Exhaust manifold removal

Engines, Shafts, Steering, Struts, Rudders, etc.
Aluminum Star
Posts: 180
Joined: Tue Mar 01, 2016 6:50 pm

Re: Exhaust manifold removal

Postby legendlc » Sat Jun 08, 2019 6:21 pm

So I did the old water test today by laying the head flat down and filling the chamber on top of the valves with water(didn't have acetone) I placed paper towels under the exhaust ports to see if I was getting any drips. It appeared that the end of the head closest to the front of the motor that was really rusty was dripping one drop about every seven minutes. The two middle we're a drop maybe every hour and the last cylinder was dry as a bone. It's strange as that's the one that was totally full of antifreeze for the last 10 years.
I then tried placing the head on it's side and filling the exhaust Chambers with water to see if the leaked past the valves and obviously the ones mentioned above were leaving at various degrees. But here is where I'm lost. One cylinder wouldn't hold water at all at after looking at it it's port is open to the intake it appears. I'm no mechanic at all but this is very confusing.
1978 37 Double Cabin
Lake Cumberland KY

Site Admin
Posts: 1320
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Exhaust manifold removal

Postby Fastjeff » Sat Jun 08, 2019 6:40 pm

Hah! That's probably the exhaust crossover passage (designed to heat the carb).

"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

User avatar
Royal Aluminum Star
Posts: 351
Joined: Tue Jul 15, 2014 12:21 am

Re: Exhaust manifold removal

Postby Busia » Sat Jun 08, 2019 7:39 pm

As Jeff says that is probably to heat the carb, or actually the little coil that takes the automatic choke off. If the valves don't seal, I would depress the spring to open each valve and look at each one. It's easy to lap them and clean them and re-assemble. If they are real bad you will have to replace or grind them. You can pay to have all of this done or save by doing some of it yourself.
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW