How do I tell if a mercruiser v8 has been frozen?

[rov_aaaa]

How do I tell if a Mercruiser v8 engine has been "frozen"/Cracked?

Its a mid 70's boat, with a mid 70's Mercruiser v8. How do I tell if the block has been frozen?

The engine hasn't been run in a few years, so I don't know if I could start it, but I could certainly bring a battery and do a compression test, would that be indicative?

What should I look for as signs that it was frozen? What kind of damage occurs when it freezes?

I'm looking at a 26 ft, 70's Cabin Cruiser hard top for sale. Although the boat is a little older, its still very nice. However the out-drive is missing, and I just don't believe that anyone would remove the out-drive off the boat, making it no longer a nice complete running boat, unless there was already something majorly wrong with it, like the engine being frozen.

 

[Snobike Mike]

Re: How do I tell if a mercruiser v8 has been frozen?

I think unless you can run the engine there is no way to be sure.

Just doing a compression test won't run water through the entire block and you won't be able to see/find a hairline crack unless you see water coming out of it.

Good luck.

 

[bruceb58]

Re: How do I tell if a mercruiser v8 has been frozen?

only sure way is to pressurize the cooling passages with air.

 

[fossill]

Re: How do I tell if a mercruiser v8 has been frozen?

If the engine suffered freeze damage the engine block will crack, either externally or internally or both.
Before you part with your money, do a compression check, which by the way wont tell you thing about a cracked block.
After a thourough look over, take it out for a sea trial for a few hours with the owner. Bring along a knowledgable boat person/mechanic type for an unbiased opinion. If the block is cracekd, it will either leak externally, internally into the oil system (milky oil), and or overheat depending where the crack is.
As for the outdrive, some people take them off and store them inside so they dont dissappear from theft.

 

[cr2k]

Re: How do I tell if a mercruiser v8 has been frozen?

Most common place to crack is just below the head in the valley under the intake manifold. How will you know this? Run until warmed up and check for water in oil. Or pull the manifold and inspect.