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Could water ears flood a mercruiser v8 if engine not running ?

I am piecing together a 1997 Sea Ray Express Cruiser 215. It came with no engine or stern drive. I got a 1994 Crown-line with a bad hull, cracked bulging block, but a purportedly good outdrive for FREE. As I disassembled the Crownline for parts, it looked to me like they failed to winterize it and the block froze and cracked. The intake, and water manifolds looked ok. I found a reportedly good mercruiser 5.7 for the right price. I sand blasted, painted, rebuilt carburetor and assembled. The other day was “cross my finders” test day. I had put all new gaskets, thermostat, engine water pump, outdrive water pump and a mess of other new parts. I hooked up the water ears and started it up. It fired up immediately and ran great at about 700 rpm. I revved up to 1500-2000 a few seconds a couple times just to see how it sounded. It sounded great. After everything seemed to warm up (maybe ten mins mostly at idle), I shut it down. Now the oil pressure sender was working and op was great. Voltmeter seemed low and temp had no reading at all. I have to investigate wiring. Likely a bad connection. Anyway, back on point. While it was off, I checked the oil. It looked great. Brand new still and right where it should be on the stick. I started it up again, and ran at idle for about 20 minutes and this time I brought it to about 1800 RPMs for about a minute possibly two. I KNOW YOU AREN'T SUPPOSED TO RUN ABOVE IDLE ON MUFFS. I was paying close attention to how hot the water manifolds were. I needed some assurances before I dragged it to the lake for further testing. AND IM GLAD I DID! After a minute or possible two, the orange alternator wire stated getting very hot and melted the single layer of electrical tape I had wrapped around the alternator bundle! I killed the engine and began investigating. All the while the ear muffs were still connected and water still running. I ended up pulling the alternator out and disconnecting the wiring and checking all the wires for short to ground or bad connections. I didn’t expect any as I am an electrician and had gone through all of this already. Battery cables are HUGE and mint. One new battery one 2 1/2 years old that took a charge ok. I took the alternator apart and everything looked ok inside too. It was newer when I took it off the other boat. I am wondering if possibly the field and sense wires got mixed up since they were both the same plug (wish they made them opposite connections so it couldn’t get mixed up). Anyway, too much time gone by and had to pack it in for the night. Got out of the boat shut the water ears off. Put the boat away. Got in the boat this am. Put the alternator back together. Reconnected the wiring being sure to have the purple on field and the purple red on S per the mercruiser manual. My plan was to run the boat and check voltage at varying points. My problem with the wire seemed rpm related so suspect voltage regulator failure. Was going to investigate voltage at different RPMs. Also was going to put the Amp clamp on orange wire and see what kind of amperage was coming out. Never got that far. Hooked up water ears. Got in the boat. Had fully charged batteries. Cranked over and it sputtered and coughed but did not start. I tried a few more times - wanted to catch but wouldn’t run. I thought - hmm “ I only put like 3 gallons in an empty 50 gallon tank. I did run it a few times yesterday with the last run at higher RPMs for a couple minutes. So I went and got five gallons of gas. Put it in turned water ears on and tried again. This time after a few cranks it started to slow and get hard cranking. I figured batteries took a hit. I hit the battery disconnect switch and began charging them up. All the while the water ears running. After a half an hour, I tried again. This time a couple cranks in and it didn’t want to crank. Now I was worried. I pulled plugs and disconnected and grounded coil lead. I cranked over and water came spouting out spark plug holes all over. Seemingly all of them though I couldn’t watch every cylinder at once. OKAY THAT WAS A LONG STORY TO GET TO MY QUESTION. Can water ears left running with the engine off flood a motor? I mean they may have run for 2-3 hours between yesterday and today before I started trying to crank it. I know you can’t do that on Seadoos. It’s start first then turn on water. Shut off water then shut off motor. My experience has always been the opposite on boats. Water first then motor on. Motor off then water off. It didn’t occur to me that extended pressurized water could possibly get into the motor if the motor wasn’t running. I figured you needed the engine water pump to complete the circulation before any would be up in the motor. IS THIS POSSIBLE? I sure hope it is! I would rather be called an idiot or lazy for not shutting off the water than to have some other problem like a cracked head, intake, or water manifold that I just didn’t see previously. I blew all the water out of the cylinders by cranking a bunch of times with coil lead grounded. I don’t see any on the dipstick. If this is all just getting into the cylinders through the water manifolds and open exhaust valves or something, then I will just run it again (CAREFULLY CONTROLLING THE WATER SUPPLY!) and probably change the oil just for good measure. I still need to investigate my over-amperage situation, but it seems a minute problem in comparison now. I might as well ask. If the sense and field wires were reversed, could that have caused my over heating orange wire? I don’t think they were reversed, but I paid more attention putting together than taking apart. I didn’t see anything else wrong. I had planned to isolate older battery to see if it were causing excessive draw. REALLY I WANT TO KNOW IF THE MUFFS COULD FLOOD THE MOTOR!
 
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Ayuh,..... If you want any answers,..... Learn to use paragraphs,......

No way in f*^kin' 'ell, I'm gonna wade through that word soup,......
 
It’s come to my attention that I said too much. People LOVE to pick apart what you do or say there is not enough info provided. Try to head that off with all the info and you talk too much. Here the question short and sweet. Can ear muffs left on with running water but not running engine (for hours) flood a motor?
 
Ayuh,..... If you want any answers,..... Learn to use paragraphs,......

No way in f*^kin' 'ell, I'm gonna wade through that word soup,......

I have to agree with Bill. Organizing thoughts and using paragraphs makes a person's comments/questions much easier to read.


So on to your question short and sweet:

By design, the garden hose water muffs will leak off pressure/volume around the stern drive's inlet.
If the seawater pump impeller is a good tight fit, no water should get past it while the engine is not operating.

However, if the seawater pump impeller is not a good tight fit (as in old and/or worn badly), it may be possible for garden hose water to get past it.
And if the water supply is left running for hours (as you asked about) it may be even more possible.


As for running above idle speed while on the garden hose muffs, that is typically a disclaimer by the OEM.
For example;
On the hard, we must always operate an engine above idle speed when checking the ignition total advance.
This involves reaching up to 3,500 RPM or so!
We just don't hold it there for any long duration.





By the way, technically speaking, there is no "ground" on a 12 vdc system... only Positive and Negative.
Ground refers to Earth Ground as with AC current.



.
 
as mentioned by two of the three posts above no wont fill engine with water.

Did you reuse the exahust manifolds and elbows off the cracked engine ?
 
It’s come to my attention that I said too much. People LOVE to pick apart what you do or say there is not enough info provided. Try to head that off with all the info and you talk too much. Here the question short and sweet. Can ear muffs left on with running water but not running engine (for hours) flood a motor?

No....Bondo did not suggest your said too much...
 
Hey everyone. Thanks for your replies. I’m sorry about the format of my original post. I was super frustrated and trying to get all of my thoughts down. I was just trying to make the point that I had no known connection or history with any of the parts - boat included. I had no way of knowing if anything was good. The motor I bought had good compression. It was supposed to be nearly new. Boat came with no engine or outdrive. Outdrive donor boat had a cracked block. I DID REUSE THE MANIFOLDS. A manifold kit is like 8-900 bucks. This boat is a flip. Not keeping it. I reused what I could. I did buy all new gaskets, water pump, battery, outdrive impeller kit, plugs, cap, rotor, wires and thermostat. Reused hoses, water manifolds, and intake and carb from the donor boat. Rebuilt carb. I am a decent mechanic, but only have limited boat experience. It ran great on idle two different times for nearly an hour between the two. I had shut it down and started it two or three times. It revved fine and ran great at two grand as well. When the alternator wire heated up after about 1-2 minutes at 2000 rpm - I shut it down. After that, the next day was when I had the water intrusion . It never restarted. I haven’t looked at it since - Holiday busy. My next plan is to do a compression check. No water on the dipstick. I was pretty freaked, but it seemed like water came out of every spark plug hole! If it was a water manifold or riser, wouldn’t it just be one side? I asked about the hose fill up because I remember reading something about Volvo Penta making taller risers due to some kind of water intrusion situation. Again, I’d like to think I’m a smart guy. I have a decent vocabulary, went to private school and college, but the written word with paragraphs and syntax is just not my forte. I am a technician electrician by trade with a minor in mechanics. I have rebuilt from the frame up several engines, transmissions, rear ends and have done welding/fabrication and some fiberglass work for a body shop. I just didn’t grow up at a marina so I am bowing to your more experienced knowledge. I worked in auto parts for thirteen years before becoming an electrician. Some of the best diagnostics is polling an audience and seeing what common failures are. How do I get water in every cylinder seemingly all at once when I wasn’t even running?
THANKS! Please don’t give up on me because I am long winded.
 
I also just remembered - the donor boat guy indicated that it had run the season before but was not winterized properly. I probably shouldn’t have reused the manifolds, but I had a whole pile of unknown parts and had to trust in some things - or I would have been buying ALL new parts for a 1997 boat. It amazes me how you can buy two or three used boats for what it would cost you to build one from new parts. 900$ for a manifold/riser/gasket and bolt kit. I paid a grand for the boat. The donor boat (which did have a good Alpha one gen two drive at least and hopefully SOME other good parts - was free. The replacement MERCRUISER 5.7 was like 300 bucks. It was bought by a hot rod maker I sort of know. After it was installed in a 55 Chevy the owner changed his mind and decided he wanted the LS6 engine and paid up for it. This guy always used merc engines in the cars he built. Could the water be in all the cylinders if the intake were at fault? That came from the donor motor as well.
 
I dont thinnk intake would do it but exhaust manifolds as mentioned can you can pressure check or check with acetone as it wicks into cracks better than water. If it was off a cracked engine I would have reccomended tossing them too much risk in my opinion, but you can check them.

You said this engine was in a 55 chevy? Did he swap the cam from the mercruiser OEM cam ? There is a big difference in overlap on cams used in boats (truck applications are very similar and considered interchangable) and rtypical hot rod cams. If it has even a mild street car cam you can get reversion and pull water in the exhaust valves.
 
Hey everyone. Thanks for your replies. I’m sorry about the format of my original post. I was super frustrated and trying to get all of my thoughts down. I was just trying to make the point that I had no known connection or history with any of the parts - boat included. I had no way of knowing if anything was good. The motor I bought had good compression. It was supposed to be nearly new. Boat came with no engine or outdrive. Outdrive donor boat had a cracked block. I DID REUSE THE MANIFOLDS. A manifold kit is like 8-900 bucks. This boat is a flip. Not keeping it. I reused what I could. I did buy all new gaskets, water pump, battery, outdrive impeller kit, plugs, cap, rotor, wires and thermostat. Reused hoses, water manifolds, and intake and carb from the donor boat. Rebuilt carb. I am a decent mechanic, but only have limited boat experience. It ran great on idle two different times for nearly an hour between the two. I had shut it down and started it two or three times. It revved fine and ran great at two grand as well. When the alternator wire heated up after about 1-2 minutes at 2000 rpm - I shut it down. After that, the next day was when I had the water intrusion . It never restarted. I haven’t looked at it since - Holiday busy. My next plan is to do a compression check. No water on the dipstick. I was pretty freaked, but it seemed like water came out of every spark plug hole! If it was a water manifold or riser, wouldn’t it just be one side? I asked about the hose fill up because I remember reading something about Volvo Penta making taller risers due to some kind of water intrusion situation. Again, I’d like to think I’m a smart guy. I have a decent vocabulary, went to private school and college, but the written word with paragraphs and syntax is just not my forte. I am a technician electrician by trade with a minor in mechanics. I have rebuilt from the frame up several engines, transmissions, rear ends and have done welding/fabrication and some fiberglass work for a body shop. I just didn’t grow up at a marina so I am bowing to your more experienced knowledge. I worked in auto parts for thirteen years before becoming an electrician. Some of the best diagnostics is polling an audience and seeing what common failures are. How do I get water in every cylinder seemingly all at once when I wasn’t even running?
THANKS! Please don’t give up on me because I am long winded. I also just remembered - the donor boat guy indicated that it had run the season before but was not winterized properly. I probably shouldn’t have reused the manifolds, but I had a whole pile of unknown parts and had to trust in some things - or I would have been buying ALL new parts for a 1997 boat. It amazes me how you can buy two or three used boats for what it would cost you to build one from new parts. 900$ for a manifold/riser/gasket and bolt kit. I paid a grand for the boat. The donor boat (which did have a good Alpha one gen two drive at least and hopefully SOME other good parts - was free. The replacement MERCRUISER 5.7 was like 300 bucks. It was bought by a hot rod maker I sort of know. After it was installed in a 55 Chevy the owner changed his mind and decided he wanted the LS6 engine and paid up for it. This guy always used merc engines in the cars he built. Could the water be in all the cylinders if the intake were at fault? That came from the donor motor as well.

HOLEY MOLEY,..... Have you ever heard of a Paragraph,..??..??

It ain't how much yer sayin', it the lack of paragraphs that make yer posts, Unreadable,.....
 
I will have to try and follow up with him about the cam. I remember him saying he bought mercruiser crate motors because of the way they did the intake ports on the heads. He wasn’t building race cars. Just nice reliable stuff with a little rip. I remember him saying they are like 300hp out of the box.
 
Update - I connected my compression tester extension hose and cranked over each time before connecting the gauge. The narrow outlet raised pressure in the cylinder and forced any remaining water out. I didn’t write down which cylinders, but water came out of most of them (just mist mostly now). Compression still good (around 150 +/- a few pounds) and held. Engine wasn’t running when the water problem revealed itself.
Still doesn’t show any water intrusion on the stick.
Looks like BOTH water manifolds/risers must have cracks? I wonder if it could have been seeping in even while running, but at a low enough rate that it just got purged out exhaust. Maybe from sitting with hose on, but no back pressure from exhaust they filled up?
How do you like THOSE paragraphs? Ayuh!
I am going to take a creative writing course just so I can post on this forum!
 
Neither was vortex.
It’s starting to look like there were some internal cracks on BOTH exhaust manifolds/risers. The water entered the cylinders when the boat was connected to a running hose for extended time without the engine running. If any were getting in there while it was running, it was getting purged with the exhaust.
I did a controlled experiment today. I made sure all water was out of the cylinders. Got in the boat, turned on the water and started it immediately. I ran at idle and accelerated as high as two thousand rpms for a couple seconds. Total run time maybe three minutes. Shut down water immediately after shutting down engine (hose valve shut off inline draped over the hull).
Everything sounded fine. Going to replace both manifolds and risers.
 
.... not to be picky, but they're called (exhaust) elbows.... some engines have elbows AND risers, so the distinction is not trivial. There are gaskets between the manifold and elbows. There can be as many as three different type of gaskets depending on the application.... use the correct ones.
 
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Sorry to bother such an old thread, but I graduated in physics and did some quality college and university studies, however I can't answer this simple question. Now, I am helping my younger brother to prepare for his research work and his topic has tangencies with the thread's topic. Therefore, I bet that here I can find the answer if anyone is still alive. I could buy term papers, but I want to give a try. So please give some indications and support - what is the conclusion about the boat and water flood in terms of some rules of physics when such cases happen and when not. Thanks in advance for considering my question*
 
Sorry to bother such an old thread, but I graduated in physics and did some quality college and university studies, however I can't answer this simple question. Now, I am helping my younger brother to prepare for his research work and his topic has tangencies with the thread's topic. Therefore, I bet that here I can find the answer if anyone is still alive. I could buy term papers, but I want to give a try. So please give some indications and support - what is the conclusion about the boat and water flood in terms of some rules of physics when such cases happen and when not. Thanks in advance for considering my question*

Ayuh,..... Not sure what yer askin' here, but proper boat exhaust doesn't drop the water into the exhaust system, til after it's well beyond where it could flow back into the motor's cylinders,.....
 
Sorry to bother such an old thread, but I graduated in physics and did some quality college and university studies, however I can't answer this simple question. Now, I am helping my younger brother to prepare for his research work and his topic has tangencies with the thread's topic. Therefore, I bet that here I can find the answer if anyone is still alive. I could buy term papers, but I want to give a try. So please give some indications and support - what is the conclusion about the boat and water flood in terms of some rules of physics when such cases happen and when not. Thanks in advance for considering my question*
I can't definitively understand your question but I bet you mean the exhaust system of the boat and in what cases does it fail or what?
 
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