Piston Damage?

[SavinRaven]

Hi Again,
So this is the first engine I've torn apart so sorry in advance for all the questions. I have been manually rotating the engine to be sure it doesn't seize up while its out on a weekly basis and noticed yesterday I guess because the piston was coming up and down some damage to one of the pistons... I dont know if this would cause an issue or not. It looks like a bolt or something fell in there and caused the issue but I didn't find any metal however I did find one piece of rubber. (This could have fell in when removing the head) My work space is poorly lighted and kind of cluttered right now... I guess my question is should this damage be addressed before I put the head back on? This is a 1973 mercruiser 250 ci Inline 6. The reason for taking the head off was to replace head gasket and exhaust manifold gaskets/ manifold and riser from a previous overheat. Its worth noting the damage doesnt go through the piston its just on the surface all rods were in good condition.. the head is reman'd and was going to go back on this weekend until i noticed this...

 

[Scott Danforth]

post a full-size version of the pic

looks like old damage. I would run it.

Then again I ran a 4.1 Buick V6 with 3 carburetor screws mashed into a piston for about 60,000 miles

 

[tank1949]

Very clean piston top. Did you clean it or this is how it appeared? Perhaps factory defect or blemish? Has motor been rebuilt by someone else since 73? Is it a salt water used old block???? If so, I'd get another one! If fresh water used and you did not have negative symptoms, I'd do as Scott stated. You have already performed a lot of work! Good luck!

 

[Scott06]

post a full-size version of the pic

looks like old damage. I would run it.

Then again I ran a 4.1 Buick V6 with 3 carburetor screws mashed into a piston for about 60,000 miles

I would second this , run it. All you have to loose is the labor for cylinder head install.

I had a spark plug center electrode drop out on a toytota 3.3 V6. Wife said the engine is making noise. Rattling tapping etc from top end , nothing wrong with valves, first plug I pull was missing the electrode... let it idle for 30 minutes noise went away for most part, a little noise the next day, changed the plug and drove it for several more years.

 

[Rick Stephens]

Then again I ran a 4.1 Buick V6 with 3 carburetor screws mashed into a piston for about 60,000 miles

People will do the strangest things. LOL