engine valve problems

Sometimes you luck out. I pulled all the plugs on the port engine; the cylinders are emmpty. It's not hydrolocked. The starter relay or the starter itself is bad! I put the plugs back in and spent some time cleaning the cockpit from of the dirt, oil, and stains I left while working on the engines. Sometime over the winter I'll pull the starter relay and the starter and check which one needs replacement. Luckily this starter is actually easy to pull; it's right on top. That's probably the easiest part to pull on this entire engine. For now, I'm going to take a shower and relax a bit.

By the way, the engines are fresh-water cooled engines with auto antifreeze mixture running through the blocks and heads. The only sections which get seawater are the exhaust systems and the heat exchangers. There never was any seawater in the blocks or heads. I'm still thinking that the exhaust manifolds may have small cracks in them. I may pull all four again over the winter and have them tested for leaks. I don't want to begin next season with the same problems I had this season. We were seriously considering selling the boat because my wife is retiring in two weeks and we may be moving. The expense of the boat may be more than we can carry. However, my wife is now leaning towards keeping the boat because we'll have more time to use it now that she won't be working. We'll see what happens in the spring.

Meanwhile, I just want to wish you all a Merry Christmas, Happy Chanukah, and a healthy and happy New Year. Hy
 
long thread,

from what is described there is water entering the exhaust side. there are 3 possibilities and fairly easy to sort out which are contributors; fresh water, raw water loop & regurgitation from the exhaust stream. to eliminate the first two; use a radiator cap tester on the fresh water side and see if it holds pressure. close the raw water intake and seal the dripless bearing feed, remove the raw water feed at the riser and install a test cap, pressurize and see if it holds. if you eliminate the first two then regurgitation from the exhaust stream is the issue. big block 454's have a long history of vibrating water uphill in the exhaust stream particularly when the riser is not high enough above the water line/discharge height. there are specific design requirements for the number of inches of fall required to keep water out of the exhaust stream. if you find yourself on the third, it is best to get an exhaust system specialist involved as its not easy to specify this without knowing specific measurements on your specific application.
 
Thanks, Vic. I know the fresh water side is fine, so I can eliminate that. I'll do the pressure testing on the raw water side. It's much easier and cheaper than pulling the four manifolds and bringing them to the engine machine shop to test. He had actually tested one of the manifolds by placing it on a rubber, oil-saturated pad, placing a suction line with a second, smaller pad on the outflow side, creating a vacuum with a pump connected to the smaller pad, and seeing if the vacuum held. It did. Ironically, that was the manifold from the head which failed twice. These engines ran perfectly from 1997 to 2012. Only when I started them in 2014 did they have prblems. Hy
 
Vic, I used to pressure-test cooling systems decades ago when I was a mechanic. At first reading, your suggestion for testing sounds good. However, I'm doing some mental imaging and am having a problem with your testing recommendation.The raw water feeds are at the bottoms of each exhaust manifold. Raw water flows within the outer shell of each manifold, cooling it and the riser spacer. It then flows up the inner shell of the riser and out the end, meeting the exhaust gases and flowing to the muffler and thru-hull exhaust. To pressure test the manifold, I would have to remove the feed hose and connect a radiator hose and fitting, as you suggested, connecting a pressuring pump and guage. Wouldn't I also have to remove the riser and cap the connection with a flat plate and gasket? Otherwise, as I see it, the manifold would never pressurize because the riser end is open to the exhaust. Hy
 
Hy, now as you mention it. It made me wonder the way your mechanic sealed the manifold. I'm a little vauge on how it was done and was thinking what he was doing was sealing the outer casting which could only tell you if the outer casting was intact...in other words, how was the exhaust end sealed?
 
The machinist lay the manifold 'face' (the side which is attached to the head) down on an oil-soaked rubber pad. That sealed that side of the manifold. He had a set of square and rectangular rubber pads to fit various inner cores of manifolds. He found the one which sealed the rectangular outflow section of the manifold. The back of this pad had a male hose connector on it, like the one for an air hose. This was connected to a vacuum pump. When activated, the vacuum pump sealed the manifold ends. The pump was turned off and the guage read the vacuum present. If it held for 5 minutes, all was well. This was a setup manufactured to test exhaust manifolds; it was not a 'home-made' device. So I know that that mnaifold is OK. I need to test the other three.

If I pull a riser and inset a flat plate between the riser and the spacer, I can then test the manifold and spacer inner cores for leakage. That would tell me if any raw water could be leaking into the inner part of the manifold or spacer because of an inner crack. That would be less work than pulling each of the manifolds themselves. I would have to buy a bunch of riser gaskets, two for each manifold, doubled because of testing and re-assembly, a total of 16 gaskets! At ten bucks a gasket, that quickly adds up. I could try re-using the present gaskets for the testing ans see what happens. Either way, that's a project for sometime next month. Right now, the boat's supposedly being shrinkwrapped today. I have to go back to the marina to remove the TV and to put the linens into vacuum-sealed bags for the winter. I'll do that either tomorrow or Monday, depending on the weather. Have a good weekend, all. Hy
 
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