#1
IP: 65.198.70.130
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Basic Head Gasket Question
Do head gaskets fail under normal operating conditions or as a result of a specific problem like overheating?
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Tom A |
#2
IP: 38.118.52.41
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Tom,
In over 15 years of using the current Victor steel reinforced graphite head gaskets, we've had so few failures as to have almost no data base of failure modes. I don't recall of a single case of simply failing under "normal operating" conditions, and they are so forgiving of overheating that I can't recall of a single failure for that reason either. The only failure I can think of (offhand) relates to thinness from corrosion in the floor of the head under the thermostat to the extent that it (the floor of the head) actually lifted up off the gasket and allowed gases to escape. When caught early, these gaskets can sometimes be reused. By contrast, prior to the development of the Victor gaskets, we had so many head gasket failures that many folks concluded that the age of the engines had somehow reached a critical point that head gaskets simply wouldn't survive. This tipping point in the life of the Atomic 4, i.e., the availability of serviceable head gaskets, resulted from the work of a single young applications engineer from Victor circa 1992 who heard of our dilemma and designed the gaskets we now use. I promise to research my archives and try to find his name. I can't think of a single event that has meant as much to the longevity of the Atomic 4 fleet. Don |
#3
IP: 65.198.70.130
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Head Gasket
Don,
Thanks for your reply.The engine was rebuilt about 15 yrs ago prior to my ownership and I don't know what kind of gasket was used. I posed the question because last week my nephew had taken the boat out and returning to the dock the engine shut down. He thought it had run out of gas but that wasn't so. Turns out he cranked for awhile trying to get it started. Sure enough by the time I got down to the boat I did some basic testing and found water in the cylinders. Got it running but iit was prety rough. Also, water in the oil. This weekend I'm going to return and do the other items listed in the service manuel, including a compression test. I did the thumb test and it seemed OK. I guess if it turns out my compression is shot and I had an old style gasket it's possible it would fail due to age. We'll see. Tom
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Tom A |
#4
IP: 65.198.70.130
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Don,
Returned to the boat this weekend. Shut off water.Took out the plugs, squirted MMO. Did compression test. #1- 125psi, #2-100, #3- 125, #4- 20psi! Liquid shooting out of #4. Shut-off fuel, removed carb,removed manifold, cranked engine--still some liquid coming out of spark plug hole and exhaust port. (residual water in cooling system?) Where should I start first? Head gasket? Tom
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Tom A |
#5
IP: 38.118.52.41
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Tom,
I don't think your problems are caused by a failed head gasket, but you may as well remove the head anyway as a first step. You never gave any guess as to why the engine shut down for your nephew, but if there was water in evidence in the cylinders from the beginning, the shutdown could have been caused by a small hole opening up in the 4th combustion chamber of the head. Don |
#6
IP: 65.198.70.130
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Don,
I was just assuming that the shutdown was the result of some fuel/carb issue because it happened one other time this season and started up after a few minutes. I guess this time it was water getting into the cylinder and that's why it wouldn't start. If I pull the head will I be able to see the hole in the combustion chamber? If so, what can be done? Tom
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Tom A |
#7
IP: 38.118.52.41
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Tom,
If there is a small hole in the combustion chamber, you'll have no trouble seeing it. If you see a hole in the combustion chamber, you'll have to replace the head. If you can come up with some other explanation for the initial shutdown, we're back to the possibility of the water issue being explained by your nephew simply overcranking the engine with the through-hull open. Don |
#8
IP: 65.198.70.130
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Follow-up to Water Intrusion
Take a look at the head I removed from my engine and ,hopefully, a good one pulled from a "project" A-4. Guess that answers the question of where the water was coming from.
Tom
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Tom A |
#9
IP: 206.230.48.34
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Why, that darn nephew of yours!
> If there is a small hole in the combustion chamber, you'll have no trouble > seeing it. If you see a hole in the combustion chamber, you'll have to > replace the head. Don's instructions do not cover the situation in which there are TWO, LARGE holes in the head. So, I guess you should slap on some duct tape and put the old head back on. |
#10
IP: 38.118.52.41
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Tom:
It does indeed! Don |
#11
IP: 66.161.32.165
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Those are some monsterous holes! Are they due to decay, or ????
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#12
IP: 65.198.70.130
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Hole in the head
As far as cause of the holes, I'll have to leave it to the experts for an explanation. My guess would be age and salt water. I wonder how long it might have been running with at least some water intrusion, assuming that those holes didn't just get that size overnight, or did they?
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Tom A |
#13
IP: 24.185.209.211
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Help
Here's my situation. Took the head off and discovered the holes causing water intrusion. Squirted MMO down cylinders and cranked engine, sprayed PB Blaster and MMO everywhere, covered up engine and went away thinking that while waiting for reconditioned head would clean and adjust valves. Wasn't able to come back for a few weeks and now engine won't crank. Charged batteries and still nothing. Starter engages but won't turn engine. Tried to turn by flywheel, by hand crank, by prop shaft and still won't budge. PLEASE HELP!
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Tom A |
#14
IP: 12.196.53.144
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Tom,
If your engine is not seized too securely, you should be able to get it to start turning by prying against the teeth on the starter ring of the flywheel with a large screwdriver. It will be necessary to remove the starter to access the flywheel from behind. Don |
#15
IP: 70.108.204.58
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Having worked around engines, but never inside them, I am curious. Where do these holes go? I thought the head was solid. No?
Steve |
#16
IP: 71.98.57.64
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water jackets
Steve
The heads and the portion of the block around the cylinders are hollow. This is where the cooling water circulates. Mike |
#17
IP: 24.185.209.211
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Don,
I had removed the flywheel cover and was trying from the front and it wouldn't budge. I tried with a hand crank and still nothing. Very frustrating since is was turning over smoothly and when I left it I squirted and sprayed everywhere. Tom
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Tom A |
#18
IP: 204.145.183.5
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Tom,Using the lower ID of the starter opening as a fulcrum, try prying the teeth of the starter gear with a large screwdriver. If the engine yields, try to get a back and forth movement in the beginning and gradually increase the rotation in each direction.
Don |
#19
IP: 24.185.209.211
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And if it doesn't yield?
Thanks Don. I'll give it a try.
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Tom A |
#20
IP: 204.145.183.5
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If you can't get your engine to turn over, it will have to be removed and disassembled.
Don |
#21
IP: 24.185.209.211
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Thankfully, I got the engine to turn with a really big screwdriver and will now start on cleaning and readjusting the valves.
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Tom A |
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