just wondering are catch cans or can catch cans be designed for legal use on the roads??

yes. Cannot vent to the atmosphere, must have a line returning the oil to circulation. So with a filter=no With a line at the bottom running back to engine=yes Does that defeat the purpose of bleeding the excess pressure/vapour? sort of, but only in a worst case scenario, should still work fine.

were do most people run it back into circulation

Into the intake. Other option is run the hose over the back of motor so it "looks" like its hooked up but really just vent it next to the box etc

Im currently making one at the moment for a blown application, i want it legal so it will be a water/air/oil separator. Lines from rocker cover go into can that has internal tubes that run to the bottom of the can thats filled with stainless steel wool. A pick up at the top that runs back to intake. keeps it legal and keeps oil out of the inlet and stopping detenation.

thats a mad idea mate

sh1t wanna hope ALL THAT WOOL stays in the can.... =O

Its top quality red dot steel wool, none of this cheap **** Its the stuff used for washing up so it fairly rugged not that steel wool you get that is realy fine. Some original photos have not been recovered yet.

pickup at the top of the can? wont it then need to be full before it recirculates?

nah its a return for the air that goes through the can, not the oil. its so its not vented to atmosphere

yeah thats correct, will have a drain at the bottom to.... well drain it and get the oil/water residue out, should of got some pics of the inside before i welded it together. The to pipes that run to the bottom also have a few holes drilled in so the surface area for venting id higher that just the hole at the bottom.