I have a 13 hp kawasaki engine that I plan on using for a rear steer mower. Think grassopper, but mechanically rear steer. I've also picked up a 60" grasshopper deck and a differential from an EZ-GO golf cart. My plan is to run a hydraulice motor mounted on the diff through a forward/reverse spool valve. I have a couple questions regarding pump and motor sizing and hp requirements. The blades will be direct driven via belts. Do you think 13 hp will be enough for all this? Where can I find info to size the pump and motor or does someone have suggestions? I would like the pump to be a little oversized because I'm considering a small bucket or blade to be used when the mower deck is removed. Any other suggestions or questions? My father in law had built one with TRW wheel motors instead of the differential which may be a better idea. When he passed away it was sold with the estate so I can't get any design info on it. Trying to build my wife a similar one for memories I guess. Thanks in advance.

http://www.machinebuilders.net/forum/upl..._and_Torque.zip

Under the Hydraulics forum on second page of hydraulic motors is an Excel file that I have written that has everything you need. The link is on the old mnb site as shown above.

Hydro-gear pumps and hydraulic wheel motors are the way to go but will cost some. Even on eBay. Not to mention getting two hydraulic motors exactly the same. Direct drive 150 to 250 cc should be OK with 195cc being real close. If you are not munching your grass 13 hp should be more then enough. Depends on speed wanted pump and tire size as to what size motor you want. My program has a mph calculator. Just put in the tire diameter and rpm. Direct drive you would use 1:1 gear ratio.

The hydraulic motor will drive the golf cart diff most likely. I still need to dig it out and find the gear ratio on it. Thanks for the direction.