Water in cylinders

[JRegier]

Hey everyone, I've got a 1981 140HP that I just picked up; when I bought it from the guy he gave me a bit of a back story, long story short he found water in the #3 cylinder and a mechanic apparently tried shaving the heads and replacing the head gaskets but the guy was still getting water. I found the exhaust cover bolts weren't even torqued down and there was some exhaust leaking down the exhaust cover from around the bolts
I'm wondering if that was probable cause for the water intrusion, I already took the exhaust cover off to inspect the manifold And it looks good, the only thing I didn't like is some scoring on the #3 and #4 piston skirts. I'm wondering if the scoring could have been caused the the water intrusion not allowing proper piston expansion and leading to piston slap or if there's something else going on here. My next step is to pull the heads and check the cylinders, if they look good it'll be 4 sets of new rings and 2 new pistons.

 

[Bosunsmate]

you can pull the bypass covers and check the rings that way, that way you see the rings directly

 

[racerone]

?????-----With the exhaust cover off the poster can see the pistons through the exhaust ports.----The hot side of the pistons.-----Actually gives a better picture than looking through the intake ports.

 

[emdsapmgr]

Basically, there are a couple of ways for water to get into the engine: 1. leaky head gaskets 2. Leaky exhaust gaskets 3. from the oil tank on a VRO equipped engine 4. From a hole (casting porosity) in the inner exhaust cover . Yours does not have the VRO that year. Leaky exhaust gaskets and leaky exhaust cover tend to leak water into the exhaust chest and seem to affect the bottom (lowest) cyls first. Scoring on the lower cyls is not good. Indicates lack of lube or insufficient fuel to keep the cyls cool during combustion. Possibly a secondary problem-maybe separate from the water issue. When water gets into a cyl, it tends to extinguish the fire, keeping the cyl much cooler... You will want to tear the engine down to determine how much cyl liner wall scuffing has occurred. (the pistons are scrap, so don't worry about them). If there is any aluminum piston transfer ( scuffing) to the cast iron cyl liner walls, it will have to come off.

 

[JRegier]

Thanks for the info emd; the bottom 2 pistons are both scuffed up and I can see some aluminum transfer in the #3 cylinder (I didn't have the heart to check #4) once I get it out of my truck I'll be pulling the power head to see if there's scoring under the aluminum. If the cylinders are scored then I might use the exhaust manifold and carbs on my 1990 100hp to upgrade to a 115hp if I ever get around to rebuilding it.

 

[JRegier]

Just realized whoever rebuilt the power head (0.25 oversized pistons) didn't use the correct gasket for the block to exhaust manifold. I'm sure that didn't help the poor motor. Due to the odd size of the pistons I think this motor is going to be parted out.

 

[emdsapmgr]

You can still go to .030 over factory pistons. A small dose or muratic acid will dissolve the transferred aluminum and won't hurt the cast iron cyl walls.

 

[JRegier]

Yeah, but the biggest thing against this motor was to not bore the block, I'd rather sink my money into my 1990 100hp if I'm going to go ahead and get a block bored out. I guess it depends if the #3 cylinder looks good and if I can find out the manufacturer for the .025 pistons and replacements. Just as a side-note, they used a 317914 gasket instead of the 323469 gasket. I've yet to rebuild a motor and I couldn't imagine making such a rookie mistake :twitch: the smaller center water channel at the bottom didn't even have any gasket material around it...

 

[JRegier]

Just realized something, the stamping on the piston is definitely .25, perhaps it means .25mm which would put it at a .010"... just need to know which company would stamp 100-110-04P into the top of the piston crown
I think it might be WSM??

 

[emdsapmgr]

The prior assembler evidently did not pay attention to the factory parts diagrams when installing the inner exhaust gasket. Agree, a rookie mistake. The 914 is used as the outer gasket only. Also, best to re-torque those exhaust cover bolts after the engine goes thru a few heat/cool cycles after any rebuild.

 

[Faztbullet]

WSM, Red Rhino,Tech2o, and Vertex are stamped .25mm and all are made by WSM except Vertex.