Mercruiser V6 seized from Rodent Damange

patman · 08-05-2011, 10:51 PM

A lot better, but...no, not good enough. Load 'er up again for another soak.

In theory, a hone would do it because you just need to clean it up, but remember that is taking material off of the cylinder walls. The bigger you make the hole (and that's relatively small amount, it could be .001") the sloppier the fit, and the worse the compression/burning oil problems will be. At some point it gets loose enough that an overbore is the only answer. Once you get to that stage, you've jumped up in cost, and you should overbore all 6 holes (probably .010" or .020"), buy pistons to fit the bigger holes, have the rotating assembly balanced, etc, etc.

If you want to roll the dice, soak it for another couple of days, and see what it looks like then. Maybe going over it gently with a fine grade scotchbrite periodically. The bore needs to be smooth enough to not catch your fingernail on anything.

08-05-2011, 10:51 PM	#30
patman Senior Member Join Date: Jun 2008 Location: NH Posts: 380 Thanks: 56 Thanked 156 Times in 78 Posts	A lot better, but...no, not good enough. Load 'er up again for another soak. In theory, a hone would do it because you just need to clean it up, but remember that is taking material off of the cylinder walls. The bigger you make the hole (and that's relatively small amount, it could be .001") the sloppier the fit, and the worse the compression/burning oil problems will be. At some point it gets loose enough that an overbore is the only answer. Once you get to that stage, you've jumped up in cost, and you should overbore all 6 holes (probably .010" or .020"), buy pistons to fit the bigger holes, have the rotating assembly balanced, etc, etc. If you want to roll the dice, soak it for another couple of days, and see what it looks like then. Maybe going over it gently with a fine grade scotchbrite periodically. The bore needs to be smooth enough to not catch your fingernail on anything.