SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: whiteamericanfab on April 05, 2008, 09:41:30 PM
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I just recently got a boat with a 455 olds motor in it.I got the boat for a really good deal so i figured i would rebiuld the motor and stuff and fix a few things be ready for this season but theres water in the oil and it scored some things up.so i got my unckles 455 marine olds and tore it down to use the block for a rebiuld and theres Alot of watre in the oil its still stock but the other one is .30 over already i was told olds have alot of problems with this.does any one have any suggestions on trying something else out on them? there was no blown head gaskets nothing i checked this thing out pretty good and cant figure it out.does any one have a water diagram i could look at for these things or what?
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It is funny you should post this topic- we just got back from the lake and a close friend is having the exact same issues with his 455 oldsmabubble- He just got the motor back from 2 very well known and renowned motor builders and they are both claiming that it has to do with the exhaust- logs- something to the effect of it sloshing back through the exhuast and down the cylinders into the oil- I call Bull Sh*t!!! what kind of exhuast are you running???
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both motors i have where running through the hull and i believe they call them logs not exactly sure on termonolgy on them.with some trumpet tips out the back and no flaps i was told the flaps are a must on these motors also.
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It is funny you should post this topic- we just got back from the lake and a close friend is having the exact same issues with his 455 oldsmabubble- He just got the motor back from 2 very well known and renowned motor builders and they are both claiming that it has to do with the exhaust- logs- something to the effect of it sloshing back through the exhuast and down the cylinders into the oil- I call Bull Sh*t!!! what kind of exhuast are you running???
I run logs and snails on my motor and have never had any water in the oil so im calling bullshit on those engine builders too!!! >:D
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That is what I thought- if you get water flowing back up the exhuast, it should hydro?, not dump a cup of water into the oil pan- :sly:
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There are a lot of different reasons why you would have water in your oil.
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Most through transom exhausts need a rubber flapper on the exhaust outlet, but like factory502 said I would expect the engine to hydrolock rather than keep running.
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Do a leak down test on water system block out let apply air see where it leaks or holds pressure that will separate the bull shit from the water . :banghead: ten to one it is reverson, no flaps,and no water shut down control. ::)
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... ten to one it is reverson, no flaps, and no water shut down control. ::)
Ten to one? Hmmm... that's pretty good odds...
I'd rather take a different bet, ten to one he's supposed to have flaps on the exhaust outlets. :D
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If you are sucking just a little water in, esp if the rings are worn, the motor may not hydrolock. It will only do that if there is more uncompressible liquid than air. You also don't know how long it took for the oil to get that way - it may have been an entire season or two.
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Here's my 2 cents. Could it be that there's too much water pressure in the exhaust logs and the manifold gaskets are blown and water is getting into the cylinders and since there is pressure the water is escaping up through one of the valves as it opens or closes... Letting the water to drain with the oil into the pan? Or another thought, how about a blown head gasket?
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How to check for water in oil , If you don have and air compressor ,you can use your water hose connect it to motor block off out let. Drain oil leave plug out of pan turn water on it should have a 75=100 lbs pressure on it let it set with water pressure for a while . If water come out you got problem fix and repair no water no bull shit, have also seen logs
leak in side, If you have a push button starter separate from your ING off you can crank motor over when you pull boat from water motor wont start and motor should plow most water out.
of logs or ex runners. And you can turn motor over when you are going to start it after it has sat for while, boat motors set some times for a long while this way you don't start motor dry. Turn motor over several times be for you start it :o
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For the issue we are dealing with- this is a new motor, it was built the end of last season and noticed water in the oil. Chalk that one up to new ring not seated???? take it back to builder A- log gasket no good- replace, retry. No water in oil. Winner- this season first trip, no water, second trip water. F builder A- So now he goes to builder B- says that exhuast outlets to high and water is being trapped- lowers the outlets, next trip no water. Next trip- water- calls builder B- "check your flaps", no good new flaps- no water, next trip water- :banghead: :mad: :banghead:
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INTAKE MANIFOLD GASKET!!!!
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Elwood, you probably have more experiance than I do with water pressure, but I would be worried that 75-100 lbs is too much. Cylinder pressures reach far more than that, so maybe it's OK, but I always assumed 30 lbs was a safe maximum to avoid blowing out a head gasket.
I know if I find out I can safely do 40 + lbs I will be really happy, becuase I have a 40 psi preset water regulator so it is a simple plumbing job.
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That was my next thought-
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intake manifold gasket was what I ment- how much pressure does a pump push through the motor???
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When my ford was having the same problem , that's what it ended up being the problem. Changed out the intake manifold gasket and put gasket sealer around the water holes on both sides of the gasket and have never had a problem since!
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The pressure regulation in a car is done by the radiator cap, and those typically go to 25lbs max, with 15-17 being the norm. However, maybe it's regulated to that due to the hoses, radiator, pump, or something other than the block sealing (which is the only thing we are dealing with in a jet boat without a water pump). I don't know. Cylinder pressures are 10X+ what the radiator cap would regulate it to, so maybe it isn't an issue. It would be good to know.
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Couple of things to remember regarding the Olds. First, DO NOT use the stock tin "turkey-tray" intake gasket. They don't seal well with aluminum manifolds. Use a normal style(composition) gasket from Mr.Gasket(two styles available). I think FelPro may also make one.
Second, after decades of use and corrosion, the timing covers and water pump block off plates are a possible source of water entry to the crankcase. Take a good look at both items before making the "assumption" that it is caused by reversion in exhaust or bad head gaskets.
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Well im to the piont to wear i tore both my motors down to the block still havent taken out pistons and all that good stuff but im right there getting ready.niether motor had a bad head gasket both run logs and snails 1 had rubber flaps the other motor didnt the 1 with the flaps had alot more water so it couldnt be that the motor with flaps had a bad manifold gasket though and the previouse owner used silicone only. i havent checked the front plates yet on the block i guess that will be next and then im going to try and find a leaks in the logs i have both sets to full motors so if any one needs olds parts let me know.willing to trade also.
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... the previouse owner used silicone only...
That can do it alone.
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That can do it alone.
You got that right. It's too bad they think because using silicon on a race motor that gets pulled apart between races it'll be ok on a motor that is just going to run. Ya gotta have those gaskets in there, otherwise they wouldn't make 'em. :D
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That can do it alone.
Using silicone on, or instead of, exhaust manifold gaskets wont cause a reversion problem.(unless you run the boat UNDERWATER)
Both Ford and Chevy produced V-8s that used no exhaust manifold gaskets. Just relied on properly machined surfaces to seal.
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Using silicone on, or instead of, exhaust manifold gaskets wont cause a reversion problem.(unless you run the boat UNDERWATER)
Both Ford and Chevy produced V-8s that used no exhaust manifold gaskets. Just relied on properly machined surfaces to seal.
Looks like I missed something on this thread, I thought I read the previous owner used only silicone for the intake manifold gasket. Sorry.
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Looks like I missed something on this thread, I thought I read the previous owner used only silicone for the intake manifold gasket. Sorry.
Me too, but then going back I don't know where the silicon was used for sure.
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Since he was talking about the different logs, I assumed that was where the silicone was. I can't imagine anyone using silicone by itself for intake gaskets. :o That would definitely be a problem.
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Do the front plates that convert the water around have o rings in them or gaskets or hows that work do those rought out often? or is it common for logs and snails to go bad?
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Last season, I hydrolocked a couple of times. Trying to figure it out, drove me out of my mind. Got a ton of great direction, from the forum. Turned out, after all the bullshat, it was the inner flappers in the thru-hull exhaust tip. 2 minutes and $10 bucks fixed the problem. That cheap, I plan to replace them every year. Just my .2 cents.
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Since he was talking about the different logs, I assumed that was where the silicone was. I can't imagine anyone using silicone by itself for intake gaskets. :o That would definitely be a problem.
I had bought a Rogers with a Olds 455 (water in oil) that has only silicone for the intake gaskets and then I read this and assumed... :banghead: But I'm pretty sure now that he meant on the logs which wouldn't be a problem. :banghead:
Do the front plates that convert the water around have o rings in them or gaskets or hows that work do those rought out often? or is it common for logs and snails to go bad?
With the water inlets and outlets that I've seen it's usually just gaskets. Most of these parts are getting pretty old and will sometimes require silicone. The only broken logs/snails I've ever seen are ones that I tried to take apart. :banghead: (will trade for 1 Coors Light).
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(will trade for 1 Coors Light).
I've got some filtered water I can add food coloring to, will that do? It's almost the same thing. Might get the dog to add a little flavoring for you. ;D ;D ;D >:D >:D >:D :-*