Preheat oven to 325°.
Mix oil, sugar, eggs, and vanilla. Beat well until light in color.
1 c. oil, 1 1/2 c. sugar, 3 large eggs, 2 tsp. vanilla extract
In a seperate bowl, mix dry ingredients.
3 1/2 c. all-purpose flour, 1 1/4 tsp. salt, 1 1/2 tsp. baking soda, 3/4 tsp. baking powder
Add zucchini and dry ingredients alternating with pineapple. Mix only until combined. Do not overmix.
2 c. zucchini, unpeeled and grated, 1 c. crushed pineapple, drained
Stir in the chopped walnuts.
1 c. walnuts, chopped
Divide the batter into two well-greased and floured standard-size bread pans, and bake for one hour or until a toothpick comes out with just a few crumbs.
Let the bread rest in the pans for about 10 minutes before carefully removing the loaves. If the loaves don't want to slide out, run a knife around the edges to release.
Cool. Store in an airtight bag or container.