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Full Fresh water plumbing help

K

KMD

Member
I am having issues figuring out the correct plumbing for my 318 log style manifold engine to set them up Full cooling. On Page 11 of the engine manual (I tried to attach but it would not accept PDF images) it has a diagram for LM318, M360 fresh water cooling system (full cool) has the fresh water side:
Leaving Heat exchanger, to bottom of manifolds, out top of manifolds, to water pump inlet through engine out T stat housing and back to heat exchanger.

The thing I don’t like about this set up is the coldest water is the heat exchanger (HX) outlet, this is because you have just transferred all the heat to the raw water in the HX. This diagram then has the water going through the manifolds which heats the water up, then to the motor. I would think you would want the coldest water going into the engine for maximum cooling.

I was surfing the web trying to get some pictures off full fresh water cooling and I found of a guy selling Chrysler marine engines, and he has a ton of pictures to get an idea of cooling hose set up. The website is http://harrysmarinerepair.com/index.php/chrysler-engines.html , . If you look at the first full cooling engine he is selling,He has the fresh water cooling set up like:

Fresh water HX outlet to engine water pump inlet, from water pump to engine, out T stat (T fitting) going to the bottom side of both EXhaust manifolds, out top of exhaust manifolds (connected to a T fitting) going back to heat exchanger to be cooled. The raw water side goes through trans cooler, through impeller pump, through HX, to both risers, out the back of boat. One thing about this configuration is it looks like if the engine T stat is closed no flow is going through the exhaust manifolds.

I was wondering if anybody else has full FWC what their plumbing configuration is, I just want to make sure I do it right. Something else about this set up is I see he has a small hose (3/8” or ½”) bypassing the T stat and sending flow back to HX, what is the purpose of this and I have not seen this on all engines?

Thanks
KMD
 
KMD said:
I am having issues figuring out the correct plumbing for my 318 log style manifold engine to set them up Full cooling. On Page 11 of the engine manual (I tried to attach but it would not accept PDF images) it has a diagram for LM318, M360 fresh water cooling system (full cool) has the fresh water side:
Leaving Heat exchanger, to bottom of manifolds, out top of manifolds, to water pump inlet through engine out T stat housing and back to heat exchanger.

The thing I don’t like about this set up is the coldest water is the heat exchanger (HX) outlet, this is because you have just transferred all the heat to the raw water in the HX. This diagram then has the water going through the manifolds which heats the water up, then to the motor. I would think you would want the coldest water going into the engine for maximum cooling.

I was surfing the web trying to get some pictures off full fresh water cooling and I found of a guy selling Chrysler marine engines, and he has a ton of pictures to get an idea of cooling hose set up. The website is http://harrysmarinerepair.com/index.php/chrysler-engines.html , . If you look at the first full cooling engine he is selling,He has the fresh water cooling set up like:


Fresh water HX outlet to engine water pump inlet, from water pump to engine, out T stat (T fitting) going to the bottom side of both EXhaust manifolds, out top of exhaust manifolds (connected to a T fitting) going back to heat exchanger to be cooled. The raw water side goes through trans cooler, through impeller pump, through HX, to both risers, out the back of boat. One thing about this configuration is it looks like if the engine T stat is closed no flow is going through the exhaust manifolds.

I was wondering if anybody else has full FWC what their plumbing configuration is, I just want to make sure I do it right. Something else about this set up is I see he has a small hose (3/8” or ½”) bypassing the T stat and sending flow back to HX, what is the purpose of this and I have not seen this on all engines?

Thanks
KMD
Click to expand...

KMD,

You're on the right track here, the url provided shows the configuration I currently have on my full FWC log style manifolds on my 72 33 Egg Harbor. If I read your previous posts, same subject correctly, you know the only way to isolate the raw/fresh water is to have the blocking gasket installed between the riser and down angle discharge. I too was unable to locate a stainless gasket, and am currently using the green OCSO provided gasket. Not sure about the longevity of those gaskets, but since I've only had them in for 2 season, it'll be awhile before I pull them again and check their status.

Otherwise the plumbing configuration appears correct, and I also have the Sendure heat exchangers as well, which did require some maintenance.

Mike
 
Mike,
Thanks for the reply. I am going to repost this topic tonight when I get hchrysler 1964-74 thermostat housing.jpgome and add the actual diagrams from the manual. The set ups in thoses photos dont match the drawings. By chance does your T stat housing look like the one I just attached? If so does your bypass (the small line) go to a port just on top of the engine water pump? I will post more info on this in another post later tonight.

Thanks
KMD
 
I'd use some caution if following Harry's information.
He's used galvanized pipe fittings and elbows, and he's using a T-stat housing that is much more complicated than need be... IMO.

Are you able to find a schematic that you can work from?


.
 
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I have the drawings its just the scanner is not working where I am at. I will post them later today. I even drew up a hand drawn schematic I will post.

Whats wrong with using galvanized fittings if they have antifreeze running through them, shouldnt they be ok? I understand on the raw water side but I would think on fresh water it should be fine. My current inlet to my manifolds has hose going up to the manifold with no pipes. I think the pipes sort of dress it up a little.

Thanks agin for the comments.
KMD
 
OK you will have two water pathways; one engine coolant, one raw water from outside. They do not mix. Engine gets a 50/50 mix of Dex cool and water. The engine coolant flows from the top hose of the thermostat housing out to the IN side of the heat exchanger. OUT from heat exchanger to bottom hose of the circulation pump. That's it for the engine side.
Raw water side: From seacock to strainer to raw water pump to heat exchanger to bottom of manifolds and overboard thru the exhaust. This is known as a half system and should be plenty for you. If you want to go all in, then you need a block-off plate between the manifolds and the risers. In this case engine coolant will go from the top of the thermostat housing to a tee fitting where it splits and goes into the lowest point on each manifold. from there it exits the manifold below the riser and goes to the heat exchanger IN. This means more plumbing. The risers get raw water in at their lowest point and then it goes overboard thru the exhaust.
You will use a 160 degree thermostat.
I would only do this conversion if you have a boat that lives in salt or brackish water at a dock. If it is an IO on a trailer it's total overkill.

PS looked at the pic you referred to. The issue with the Chrysler log type manifolds is the air pocket that can form at the high point. Is there a center rise manifold that you can get? If so that would be a better option.
 
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Still having scanner issues will try again in the am. The flow diagrams I am trying to post are from the 318 marine operators manual. it has drawings off full FWC log style (figure 4 page 10), then full FWC on another page center rise manifold (figure 7 page 13). I am doing full FWC log style manifolds with the T stat housing in the above post picture. The log style diagram has it going from top of manifold straight to HX inlet. Then it leaves HX and goes to bottom port of both manifolds, out top of manifolds into suction of engine driven pump. The bypass on the T stat goes from bypass on T stat cover to top of water pump (to stop cavitation).

The pictures on the link to harrys marine has the set up as you stated for the log style engine he has full cooling. it leaves the T stat goes in bottom of manifolds, out top manifolds into HX, out HX into motor. The bypass is fom manifold into top of water pump.

The problem I see with both these set ups is when T stat is closed no flow if going through manifolds.

The center rise drawing in the manifold makes more sense to me it has the main line leaving the T stat going to inlet of HX. the exit of HX goes into engine water pump suction. The bypass on the T stat cover goes into bottom of manifolds out top of manifolds into port on top of water pump. This way when T stat is closed you still have flow going through manifolds.

The raw water side same on both drawings through trans cooler, through pump through riser/elbows out boat.

It will make more sense when I post diagrams. I dont mind hooking it up per manual but eneryone I have seen is not per manual for log style full cooling.

Thanks again for the replys.
KMD







o2batsea said:
OK you will have two water pathways; one engine coolant, one raw water from outside. They do not mix. Engine gets a 50/50 mix of Dex cool and water. The engine coolant flows from the top hose of the thermostat housing out to the IN side of the heat exchanger. OUT from heat exchanger to bottom hose of the circulation pump. That's it for the engine side.
Raw water side: From seacock to strainer to raw water pump to heat exchanger to bottom of manifolds and overboard thru the exhaust. This is known as a half system and should be plenty for you. If you want to go all in, then you need a block-off plate between the manifolds and the risers. In this case engine coolant will go from the top of the thermostat housing to a tee fitting where it splits and goes into the lowest point on each manifold. from there it exits the manifold below the riser and goes to the heat exchanger IN. This means more plumbing. The risers get raw water in at their lowest point and then it goes overboard thru the exhaust.
You will use a 160 degree thermostat.
I would only do this conversion if you have a boat that lives in salt or brackish water at a dock. If it is an IO on a trailer it's total overkill.

PS looked at the pic you referred to. The issue with the Chrysler log type manifolds is the air pocket that can form at the high point. Is there a center rise manifold that you can get? If so that would be a better option.
Click to expand...
 
o2batsea said:
The issue with the Chrysler log type manifolds is
the air pocket that can form at the high point. Is there a center rise
manifold that you can get? If so that would be a better option.
Click to expand...
I agree.
And with a bit better engine performance to boot!


KMD said:
The flow diagrams I am trying to post are from the 318 marine operators manual. it has drawings off full FWC log style (figure 4 page 10), then full FWC on another page center rise manifold (figure 7 page 13). I am doing full FWC log style manifolds with the T stat housing in the above post picture. The log style diagram has it going from top of manifold straight to HX inlet. Then it leaves HX and goes to bottom port of both manifolds, out top of manifolds into suction of engine driven pump. The bypass on the T stat goes from bypass on T stat cover to top of water pump (to stop cavitation).

The pictures on the link to harrys marine has the set up as you stated for the log style engine he has full cooling. it leaves the T stat goes in bottom of manifolds, out top manifolds into HX, out HX into motor. The bypass is fom manifold into top of water pump.

The problem I see with both these set ups is when T stat is closed no flow if going through manifolds.
There should be a by-pass port within the T-Stat housing to allow for coolant flow prior to engine temps causing the "Stat" to open.

The center rise drawing in the manifold makes more sense to me it has the main line leaving the T stat going to inlet of HX. the exit of HX goes into engine water pump suction.
This is true with any H/E system. It's similar to a car/truck radiator system.


The bypass on the T stat cover goes into bottom of manifolds out top of manifolds into port on top of water pump. This way when T stat is closed you still have flow going through manifolds.
That answered your above concern.

The raw water side same on both drawings through trans cooler, through pump through riser/elbows out boat.
Incorrect, unless you're looking at the dual pocket diagram, of which I'm not completely familiar with!

Should be: up through the sea water pick up, through trans cooler, to/through the sea water pump, into the H/E, then out of the H/E onto and through riser/elbows, and then mixes with the exhaust gasses, and then out the exhaust tips.
Click to expand...
 
This may not be an Apples to Apples comparison, and portions of this may not apply to the Chrysler 318/360....... but just run with it for a few minutes, if you will.

This is a SBC Marine engine with a Full Closed Cooling System.
The BBC (demonstrated in the right side schematic) also incorporates the Circ Pump by-pass porting, and apparently this is similar to the Chrysler 318/360.
(the SBC does not incorporate the by-pass)

The engine shown uses a single impeller sea water pump (Alpha drive... pump is in drive).
Your sea water pump is engine mounted.... and I certainly prefer that.

The sea water side of the system is very easy to understand.
The E/G side of the system is almost always a bit more difficult to understand.

Basically, the first in line for E/G coolant (from the H/E), is the engine circulating pump.
Once from the circ pump, the path is through the block and cylinder heads as the Thermostat allows the E/G coolant to escape (so to speak).
From there, you can see the coolant path onto and through the exhaust manifolds, eventually returning to the H/E.
There is enough heat removal capacity remaining in the coolant to take care of the manifolds.

As said, this may not be Apples/Apples, but hopefully it will help explain the E/G path for this one particular system.
It would be interesting to see an actual schematic of your system.

attachment.php
 
Forgot to explain the pdf file. The first 2 diagrams are of a centerrise set up, the 3rd is log style set up, the fourth is a scetch I did on how I would plumb mine using my T stat housing and the log stlye drawing. Again what concerns me is the 3rd drawing which is what I am suppose to follow has cooling leaving HX going through manifolds first then to the engine. All the online pics of diffreent motors I see have cooling leave T stat housing going through manifolds then to HX (which makes sense in my opinion). So why isnt anybody following the factory recomended set up?

Thanks
Kevin
 
KMD said:
So why isnt anybody following the factory recomended set up?
Click to expand...
Kevin, I believe it's because it's rather "old school" and somewhat outdated.

Side note..... and my pet peeve...... why these people call this FWC is beyond me. :confused:
There is nothing fresh about Ethylene Glycol and distilled H2O. :mad:
In my little world, these are Closed Cooling Systems!
Anyway....... got that off my chest now. :p

********************************************************************

I was able to view the PDF file.
I must say.... what a strange way to layout a schematic.... but I can understand it.

BTW.... I'm using: H/E = Heat Exchanger...... E/G = Ethylene Glycol coolant.

Looks like they're taking a portion of the by-passed coolant (pre-thermostat) shown in red, and running this to the exhaust manifolds, and then back to a suction port in the circ pump.
(any port in the circ pump will be suction)
This is good!

The thermostat eventually has last word regarding coolant temperature.
If the system needs more cooling, the stat opens, allowing the circ pump to pull in more E/G from the H/E.

None of my business, but I'd sure loose that dual or single pocket belt driven sea water pump, and see if you can go with a crankshaft pump.
 

Attachments

  • Chrysler 318 360 full system .jpg
    Chrysler 318 360 full system .jpg
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Here's a better image showing the coolant path around the cylinders and inside of the block.
I realize that this is a SBC, not a Chrysler...., but the paths are very similar.


attachment.php
 
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Ricardo,
I agree about crankshaft pumps I am a huge fan of them. The problem is (I stated in an earlier post) I have a marinette and the front of the motors about 3" from the bulkhead, I have no room for crank pumps. Plus I have the single sherwoods and they are in good shape and money is tight right now.

Thanks
KMD
 
Ricardo,
Thanks for the reply. When you say "Kevin, I believe it's because it's rather "old school" and somewhat outdated." I would think if this is outdated wouldnt chrysler of put out a service bulliten saying hey dont follow manufactures recomendation for cooling, and put out a new drawing showing the new recomendad plumbing? I wonder if the thousands of full closed cooling systems set up per manufacture recomdations had any cooling issues? Has anybody set it up both ways and measured temps to see which set up is better?

I personally like the method set for for the center rise manifolds. My issue is I would have to get a new thermostat housing if I did this. My current T stat housing (in a picture above) has the 1" I.D line going to the HX when T stat is open. My bypass is only 3/4" in diameter. I would have to T off the byppass to run through both manidolds. I dont believe this would give enough flow to each manifold. I could always put a small rubber hose on the bypass on the T stat housing and plug it, then pull the plug out of my intake (right below the T stat housing) and use that to feed both manifolds. i think thats a 1" hole but not sure.


Thanks
KMD
 
KMD said:
Ricardo,
1... When you say "Kevin, I believe it's because it's rather "old school" and somewhat outdated." I would think if this is outdated wouldnt chrysler of put out a service bulliten saying hey dont follow manufactures recomendation for cooling, and put out a new drawing showing the new recomendad plumbing? I wonder if the thousands of full closed cooling systems set up per manufacture recomdations had any cooling issues?

2... Has anybody set it up both ways and measured temps to see which set up is better?

3... I personally like the method set for for the center rise manifolds. My issue is I would have to get a new thermostat housing if I did this. My current T stat housing (in a picture above) has the 1" I.D line going to the HX when T stat is open. My bypass is only 3/4" in diameter. I would have to T off the byppass to run through both manidolds. I dont believe this would give enough flow to each manifold. I could always put a small rubber hose on the bypass on the T stat housing and plug it, then pull the plug out of my intake (right below the T stat housing) and use that to feed both manifolds. i think thats a 1" hole but not sure.
Click to expand...


1... I don't know enough about the Chrysler Marine to say one way or another. I would suspect that these are proprietary parts, and the OEM most likely enjoys proprietary parts sales.
Keep in mind that this system was designed quite a few years ago.

Since we don't see any "new school" Chrysler Marine engines, it's tuff to say what Chrysler Marine would be installing today.


2.... That would be interesting to see.


3... I too would prefer the center-rise setup.
But agian, I don't know enough about the Chrysler Marine to actually say one way or another.

If this was a GM or Ford, I probably could.


.
 
Call it Closed cooled if theres Antifreeze/coolant (what everybody calls it) cooling the engine

Jeez Rick!!

I seems like it takes my engines about 10 mins to get warmed up to 160,and thats with a 1/2 pipe from the street barely keeping up,Im wondering if my 2 pass Heat exchangers can handle atleast cooling the 826 logs and just plumbing the elbows to Salt/Raw

not highjacking just throwing in some food for thought
 
greasemonkey said:
Call it Closed cooled if theres Antifreeze/coolant (what everybody calls it) cooling the engine
Jeez Rick!!

not highjacking ....... just throwing in some food for thought
Click to expand...
And I'll do the same!

Here's my reasoning for referring to these systems as "closed cooling" -vs- "FWC"........ and I'm basing this on what I've seen and read in on-line forums over the years, and while talking to customers.

We all know what RWC means, so there's little chance of misinterpretation here.
We'll also hear the term "Open" system to describe the same RWC system.

FWC (aka "fresh water cooling") has become synonymous with an engine closed cooling system (i.e., heat exchanger and ethylene glycol coolant).

FWC or FW (minus the "C") in a misnomer fashion, has also become synonymous with running exclusively in river or lake water (apposed to ocean salt water)

FW has also become synonymous with our potable water systems.

So you can see that the FW part of FWC can/may take on several meanings.

All, with exception to Ethylene Glycol, could be considered "fresh".

A cooling system that incorporates a Heat Exchanger and Ethylene Glycol coolant, is a "closed loop"... would you agree?
If you do agree..... when we refer to these systems as "Closed Cooling", there's less chance of misinterpretation..... yes/no?
Less chance of misinterpretation = better communication.... yes/no?

BTW, this FWC -vs- Closed Cooling is my Pet Peeve.
I'm not trying to push this off as being anyone else's Pet Peeve........ and I don't expect it to be.

Call these what you wish....... and we'll some how figure out what's being discussed.

Fair nuff? :D



.
 
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KMD,

Instead of wasting time and debating semantics, I'll add some valuable information to your thread. After all, isn't that why you're here?

Keep in mind that the t-stat style you're showing doesn't completely stop coolant flow even when the t-stat is closed. Coolant will still exit through the inside of the t-stat body and out the "top hat" even when the t-stat is closed. This style t-stat just stops coolant from entering the motor when closed, but coolant will still exit.

I think this addresses your concern about the logs getting coolant when the t-stat is closed.

-JJ
 
JJDebeers,

After all this going back and forth I have decided to hook up my FULL CLOSED cooling per manufacture recomendatiuons which is the first diagram of 3 that I attached earlier in this thread. I have not seen a motor plumbed this way everybody seems to plumb it how they please but to be safe I will follow manufacture drawing. I agree with you, I have spent a good amount of time looking at this T stat and figuring out how it operates. When the T stat is closed antifreeze will still exit the motor (through the Top hat) go into suction (top side of engine driven water pump) and keep recirculating through the engine. The whole purpose of the Top hat style is to just block antifreeze from going to heat exchanger when T stat is closed. I still dont like that no antifreeze is flowing through manifolds when T stat is closed but thats how they say to do it for this style manifold so that is what I am going to do.

Thanks again for your reply its greatly appreciated.
KMD
 
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