Changing valve springs on car

I tried the rope trick first and had a hard time getting it to seat the valves correctly,so I opted for the air method. The lead from the compression gauge worked great and I kept the pressure around 100 lbs. It took about 2 hrs. start to finish and with a helper I probably could have cut that time in half. Compressing the spring with one hand while working the retainers on with the other was a test of my dexterity. With someone else to put the retainers on it would have gone really fast. All in all ,it worked great, and I`d recommend it as an inexpensive tool that worked without a hitch.