I've owned 5 boats in the last 15 years, 3 of which have been ski boats, all with chevy 350's for a power plant. So that's 15 years of winters that my skiboats have survived. That streak ended Saturday. I untarped the boat, put all the cushions back in, put the batteries back in, made sure the plugs are in, then headed over to the ramp. Dropped the boat in and it fired right up. I parked the car while my wife idled by the dock. I got in the boat and we started moving out of the no wake zone. I was fiddling around with, and my wife said "something doesn't feel right, it feels rough all of a sudden". I stopped and paid attention, she was right it was running very rough. I opened the engine hatch to see water pouring out the side of the engine. I told her to head for the ramp immediately. I thought a freeze plug came out. We got back to the ramp and I look again. This time there was a bunch of oil mixed into the water. Check the dipstick, and got chocolate milk out. Got the boat back home, cleaned up the bilge area and started looking around and found this:

Blown engine by kdrieber, on Flickr.


I'm thinking a re-power is going to be the diagnosis, but I have to wait till Tuesday to even call the dealer to see when they can get me in to look at it.

This winter has been and continues to be a total pain.

Flies, Floats, or Fucks —> Rent it.

OR

Bring
Out
Another
Thousands

Hopefully its just the head.

I really haven't had much trouble with any of my boats. This is the first major issue I've ever had.

I actually made money on my first Mastercraft, My second Mastercraft only cost me about 230/yr to own and operate it.

I've had this Malibu for 2 years now and this is the first issue its had. Its a 2008 with about 950 hrs on the engine.

My pontoons have been bought dirt cheap and they run and look like it, but they do run and I don't care if the dogs run all over them or kids get dirt and sand everywhere.

A friend parked his 350-powered boat and headed off on a two-week vacation some years back, not anticipating the freeze that occurred while he was gone, didn't drain the block.

Freeze plug popped, and when he pulled the motor, he found out two things:

1. Popped freeze plug doesn't really protect anything, just means you buy a whole new shortblock.

2. Chevy marine 350's are derived from their racing motors, four-bolt mains, not available in junkyards, and are mucho expensive!

Good luck with it. I hope it's not as serious as it looks.

Dang, that sucks. Did you have it winterized?

I winterized it in November, I did do it differently this time and I think I paid the price for it. I was really short on time this year, so I just got the boat up to operating temp, then switched from the garden hose to a bucket full of antifreeze and ran the engine for about a minute after the antifreeze started coming out the exhaust. I think I ran about 8-10 gallons through it.

Do you think that is failure from freezing? It seems odd to happen that high up in the head if the drain plugs were open. Sucking antifreeze from a bucket is the way I do my Mastercraft as well. My Prostar has a 351.

quote:

Originally posted by sigcrazy7:
Do you think that is failure from freezing? It seems odd to happen that high up in the head if the drain plugs were open. Sucking antifreeze from a bucket is the way I do my Mastercraft as well. My Prostar has a 351.

We had a harsh winter (for NC anyway) and that's the only thing I can think of right now. But I'm like you, I wouldn't have expected it to happen up in the head and to also take such a huge piece of metal out of the head. I'm very interested to get the mechanic's assessment.

I had a cracked block on one of my ski boats about 13 years back. Easy to recall when, because my youngest daughter was a newborn, and sitting in the truck with mom while oldest daughter and I took it out. Water was still cold (late March) and we were trying to get an early start on the season by summerizing it and taking it to the lake for a trial run.

We were in the middle of the lake when it died, nobody in sight, and I ended up getting in and pulling the #@$% thing 1/2 way back to the dock (with rope in my teeth, no less) before getting towed in the rest of the way by a sympathetic sailboat that was passing by.

You know you've been humbled as a ski boat owner when a sailboat tows you in with a trolling motor.

Unless you ruined the rings or damaged the bore from lack of oil, maybe just a new head, like the other poster posted.
Heck if you had to look for a used head, a 350 chevy ought to be the easiest to find and as cheap as you could ask for also.

I always drain the block, plug and fill from the top.

With a boat it is always something.

quote:

Originally posted by KDR:

quote:

Originally posted by sigcrazy7:
Do you think that is failure from freezing? It seems odd to happen that high up in the head if the drain plugs were open. Sucking antifreeze from a bucket is the way I do my Mastercraft as well. My Prostar has a 351.

We had a harsh winter (for NC anyway) and that's the only thing I can think of right now. But I'm like you, I wouldn't have expected it to happen up in the head and to also take such a huge piece of metal out of the head. I'm very interested to get the mechanic's assessment.

If you didn't run it too long with the milkshake in the oil (water in the oil). A new cylinder head would probably fix the problem.

Your issue is really degraded/eroded cylinder head casting from saltwater running through it for so many years and probably not being flushed. A possible lack of antifreeze in there during the winter probably just made the issue that was already there (thin casting), happen sooner. How old are your exhaust manifolds and risers? If they're 7 years or older, change them as they could be leaking into the cylinders as well. You can tell it's erosion by how thin the casting is on the right side (especially) and the left side of the opening/hole how thin the casting now is. The block shouldn't be rebuilt given how thin the cylinder head castings are.

The boat has never seen salt water. I’m the second owner, the first kept it on a small lake southwest of the Raleigh area.

Maybe it was just a flaw that coincidentally surfaced this year, unrelated to how you winterized it. I’ve got a buddy who never winterizes his 350 beyond opening drains and pulling manifold plugs. Here in Utah, there’s no winter that won’t freeze your block, but he’s managed this for 15 years.

Those engines sure take a beating. Running 5,000 rpm for hours on while going from idle to wide open constantly. Perhaps it just got the best of it. Looking at the rust in the crack, it isn’t new. The crack was probably there when you put it away. Maybe water was in the crack, and finally froze and pushed out the weakened piece?

Sorry for your troubles. That sucks. I would like to hear the mechanic’s opinion when you’ve had it assessed.

I read the topic as "Darn boots". I have never heard of that brand. <Hangs head and backs out quietly>

Do you have the chunk that blew off? Maybe a little superglue would fix that up.

Haven't found it yet, but I haven't searched real hard. I suppose I could JB weld it back on and hope for the best.

The local dealer is going to try and work the boat in this week and will get to it no later than next week, which is much faster than I anticipated this time of year. So hopefully, I'll know how bad my wallet will be hit sometime soon.

quote:

Originally posted by KDR:
The boat has never seen salt water. I’m the second owner, the first kept it on a small lake southwest of the Raleigh area.

Given it's never seen saltwater. The rust around the hole indicates the crack has been there a while. It is also a pour (thin casting) as evidenced by how thin the cast iron is on the right side and the left side of the hole, 3 o clock and 9 o clock positions. The thickness at 12 o clock, is the normal wall thickness of a chevy 350 head in that location. A rebuilt head would probably fix the motor.

I originally thought this would be about how those darn boats had all your guns and then sank.

I'm not a boat mech, I did screw around with cars and their parts a lil, but the the amount of rust seems like a long time crack.