3.0 L mercruiser 4 cylinder assistance

[BradJCoker]

I am hoping someone can help me out. I have been working on a restoration project on a 1988 Sea Ray. The engine was seized when it arrived. Long story short after emptying the water/oil from the oil pan replacing all gaskets seals and cleaning it up down to cylinder level. It all came back to life.
I know the engine drain plugs are on the port side the guy I got the boat from said he lost a plug that was on the starboard side toward the back of the engine. When the motor is running the hole spits water. Is this normal? If so what type of plug goes in the hole the part of the block has a dual hole a horizontal threaded hole what looks like a lift point and a hole that faces up and that is where the water spits from when running. Any help would be great.

 

[matt167]

It could be froze and split.. post a video or at least pictures

 

[Alumarine]

There is a 1/8" NPT plug that goes in on the underside of the manifold.
It's between the carb and the transom end.

 

[BradJCoker]

Here are 2 pics. Thanks for the replies this is great.

 

[BradJCoker]

There is a 1/8" NPT plug that goes in on the underside of the manifold.
It's between the carb and the transom end.

I am aware of that plug however it is on the opposite side of the block. I added 2 pictures and may start the boat this weekend to add a video. Hopefully a little brighter.

 

[Scott Danforth]

Without the plug in the block you have no coolant in your motor.

 

[Scott06]

This link to an industrial version if the 3.0 shows a threaded block plug there as well as the plug on the port side.
http://www.allpowerlabs.com/wp-content/uploads/2015/05/GM_PSI-3.0L-Engine-Service-Manual.pdf its on page 31in the parts drawing.
i had a 1990 3.0 for many years never noticed a drain plug on that side, maybe later ones have them and yours was swapped fir a newer engine? Either was it would be a standard pipe plug available at any decent hardware store , probably a 1/4“ npt.

 

[Alumarine]

This link to an industrial version if the 3.0 shows a threaded block plug there as well as the plug on the port side.
http://www.allpowerlabs.com/wp-content/uploads/2015/05/GM_PSI-3.0L-Engine-Service-Manual.pdf its on page 31in the parts drawing.
i had a 1990 3.0 for many years never noticed a drain plug on that side, maybe later ones have them and yours was swapped fir a newer engine? Either was it would be a standard pipe plug available at any decent hardware store , probably a 1/4“ npt.

I have a 1974 and 1980 version of the 3.0 and neither have a block drain at the rear of the starboard side.
They do have the oil pressure sensor in that area.