[Henry Floored]

Guys I don't think exhaust porting on the Flathead Ford is that big of a problem.

When that piston goes up on the exhaust stroke it's gonna slam the spent gases outta the cylinder. I concentrate on the end exhaust port entrances and exits. Those four locations are where you find sharp turns and flow limiting passage sizes.

In the center there is plenty if not too much exhaust port volume. The problem there is no structure to direct flow out the exhaust port. The heat riser should be filled to a point where it forms a curved back wall in the valve pocket area. A little thin tongue extending into the entrance of the center port would be icing on the cake.


In a non- compound actuated valve in block V engine like the Flathead Ford, (an example of a compound actuated valve in block V engine would be a Lycoming/Cord V8) the limit to airflow is all intake. A lot more intake flow has to occur, in my opinion, before we over tax the exhaust side.

To dramatically improve airflow in a conventional valve in block engine the entrance to the valve pocket or at least the shape of the port leading to the valve pocket could use a lot of improvement. The removal of abrupt changes of direction in the intake path is the first step to greater volumetric efficiency.

The next step and just as important is the relationship in valve to piston location. In the stock configuration we are almost literally asking the intake charge to "bounce" or at least deflect off an iron wall then head down into the cylinder.

If we want to move Flathead Ford airflow to the point where wholesale changes to exhaust porting become necessary I believe the stuff I mentioned need to be revisited.