hey guys i have a new suggestion to add to this, i use plastic plates from dollar general (plastic dinner plates red in color) i get about 7 disks per plate with my 2" cam levers, and they come 20 plates for 2 bucks
2 bucks is pretty cheap to make 140 disks
jspellman gave me the idea and told me what to use (he uses them in his hybrid)
they work in my combustion fine, and according to his testing with a burst disk pneumatic they burst at about 60 PSI and when they pop they blow out a whole circle so there is no flow restrictions except for the coupling itself
just thought i'd add this