Beat together oil, sugar and eggs until well combined. In a separate bowl, sift together flour, baking soda, salt and cinnamon. Beat together with sugar and egg mixture. Stir in vanilla. Add carrots, walnuts and pineapple, mixing until well blended. Pour mixture into a greased and floured 9 or 10 inch bundt pan. Bake 1 hour until done (check after 45 minutes). Cool on cake rack, remove from pan and cover with cream cheese icing. Frosting: Cream together ingredients, blending well.