Rope trick works, but is a royal PITA from my experience. Took me HOURS to do just half of the valve seals. The idea is to run a length of rope down into the cylinder with the piston at BDC, then turn the crank until the piston comes up and the rope wedges between the valves and the piston. The only problem is that if the rope gets wedged between the flat part of the head and the piston, it isnt putting pressure up on the valves, and when you remove the spring, the valve falls down about 1/8 to 1/4 inch, and it makes it next to impossible to get the spring compressed enough to fit the keepers. Have to keep running the rope in and out until you get it to actually put pressure directly on the valves, and even then, the rope compresses and makes it a real pain. I would never do valve seals in car again without the proper tools and air supply.