Plan for the day is to define the Cam box end plate, cambox cover and the cambox top features. These include the bearing surface for the cam and a way to collect oil used to lubricate the cam and pass it down to the cylinder head. The cambox end plate may seem like an odd place to start, but this plate will blend with the cambox and the cambox cover and define the shape of the cover and how it blends into the cambox.
Looking at the picture above and below, it can be seen that the cam box cover blends very nicely (tangent entry) with the cambox.
Below is my first attempt at the cover and end plate. I did not understand the relationship of the shapes yet and the cover and cambox do not blend well.
The issue seemed to be whether area between the cam box side and the curvature of the cover was vertical, or parallel with the cambox.
So I loaded a picture of the cam box end plate into my cad software and overlaid a couple of circles and a tangent line between them. Then I dimensioned the drawing and generated ratios I could use to define the shapes. Using this I create a new cam box end plate 3d model.
Below is the resulting 3d model, I am much happier with this look than my first attempt.
Below is a cut away of the cambox and cover showing the way they are joined.
Next I simply transfer the features on the head where it mounts to the cambox over to the cambox bottom as shown below. These features include the large holes that support the cam followers and the small mounting holes. FYI, the cam follower is a part that rides on top of the valve and provides a larger surface area for the cam to work against. It is really just and inverted cup with the valve stem sticking up into the end and the cam riding against the outside.
Then I add the features to the top of the cambox: the oil troughs to collect the oil used to lubricate the cam and the holes to let the oil drain down to the head.
The troughs are cut with a ball end mill, giving them a rounded, funnel shape.
This is where I finished today, I still have some work to do at the interface between the gear tower and the cambox. This area is shown by the red circle and you can see the current interference area.
Next I’ll work on the camshaft, then refine the interface between the cambox and the gear tower.