Water in the heads!

Got a problem. Needs some help! Put my 69 Mustang 302 back in the water first time today. Ran great. 2 hrs run time, fast, slow, cruise, shut it off 1/2 doz times fired back up no problems at all. Got back to the dock. Let her sit for an hour, went back for a late ride, hard to start, ran rough for a few seconds then shut off hard. Tried to start back and would hardly spin at all. After trying several batteries realized it was internal; pulled each exhaust off and water poured out. Pull the plugs, spun it over and water shot out, but no water in the the fresh, one-day oil, so whatever happened had to have just happened. Stuck the plugs back in, spun her over and she fired right up. Put the exh's back on and idled fine for a few minutes, but after driving up the trailer she just cut off. Hit the switch and she wouldn't turn over. Pulled her out of the water and once again water, but only a small amount in the exh's. But now there's a little water in the oil, which doesn't surprise me since the cylinders were full. I tested the exh's and no water came in thru the ports. There was water in both heads. Please give me ideas. Never had this problem before. Thanks.       

Wow. Since water appears in both exhausts, I would look at valve timing. This is just a guess. Something has to be sucking the water up the tail pipes.

Unless you are making steam from a water leak somewhere at the cylinder intakes and the steam is condensing and accumulating in the exhaust manifolds. If this is the case I would look at your intake manifold. Check all of the bolts for tightness before you rip it off.

I had a car once that skipped a link on the timing chain. The car ran smooth and had strong low-end torque. Smooth operation went to heck at higher RPMS though. If I had never ran at higher RPMs I might not ever suspected anything was wrong.

If the exhaust valves close too late might the engine suck water up into the exhausts where it later found its way into the cylinders? I dunno.

Just an idea.

I agree with 79. Look the the exhaust manifolds first. (Although it is strange that it happend "all-of-a-sudden").

You have my sympathy.

Let us know what you find.

Did it freeze where you live? The exhaust manifolds or risers (or something else)may have froze & cracked if you did'nt drain them. You say you've tested them but they may not leak until hot. I would not crank it over or start it without knowing where the water came in from or you may bend a rod, bust a piston or screw up the valve train. My $$ is the exhaust is the culprit......

Let's see. The exhs were taken off completely for painting prior to winter and winterization, as it does indeed freeze in NC. As for the intake, it's got me scratchin my head right now. It's an Edelbrock with no rear water crossover so only #'s 1 and 5 get directly affected, right?. But would it have to crack on both sides to dump water to both banks? I'm aware as to how it could then enter the exh's and make it to the remaining cylinders. I'll quit my mind-numbing speculating as the intake is coming off tomorrow or Wed, and I'll post the results. Thanks for the input.

Does your boat have exhaust flaps?

Reid, have you had time to identify the problem?