Hi Chris,
A bit about pulse jets on the site is here
http://madmodder.net/index.php?topic=648.msg3887#msg3887Plus a site with plans to get you making the valveless types.
I think somewhere, I have the plans for a fully working version of the petal valve type you showed in your post, but they do consume the valves at a fair rate.
I showed a bit of interest in these a few years back, when they were being used for tethered model hydroplanes. But I think they died a slow death because of the noise issues.
There were a few German manufacturers still making them, last time I was at Nurnberg toy fair. A fair few years ago now though.
John