Dude, I have a new hobby, built 4 of these things.
Take 2 lengths of 2X8 22" long. Use some other scrap 2X12 maybe 2 feet wide, or whatever for base laying flat,crosswise.
Stand the 2X8 on edge (22" horizontal, 8" vertical) and screw to your cross pieces leaving a 8.5" to 9" gap. Cut some 2X8 triangles at 45 degrees and screw them in as braces between the 2X8 and the base pieces.
Drop oil pan in to long slot, will rest on pan rails.Ratchet ties on all 4 corners of motor.Also easy to unload. Saavy?