Exhaust Manifold test

[Chief123]

1986 4.3 OMC Cobra
Recent purchase. Blocked cracked in valley.
Have Long Block ordered.
Any way you can pressure test the exhaust manifold for water leaks?
Thanks for any help.

 

[Bondo]

1986 4.3 OMC Cobra
Recent purchase. Blocked cracked in valley.
Have Long Block ordered.
Any way you can pressure test the exhaust manifold for water leaks?
Thanks for any help.

Ayuh,..... Are they one piece, or manifold/ risers,..??

 

[Chief123]

TKS,
They are original 1 piece type.

 

[jerryjerry05]

About the only thing you can do is:
Set the manifold upright so it's level.
Then hook a hose to the inlet.
Turn on the water and see if any water comes down into the exhaust chamber.
The 86 if it's original it should probably be changed.
They have replacement manifold sets that take the place of the old batwing style.
Cobe Marine in Pasadena, Md. They sell replacements for the batwing.

 

[Chief123]

Thanks. I've found a new set of the two piece type for about $750.. I know that is better than buying another long block. However, this project hole keeps getting bigger an bigger :}.
I assume one main reason for using the exhaust as part of the water discharge is to help keep the engine compartment temp down. Otherwise I would think one could easily plumb the water to each of the lower exhaust pipe? However, the rubber connectors may not be able to withstand the exhaust heat with o water?
Oh well for now just need to get the new engine here and put back in and finish up the work on the drive, floor and other items on my To do list..