Replacing Valve Seals W/O Removing Head

[MaxM357]

Hi,
I am going to be attempting to replace my valve seals without pulling the head off. I will be using a leak-down tester to supply pressure to the cylinder to keep the valves in place. I am wondering if anyone has done this before and if they have any tips and tricks before. Mainly I am wondering if it is possible to do this job without removing the timing cover?

Thank you in advance for your help!

 

[Easter Bunny]

Back in my pinto days people would push rope into the cylinder through the spark plug hole to hold the valves up when changing the valve guides I wouldn't trust the air pressure to not slowly leak out

 

[MaxM357]

Back in my pinto days people would push rope into the cylinder through the spark plug hole to hold the valves up when changing the valve guides I wouldn't trust the air pressure to not slowly leak out

It is definitely an uncomfortable thing to do but I have done it plenty of times on other vehicles. And if the pressure is leaking out, you've got bigger issues and might as well pull the motor haha.