I guess the easy answer would be to go to the or a strip out near Samut Sakhon and have a look but maybe there is another way if anyone knows. I'm not hip enough to discover where the impromptu ones are!
Specifically I will be looking for a class with Honda engines. Logic says that there may not be as water cooling is heavier than air cooling but there might just be a Honda class?
I've scoured the magazines in 7/11 but...
Update: I've "recruited" my 14-year old neighbour to do some surfing! So I'll see what he comes up with.