ABSTRACT: The transformation from the liquid to the solid state is accompanied by the volumetric shrinkage that occurs during solidification. Risers are in the production of castings for the purpose of providing molten metal for the solidifying and shrinking casting. Riser design in sand castings requires, at a minimum, that the riser solidifying after the casting. The most important aluminum foundry alloys are based on the Al-Si system, especially the hypo-eutectic alloys with compositions ranging from 7 to 11 wt.% silicon. In the present work blind riser of elliptical and spherical shapes were used    in the casting of “L" section of different sizes. The ratio between the casting modulus to the riser modulus was studied. William′s core was also used to study the effect of applying pressure on the quality of Al-Si alloy. The results showed that the position of the riser and the pouring gate influence significantly the soundness of Al-Si castings. The casting of “L" section with large size showed sound casting when elliptical riser is used, and when the pouring gate was placed beside the riser and relative modulus was 1.5. Also the proportion of feed metal available from the feeder which meets the modulus % C was 9.7. Sound casting for “L" section of small size was observed when the spherical riser with relative modulus 1.0 was used and the % C was 8.4. Using the spherical riser in this case leads to save the material by 20%.