ripping four by fours

Just buy a 2x4 instead of wasting a perfectly good 4x4.

Well you can do that if the end result can be less than half of a 4x4.

A 4x4 is 3.5" x 3.5" A 2x4 is 1.5" x 3.5"

I used to cut a slot about 1.5" deep on both sides of the piece and use a recip saw to take out the center.

replying to Electric Comet, Iggy wrote: Provide a picture if you can. 4x4's are typically from the center of the tree, so you pick a grain most matching your blade and go with it or parallel. It's easiest and kindest to your blade. This, will also give you 2 sticks that are vertically stronger, more stable and fairly equal to each other. Closely match a split log and you'll be structurally optimized.