Hi,
After 1 day of testing (i have some days off) i can confirm that the use of a turpentine bubbler is a better choice.
The engine is knocking less, so that would mean that the turpentinebubbler has a positive influence on the burnrate of hydrogen. So, i will continue with turpentine as burnrate reducer.
I also tried exhaust gasses. I collected them and feed them in my intake. Nothing noticable.
well, all tests are of course done on my little working setup as an amateur researcher with no good measurement equipment, except my ears, eyes and ampmeter and scope.....
I do have have lots of experience with bike and car engines, so i know how an engine should run, sounds etc......
hopes this all helps you with your research!
steve