Lookin for any pointers in Pressure testing cmi e-top headers. The riser seems to be pretty straight forward. Plug up the exit with a bung and pressurize the inlet. Any tips for the tails? Inlet again is easy...no idea what to do with exit where water comes back into exhaust.

How about trying a rubber expansion plug from Home Depot plumbing dept. That should seal the internal pipe.

They make 4" expandable plugs?

Yes, called "test bulbs"

That's what I used to test my headers

Take your pick
https://www.zoro.com/pipe-and-test-plugs/c/7374/

This works for me.

http://m.homedepot.com/p/4-in-Rubber...B&gclsrc=aw.ds

All good suggestions. Purchased a 4" inflatable test plug. Didn't work. Tried to position it 10-15 different times. Wouldn't seal. Ended up placing the test plug in the straight section of the pipe and putting an end cap on the end. Still could only get 8-10 psi out of it before it blew out.

What I did with Lightning headers was to put a short piece of 4 inch hose over the inner pipe where it extends beyond the outer collector. Then I put a piece of 5 inch over the collector and clamp it to the collector and two clamps to collapse the other end down onto the 4 inch rubber hose and this clamps the 4 inch onto the inner tube. then apply water to the water inlet manifold. IF there are nuts welded onto the inner tube to hold the tails on just cut a hole in the 4 inch hose to go over the nut. works every time. IF you can't clamp the 5 inch down onto the4 inch tight enough wrap the 4 inch with some duct tape to take up the space.

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