We took a 17.5 Horse Power engine and made a frame for it out of 4" by 4" 1/4" thick wall square steel tubing. The tubing is welded together and compartmentalised into 2 sections. One to be filled with fuel and the other to be filled with hydraulic fluid. There is a hydraulic fluid pump attachment on the underside and the frame also has latches so it can hang off the back of our open-source tractor we made. (Search for "LifeTrac II tractor" in google).