Diagram for coolant system?

DiLevan

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May 8, 2022
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I bought the boat with a Chevy 350/5.7 vortec in pieces. Reassembling from long block up. Can someone help?
 

Bondo

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Ayuh,..... Welcome Aboard,.... Mercruiser,..??
Volvo,..??
OMC,..??
'bout what year,..??
Carbed,..??
Efi,..??
Mpi,..??
 

Buster53

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Jun 16, 2022
Messages
34
Ayuh,..... Welcome Aboard,.... Mercruiser,..??
Volvo,..??
OMC,..??
'bout what year,..??
Carbed,..??
Efi,..??
Mpi,..??
Most important question…Fresh water cooled or raw water cooled
 

alldodge

Supreme Mariner
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Mar 8, 2009
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Serial numbers are best, but if you have the 6 port thermostat housing then this would be it for open cool

6 port T stat housing.jpg
 

alldodge

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0C6050603 is original motor serial #. R&R back OEM 5.7 vortec
Have to many digits to the right of the C
If its 0C605603 then it can have 1 of 2 different thermostats. The one above in previous pic and one other, you tell us
 

Buster53

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Not sure. I think fresh water? How can I tell? There is no radiator, I do know that.
Fresh water cooled engines do not have radiators…they have heat exchangers that serve the purpose of a radiator. On that engine, if you are fresh water cooled, the heat exchanger will be tubular, maybe 4,5,6,7 inches in diameter and 12-18 inches in length, mounted on top of the engine with hoses/pipes attached to it. Sea water runs through it cooling the radiator style pipes inside of it. The closed cooling system is just like a car engine with anti freeze in the system.
 

alldodge

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Mix bad of terms
Someone says fresh or raw I still think raw and or salt.
Fresh is also mixed with antifreeze, and just how is AF and water anywhere near fresh

Either way those are the terms we all deal with, same as elbows and risers which are different items but so many use them interchangeable

ok I'll stop
 

Buster53

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Jun 16, 2022
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34
Mix bad of terms
Someone says fresh or raw I still think raw and or salt.
Fresh is also mixed with antifreeze, and just how is AF and water anywhere near fresh

Either way those are the terms we all deal with, same as elbows and risers which are different items but so many use them interchangeable

ok I'll stop
That’s the way inboard marine engines are referred to…either fresh water cooled (FWC) or raw water cooled (RWC). FWC is a closed cooling system with Fresh water mixed with antifreeze running through the engine block and usually the exhaust manifolds as well.
RWC is the engine block completely cooled by sea water.
RWC is a much cheaper and simpler system compared to FWC, but doesn’t offer the rust and corrosion protection that anti freeze gives the engine.
 

alldodge

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That’s the way inboard marine engines are referred to…either fresh water cooled (FWC) or raw water cooled (RWC). FWC is a closed cooling system with Fresh water mixed with antifreeze running through the engine block and usually the exhaust manifolds as well.
RWC is the engine block completely cooled by sea water.
RWC is a much cheaper and simpler system compared to FWC, but doesn’t offer the rust and corrosion protection that anti freeze gives the engine.

Guess this is you trying to man splain
 

alldodge

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Well, the OP is a newbie to all of this. Just trying to help him learn the differences in marine engine cooling.
OK but you replied to my posting, meaning your replying to me. This is why when I first responded, I did not reply with a previous posted comment.
 

Buster53

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OK but you replied to my posting, meaning your replying to me. This is why when I first responded, I did not reply with a previous posted comment.
Ok, sorry. You are right. I am an idiot and will use this as a teaching or rather, a learning moment. Do my best to not let it happen again
 

DiLevan

Cadet
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May 8, 2022
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11
I appreciate all of the info. The boat came to me with the engine already torn down and I saw a huge weld on the inside of the block. I decided to replace it with a 350 vortec engine I had. I never saw the boat engine intact, which has me at a disadvantage. Is there by chance a video somewhere that might help me understand the conversion from auto to marine? Or a book/manual I can order?
 

Buster53

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Jun 16, 2022
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I appreciate all of the info. The boat came to me with the engine already torn down and I saw a huge weld on the inside of the block. I decided to replace it with a 350 vortec engine I had. I never saw the boat engine intact, which has me at a disadvantage. Is there by chance a video somewhere that might help me understand the conversion from auto to marine? Or a book/manual I can order?
I’m not the person to ask, but I know just enough to say, make sure you do this conversion right. Starter and alternator (as well as anything electrical) must be electrically sealed for marine use, otherwise, the possibility exists for a big boom. Seems I have read that the cam may need to be replaced as well. Cams built for auto use are not really the right fit for marine use. Pretty sure there are other differences as well.
 

alldodge

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No vid or book. Other then items as Buster mentioned, need a marine head gasket, brass or stainless block core plugs, and marine circulating water pump.
 
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