Valve seals

I am doing valve seals on my 305 and I dont really what type of compressor to use. Will those 12v tire compressors work? They give some high pressure, but dont flow much. I know that they could probably work, but threre is a doubt that the cylinders even at TDC leak a lot so the input is not sufficient to gain 100PSI. Or am I wrong?

Also I heard about putting a nylon rope into the cylinder to keep valves from falling in. Its an option, but I dont like the idea of having to break the keepers while the valves contact rope or piston. How much abuse can it do?

any ideas?

anyone?

if its an everyday driver i would definately get a bigger compressor..i have always done them with bigger compressors the smallest being a 10 gallon but the nice thing about them is they have a pressure regulator..i wouldnt want to risk dropping a valve...if this is easy to get i would go with that...but i wouldnt do the rope trick unless you have to...just my opinion...how many miles are on this 305 ??

140 miles, not that bad. I have got 180+ psi on all cylinders and I would like it to stay that way. It has lotsa power and runs awesome. I did the intake gaskets and saw a few drops of oil on valve steams and now it gives a little blue at warm start ups. The only thing I dont get is why cylinders leak that much so I gotta use a 10-12 cfm comressor. Strange. I though they leaked no more than 5 per cent, so even a mini copressor should pump them to 100 psi.
Thanks for your response.

Have done this before and you absolutely need a large air compressor. Not a monster, but definitely not a 12 volt toy.

Awesome, thanks for the answer. Would a 3 galon electric work ?
I dont have a place to plug it in now I live in an apartment building.