1992 Mercruiser 4.3 Alpha One Gen II has water in oil after rebuild.

[nola mike]

To pressure test a block cooling system:

1) Remove hoses to manifolds and plug them.

And hoses to elbows?

2) Remove the 'IN' water hose, that comes from the transom, at the thermostat.

3) Either plug the open thermostat port or use it to make up a connection to a schrader valve.

4) Apply max 15 pounds pressure to cooling system. Should hold air indefinitely. You can use a mechanics stethoscope to listen for the leaking air as well.

 

[alldodge]

15 will work but I would suggest 30 psi, my motor reaches almost that

 

[Faztbullet]

The intakes like to freeze and crack under the carb..... leaks water into lifter valley..

 

[nic420]

Found out today the starboard sided head on the the #6 cylinder had a crack between the valves. Can't seem to find a replacement for head w/ casting #10144103. I was able to find one on Ebay w/ casting # 10238181 but not sure if it will fit. Please advise if it will work because it looks the same.

GM Chevrolet GMC 4.3L 262 Cylinder Head Assembly 10238181 1992-1995​

 

[Lou C]

GM 1987-1992 4.3 LTR /262 ci - V6 cyl Cylinder Head - Casting : 14098768 (machineworldny.com)

try calling this place and asking them the question. I put a pair of these on my '88 4.3 about 4 years ago. The don't match your casting # but might work, I'm just not sure. The were the same casting # as my OE heads which were also cracked. The pix are the actual ones I installed.

 

[Lou C]

GM 1992-1995 4.3 LTR /262 ci - V6 cyl Cylinder Head - Casting : 10144103<br />14099067 (machineworldny.com)

just saw this...might be what you are looking for....

 

[nic420]

Thank you for all your replies. I contacted the machine shop that rebuilt the heads for me and they were able to get me a replacement.