Re: Mercruiser Engine Help
Sorry Intrepidvoyager. This is not a flame but you are way off.
I agree that a core plug may be forced out by freezing but that is not the design or intent of the plug.
Nice attempt at a engineering type explanation. True the bottle was a poor attempt at explaining it. Your are unfortunately wrong. I should have replied with the service bulletin.
They are designed as core plugs. Sorry to have mislead you.
Even with your experience you misidentified their true purpose. That is why your example has a 50% failure rate. Proof again that a common slang term has defined the use of part and how it is sold and continues to be spread even though it is false information regularly accepted as true by the uniformed.
You are missing the main point. I did not make the original statement.
The definition was made by the Mercruiser Engineers.
In fact my original comment earlier in the thread had a link to the sticky that includes a link to the service bulletin. This subject has been beat to death on this forum. That is why the sticky was posted. Too bad you skipped using the link I added to my original post. I am not trying to make you appear dumb or stupid. I would say that in the past 40 years you have remained uneducated as to the real purpose of the plugs. Now you know the truth and can help spread it.
Welcome to the ranks of the core plug educated.
Please tell the rest of your associates the true purpose by printing the service bulletin. Even us old guys can always learn something new. And by explaining this to your customers, you may lose some work but they will save the cost thinking FREEZE PLUGS may save a block.
See the Service Bulletin at this link.
http://www.boatfix.com/merc/Bullet/87/87_14.pdf
Excerpt Quote from the Mercruiser Service Bulletin Number No. 87-14
Boldface is their designation:
Freeze Damage To
MerCruiser Engines
Freeze damage to MerCruiser engines is usually
identified as a horizontal crack that has one edge of
the crack pushed out slightly. A freeze crack in the cylinder
block usually happens just below the core plugs
or along the upper edge of the cylinder block just below
the cylinder head (Figure 1). V-6 and V-8 engines
can also crack below the intake manifold in the valley
area of the block (Figure 1). Exhaust manifolds and
exhaust elbows can also crack from freezing. Heat
exchangers, oil coolers, and transmission fluid coolers
that freeze can either crack a cooling tube internally
or push out the end caps.
All MerCruiser engines have the water drained out of
the seawater section of the cooling system in the factory
test cells upon completion of testing. This is done
to ensure that engines will not freeze during shipment
or storage.
Because of the precautions taken by Mercury Marine,
freeze damage to MerCruiser products is not a defect
in material or workmanship and will not be covered
by our warranty policy.
IMPORTANT: Core plugs, often called freeze
plugs, are not designed to pop out when a block
freezes. A core plug is installed to cover a casting
hole where sand was removed when the block
was cast. The block will normally crack before the
core plugs pop out.
I rest my case
