1969 Mercruiser 165. Small water leak from under manifold.

[TheShadow619]

1969 Mercruiser 165 Inline 6. I have a small trickle of water from under the manifold between cylinders 1 and 2. I'm hoping that it's only the freeze plugs, but I know it could be the block or head. I know I need to pull the manifold off to check it out. My family has owned this boat since 1979. As far as I know the manifold has never been off. In looking at the length of the bolts I see a great possibility of breaking them off. Any advice before I dive in?

Other question is, can I use a standard manifold gasket from a 1696 Chevy 250, or is the marine setup special?

 

[Fishermark]

I guess the data loss with the upgrade took out my answer from before.... but the manifold is going to have to come off one way or another. Don't be afraid of the bolt / nuts - you never know if they are seized up till you try to remove them. Here's what you will see underneath. There are core plugs in th ehead and the block.

 

[TheShadow619]

No Title

It must have deleted mine too, but here's what I found.


Well... Good news and bad news.
The good news--- The bolts came out easily, the manifold came off easily.
The bad news--- The block is cracked. Had a lot of rust built up over it. Chipped it away, and the water started running. I'm pretty sure I can V it out and JB Weld it. It's between the cylinders, not into any freeze plugs. It worked on an old Chevy pickup I had as teenager. It's definitely worth a shot here too.

 

[TheShadow619]

No Title

Here's a couple pics.

 

[TheShadow619]

No Title

Here's a couple pics.