Riser B

Design B -- Center pour cavity

The hub and fork sections on the two ends of the snubber arm are not major thermal masses, because of their large center bores.

Solidification will naturally start at those two ends and then progress inwards to the center of the heavy bar section.

The diameter of the center pour cavity can be expanded to act as a riser that feeds into the heavy bar section and promotes the natural directional solidification.

The pour cavity is 10" in diameter and 10" high.

Solidification modeling confirmed that a center riser gave the the best solidification.
(A video (Avi file) of a filling and cooling model for the snubber arm casting).

A center riser/ pour cavity is best location for producing directional solidification.
Go on to the next design issue.