How to pressure test EMI thunders..
 

Well after the dreaded milkshake oil. I pulled the upper end of the motor. Pulling the starboard side header there was water in the bottom of the last three exhaust and water on top of the pistons. So I think that is the cause of my milkshake issue. Cause I didn't see any blown head gasket evidence or intake problems. So how can test these headers???

anyone??

stand them upright on bench or ground. fill them with water thru the water feed hose on bottom of manifold till water comes out the riser. look inside exhaust passages for dripping down from above. it's only 1 atmosphere pressure test, but if they are that bad, u will probably see it...

Somebody stated filling a manifold with acetone works very well. Go into the whats new section of the forum and there is a thread started for testing with acetone. I personally fill the manifold with piping hot water to recreate the runninng condition and then pressureize with a coolant pressure tester after blocking off all the ports. You have eddie marine? Does the water transfer from riser via hose or water jacket? Also keep in mind if your cam is biggerthan stock you can have reversion.

So I am also dealing with a milkshake oil situation and I believe I traced it down to a cracked manifold.

with the manifold still on the engine, I capped off the riser jumper hose outlet and I pressurized the lower inlet to 20 psi. It was losing pressure immediately and I could hear air leaking out the exhaust flapper.

im going to pull the manifold off, screw on a water hose to the lower manifold fitting and leave the upper riser outlet capped off. Figure the water will leak out of the crack once pressurized and show the location??

That doesn't make sense. Are you checking the manifold or the riser?

so I’m trying to check the water cavity in the manifold. Please let me know if I’m incorrect in my assumption of how to test the manifold.

these EMI manifolds have a large 3/4” npt inlet at the bottom of the manifold that I believe fills with water from the bottom up. Then there is another 3/4 npt outlet on top which has a jumper hose that connects to the tail pipe.

I capped off the “jumper” outlet with a npt plug. I assumed this is the only exit for the water?

Sounds similar to my stainless marine. I pressure tested like I would a air to air intercooler on a car. Capped one side and got a fitting with air fitting on it. Since I run all AN lines -16an lines to my manifolds I just used the same fitting I would pressure test a line with and ran pressure in manifold to 30-35psi and let it sit, and it held overnight. Ill try and pics.