Grapefruit Chiffon Loaf Cake

1 c. flour
1/3 c. grapefruit juice
3/4 c. sugar
4 egg whites
1 1/2 tsp. B.P.
1/4 tsp. cream of tartar
1/4 tsp. salt
2 tsp. grated gf peel
1/4 c. oil
1/2 tsp. vanilla
3 egg yolks
1 to 2 tbsp. gf juice
1 1/2 tsp. grated gf peel
1 c. sifted 10X sugar

In a large mixer bowl stir together flour, the granulated sugar, the baking powder, and salt. Make a well in center of dry ingredients. Add in order: oil, egg yolks, the 1 1/2 tsp. grapefruit peel, and the 1/3 cup juice. Beat smooth with electric mixer. Wash beaters thoroughly. In a medium mixer bowl beat egg whites with cream of tartar till very stiff peaks form (tips stand straight). Scrape the whites over the flour mixtureand fold in gently. Pour into an ungreased 9x5x3-inch loaf pan. Bake in 350 degree oven for 23 to 30 minutes or till cake tests done. Invert; cool in pan completely. Loosen edges of cake and remove from pan. Combine remaining grapefruit peel, vanilla, and enough juice with the powdered sugar to make an icing of drizzling consistency. Spread over top of cake, allowing some icing to drizzle down sides.