Stupid engine rebuild

[wotan2525]

I'm just trying to spit-ball here but on my rebuild, there were different headgaskets available and some of them had some cooling ports blocked off. Are you certain that you used the correct ones?

[TitanTn]

I'm just trying to spit-ball here but on my rebuild, there were different headgaskets available and some of them had some cooling ports blocked off. Are you certain that you used the correct ones?

Great question, and no, I'm not 100% positive, but I tried to watch that as I was assembling. But with 22 hours on the rebuild, I've not had once instance of overheating even slightly. I would think I'd see the temp rise and lower slightly with the opening and closing of the thermostat if it were fluctuating.

I actually just got back from the machine shop and I think they figured it out. It's simple, so I'm embarrassed to say it hadn't occurred to me. I've let the issue of all 8 cylinders being full of water to make me think it's not exhaust manifolds or head gaskets because why would both sides fail at once? But actually the intake manifold is just a pass through from one side to the other. So if an exhaust manifold failed, it would fill up the pistons on both sides of the engine. So I very likely had an exhaust manifold fail and it filled all 8 cylinders with water. So now I'm going to pull the manifolds and do some testing. But I really think this is it.

[CJD]

Interesting. Exhaust was the only thing I could think of, but I agreed with everyone else about the low chance of both sides failing. What you say makes sense, though.

[supraaddict]

There are no dumb questions. Just a dumb boat that I'm sick of wrenching on. No, I didn't do anything different with the exhaust. The manifolds are somewhere around 6 years old I'm guessing. The previous owner bought them, so I don't know exactly.

The reason I asked the question is in your OP you stated that you were motoring on the lake just fine and when you shut the engine off it wouldn't restart because the cylinders were full of water. The only time this ever happened to me was when a hose came off for the main water inlet on my engine and my engine temp started rising rapidly, I instantly grabbed the throttle and shut her down. I reattached the hose, let the temp come down to 130 and tried to start her back up. The engine wouldn't crank and same thing... water in the front cylinders. Had the boat towed, got her on the trailer, pulled her out of the water and instantly noticed that the exhaust flaps were melted off. So obviously when the temp started rising and l pulled off the throttle and shut off the key, there were no exhaust flaps to hold back the water and in turn filled the cylinders up with water. Pulled all the plugs cranked her over and over, fogged the cylinders, replaced plugs and wires and she started right up. Compression test good and let her run for about 45 minutes to ensure that the cylinder walls did not rust. Everything seems to be good now (Replaced the Exhaust Flaps as well). Might not be your issue but just trying to give you other possibilities in case something may have changed on your boat.

[TitanTn]

Thanks Brad. Unfortunately I don't have flaps, I have supertrapps, so I don't think this could happen to me. I had been idling for about a minute before I turned it off, so there was no opportunity for water to come back anyway.

I pulled the exhaust manifolds off tonight. I hooked a hose to the water inlet side and turned it on. Water filled the manifold jackets and came out the exhaust side as expected. Nothing leaked back into the exhaust gases side. Did I not test this right? Is it possible that it'll leak badly when it's hot, but not when cold? I'm so disappointed that the issue wasn't obvious. Anyone ever make a tool to remove the riser from the manifold? What now?

[TitanTn]

Based on this article - http://www.boatus.com/seaworthy/swbtob.asp

I think it could still be the manifolds. I don't know how old they are, and I've had the boat for 4 years. Even if they're not completely at fault, I will likely need to change them soon anyway. I think I'm going to bite the bullet and replace the manifolds and risers now. I'll be sick if that doesn't fix it, but I just don't know what else it could be.

[ssa]

Just a heads up if you do end up getting new manifolds. Whatever it is PCM paints theirs with isnt high temp resistant. I replaced mine this spring and when I took it out for the first time to check everything out since I'd had all the running gear out of it over the winter I got a nice surprise. About 5 minutes out of the no wake zone I could smell something burning. I started looking around and couldn't see anything around the lake it was coming from and thought theres not anything in the front of the boat to catch fire and if its coming from behind me and I'm smelling it running 30 this isnt good. So I stop open the engine cover and smoke is rolling out. My little girl says are we going to sink right here in the middle of the lake. Lol. Anyways it was burning the paint off the runners before they enter the water cooled section. Took about 30 min before it all came off. I'd ran it about a hour in the driveway without it affecting it.

[TitanTn]

So I spoke with Vince from skidim.com today and I was fully ready to purchase some manifolds. For those that don't know, Vince is a master at inboard ski boats and is a tremendous resource for us. Based on the water being in all 8 cylinders and that the manifolds passed my test, he's convinced that the manifolds aren't the problem. We went through many different scenarios and couldn't come up with anything plausible. His final recommendation was to reassemble everything and do some testing on the hose, and then at the lake. So I've got everything reassembled as of tonight.

I just don't see how both banks of cylinders could get water without it being some kind of ingestion/sucking water up the risers. If so, what caused it? I have no idea. So this is where I am. No where new. I'll be testing on the hose tomorrow afternoon and go from there.

[inair]

Hey Rob how are you doing with this? Any headway?

[Zim]

Did you recently fill up your boat with fuel? Could be water in the gas...