Just about finishing up making improved Homebrew Valve Spring Compression Tool.

BUT, how much do I need to depress or compress the Valve Spring Cover to expose the Split Collets sufficiently to remove them?

Thanks

I'd have to say that the retainers are in the area of 3/8" tall. If you can get 1/2"-5/8" compression on the spring you should be ok.

Mark

It partly depends on how much access your gadget gives you once in place. It is possible to extract the collets one at a time from a partly-compressed valve if you push the holding cap to one side and fish the collet out from the enlarged gap with fine nosed pliers. But for easy all-round clearance you need at least 1/2" I'd say.
There was a lengthy recent thread on making compression tools. I contributed my bit, but someone else came up with photos of a much cleverer (but more complicated) tool.

Thank you

Hey, let us know what kind of contraption you put together and how well it works.

Mark