1971 Inboard Mopar 440 with LOTS of water in oil...

[crappace]

I have a 1971 Century Coronado with lots of water in the oil I just bought last October. It ran great when I put it away but now after 10 hours of running it this spring had 1-2 gallons of water mixed with the oil. Compression test showed low compression in three cylinders, again, it runs fantastic.

I pulled the heads off and as you can imagine it looks like a vanilla shake exploded and is covering the rockers...the area under the carb but the cylinder walls and piston tops look perfect. There was about 1 ounce of water in the cylinder with the worst compression, 55#. I'm assuming its either a warped head or blown gasket.

I need to check the heads, replace gaskets and clean up the motor. What is the best way, other than yanking the motor, to get that oil/water sludge out of the pan and all the other places it worked into?????

Thanks,

Brent

[delcecchi]

When you winterized it, did you get antifreeze or air into all those water passages in the block and head?

Often these I/O motors just use lake water for cooling in an open system. So when you put it away for the winter you need to make sure that there isn't water left in the motor to freeze and crack something.

[Surface Tension]

Cracked or rotted out exhaust manifold, bad riser or gasket are a couple a common things in I/Os. Did you drain the block and exhaust manifolds last fall?

Drain the oil, fill with oil, and run it without the muffs on for a minute. Let cool and repeat.

Drain, fill and run again. Repeat. Its not doing your impellor any favors running dry but that is easy to replace.

[boatfixer]

It's been asked already but did you drain the water out of the block and manifolds prior to freeze up last fall?

Did you look closely at the inside of the block (water jacket) behind the pushrods for cracks?