremech]

It looks like one of two things....
I think that it is an angle leading into the port.Looks like the factory machining because of the color of the cut (it has been glass beaded).
Or, the machinist put it there to accomodate a larger intake manifold combination.
Should be blended though.