valve leak?

[Mike Taylor 3601]

It depends on how much it's bubbling, It is almost impossible to get valves sealed to point where they won't bubble,whether water,soap& water etc.
If valves/seats have'nt been lapped in you may do that and see improvement,tap on valves so it bounces them off seats sometimes helps also.
I leak valves on engines by hooking air straight in plug hole I have 160 psi air in my shop
I have rockers removed,I cover ports with hand to feel for leakage if is leaking you will feel pressure build against your hand,lots of times you can tap on tip of valve and will seal.
You can have valve job with 100% seal on vacc.tester and still bubble soap.
The most accurate thing you could do is use leakdown tester with heads on engine.

If you have more air press available see if that makes worse or better.
Mike Taylor 3601