Preheat the oven to 350 degrees F (175 degrees C) and grease a 9x13 inch baking pan.Sift together the flour, baking soda and cinnamon in a medium bowl and set aside.
In a large mixing bowl, combine the sugar and oil until well blended.Beat in the eggs one at a time and add the vanilla extract.
Stir in the flour mixture just until incorporated.Fold in the pineapple, grated carrots, coconut and chopped walnuts.
Pour the batter into the prepared baking pan.Bake for 45 minutes, or until a toothpick inserted into the center of the cake comes out clean.While the cake is still warm, use a fork to poke holes all over the surface.