Aren't those blocks of reactive armor explosive?
Tank rebuilders do amazing things to get a whole vehicle out of several. There are Sherman resto's out there with the hull made of two or more salvaged tanks. Why would tank engines be any different than any other vehicle or industrial engine? If 65 year-old Maybachers can be made to run, why not Russian engines. They are most likely adapted truck or tractor engines.
Many years ago, when the Interstate highway system was first being built, a section of I-80 was going through Paterson, NJ. The route was to go through the old silk mill district. One local demolition contractor had the bright idea of using a Sherman with the turret removed and a piece of plate welded over the hole. He was going to run the tank through the buildings to knock them down. The first building he ran the tank through had a couple of levels of sub-basement and when he drove out onto the wooden floor, the thing crashed into the sub-basement. It took quite a while to get him and his broken back extracted and the tank is probably still there, buried under the interstate. If I recall correctly, the demolition contractor was Vinnie Ottillio.
Russ