Mercruiser 165 Straight 6- Water leaking

[4327]

Good morning all.
So I am kind of new to the I/O world.
My recent purchase is a 77 Glastron with the 165 Inline 6 (Merc)
Bought the package for the trailer but If I can get the Boat/Motor to a point where it runs well I can make some cash back.
Ignition issue from yesterday is solved thanks to members here.

Running the engine with muffs in my driveway.
Boat is level.
When running I have water GUSHING out.
Seems to be coming from between the block and the Exhaust manifold around #5 or 6 cylinder.
Cant see where due to location being high on the engine
Compression on all cylinders is in the 150lbs (+/- 3) range.
No big deal if its a cracked block as I really have no money in this project.
I am hoping maybe just a gasket?

I have the tools and the time so I am going to start taking off the manifold shortly.
Any advice?

Thanks in advance.

 

[alldodge]

The manifold is cracked would be my guess

 

[kenny nunez]

You might be lucky and the leak may be one of the small core plugs in the side of the head. They are about 1” in diameter.
You have to pull the manifold any way. Good luck

 

[Bondo]

Seems to be coming from between the block and the Exhaust manifold around #5 or 6 cylinder.

Ayuh,...... Welcome Aboard,..... Ya got a Cracked Block,.....

Right at the corner, where the deck meets the sidewall,...

Ya might see rust tracks with a mirror, of digital camera,....

Pull the manifold, 'n it'll be Obvious,.....

If ya decide to go shoppin' for a replacement long block,.....
Make Sure it has the extra cast horn, forward starboard corner of the block, the motor mount bolts too,.....
Many I-6s don't have it,....