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Pinging Chrysler Marine experts and owners re; raw water cooling system options!

RicardoMarine

RicardoMarine

Gold Medal Contributor
Rather than further Hi-Jack Jfreeman's thread, I thought that I'd begin a new thread.

First... I'm not a Chrysler Marine expert in any stretch of the imagination.
Secondly..... I'm not posting this to degrade or bash the Chrysler systems.
Thirdly...... this is a proposal and question thread only, simply based on some of my observations of the Chrysler raw water cooling systems whereby the dual pocket belt driven pump is used.


Questions first:
  • Are you guys OK with the belt driven dual pocket pumps, and do these systems seem to be trouble-free?
  • Do these seem to be overly complex?
  • Do these pose any issues routinely?
  • Do these systems appear to defer routine maintenance related to impeller and/or pump inspection?
  • Would a single crankshaft pump, and a more simple exhaust cooling water system, benefit you?
  • Do you think that the crankshaft style pump system could be incorporated?
  • Or would it be best to leave things alone?

The Dual Pocket sea water pumps and engine and exhaust plumbing systems appear to be overly complex to me, and would appear to offer issues that other systems do not routinely offer.
Again, I'm not an expert on these systems, but have recently been looking at them on the forum here.

This image below may be similar to the typical dual pocket pump sea water cooling system layout.
(this is not my image... I found it while doing a search)

To me, this system appears to be more complicated than need be.
My experience is that the belt driven sea water pumps intrinsically delay or defer maintenance due to the pump requiring removal in order to change an impeller. Not just Chrysler's belt driven pumps.... most all belt driven pumps... Merc, Volvo Penta and others included!

Most any of us who work in this field routinely address over-heating issues simply because an owner does not perform pump/impeller maintenance frequently enough.
I find that those owners with crankshaft style pumps, tend to stay more on top of it... IMO.

(again.... not my image)
23716.jpg



Many raw water cooled Marine engines are fitted with the crankshaft style pump.
Take a look at how simple the plumbing is.

The T-stat housing allows for the By-Pass to occur within the body of the housing.
As with any engine, the engine circulating pump "charges" the engine block with a supply of cool sea water.
T-stat opens, allows cooling water to escape as needed, and this "spent" sea water is then directed back into the exhaust system supply.
Meanwhile, the balance of the pump's sea water is continuously flowing onto and out the exhaust system.



attachment.php



Granted, this change may be quite involved, but it would be a one-time deal ONLY.
It may also require a different style exhaust manifold/riser configuration.... you guys would know more about that!
It would require some adaptation to the crankshaft pump base plate as to fit the Chrysler front engine pulley/balancer.
It would also require enough space in front of the engine for the pump location.
But again..... it would be a one-time deal ONLY.

What are your thoughts?


.
 

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My experience is big block only. All three of the dual pocket pump Chrysler engines I work on are just fine and I have zero issues with cooling. The problems I have seen in the past are owner caused by being clueless or being cheap.

Problems seem to happen when somebody tries to save a buck and cobble on Chebby parts. One of the most common is the use of a cheap T-stat. The right one is $70.00. A top hat T-stat is a quality piece and will last over 500-600hrs. A $8.00 chebby T-stat may last 100 hrs.


Chrysler loved to use formed hoses and when they ware out, kinked heater hose seem to be a common replacement. For some reason people seem to remove the return water spliter. Use of non wire reinforced hose on the suction side of the pump is something I have seem as well.
 

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Is this the way the thermostat is suppose to look like? I thought mine was shot because it looks like it couldn't stop water because you can see right through it. Is that the way it is suppose to be? Thanks
 
Jfreeman1412 said:
View attachment 4996
Is this the way the thermostat is suppose to look like? I thought mine was shot because it looks like it couldn't stop water because you can see right through it. Is that the way it is suppose to be? Thanks
Click to expand...
When it is cool and closed the water exits out the top port of the housing and returns to the suction side on the pump. When it's warm and up to temp the hat moves up and closes off the top port and the water exits the bottom port and then goes to the risers.
 
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So...Sorry you are running the raw water to both ports on the bottom of the pump? If so how hot do your exhaust manifolds get?

closed the water exits out the top port of the housing and returns to the suction side on the pump
Click to expand...

Or are you running raw water to only one side of the pump? And if so do you know which side? Front or rear pocket?
 
Jfreeman1412 said:
So...Sorry you are running the raw water to both ports on the bottom of the pump? If so how hot do your exhaust manifolds get?



Or are you running raw water to only one side of the pump? And if so do you know which side? Front or rear pocket?
Click to expand...
I use the stock splitter and from the looks it would send most of the by-pass water to the bigger engine pocket.
 

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Tahoerover, when I hear the term "splitter", I don't think of a stanard bronze pipe T fitting.
As with electrical current, liquids will typically take multiple paths of least resistance, so the splitter or diverter will often incorporate a web at the interior to ensure that it offers proportunate flow regardless of resistance.
Does this splitter incorporate a web of some sort?

OH... I found that I had an old schematic that I had added color to as to show cold, warm and hot sea water flow.
Blue being cold sea water.
Yellow being sea water charged into the engine block via the Circ Pump.
Red/blue being a blend of by-pass sea water and engine tempered sea water.

I don't know if this helps with the schematic or not.
 

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RicardoMarine said:
Tahoerover, when I hear the term "splitter", I don't think of a stanard bronze pipe T fitting.
As with electrical current, liquids will typically take multiple paths of least resistance, so the splitter or diverter will often incorporate a web at the interior to ensure that it offers proportunate flow regardless of resistance.
Does this splitter incorporate a web of some sort?

OH... I found that I had an old schematic that I had added color to as to show cold, warm and hot sea water flow.
Blue being cold sea water.
Yellow being sea water charged into the engine block via the Circ Pump.
Red/blue being a blend of by-pass sea water and engine tempered sea water.

I don't know if this helps with the schematic or not.
Click to expand...

No web, so you want to add a crankshaft pump and a circulatory pump to a standard dual pocket set up. Seems like a lot of fab work with little to no pay off.

So you would need:
New crank shaft pump with mounts for a chrysler dampner
new timing cover
new circulatory pump
new t-stat housing
a bunch of new nose

It would be easily a $1000 before you were done. My Arabian stays nice and cool while spinning 5800 rpms and has over 500hp.

Were is the benefit?
 
Tahoerover said:
  1. No web, so you want to add a crankshaft pump and a circulatory pump to a standard dual pocket set up. Seems like a lot of fab work with little to no pay off.
  2. So you would need:
  3. New crank shaft pump with mounts for a chrysler dampner
  4. new timing cover
  5. new circulatory pump
  6. new t-stat housing
  7. a bunch of new nose
  8. It would be easily a $1000 before you were done. My Arabian stays nice and cool while spinning 5800 rpms and has over 500hp.
  9. Were is the benefit?
Click to expand...
Again, let me explain that this is just being thrown into the mix here for discussion as to see what you guys think of the idea.... not to upset anyone!
I have no ill attitude towards the OEM Chrysler systems. If it works, and works well witout any complications, then great!
Not being a Chrysler guy, I'm at somewhat of a disadvantage that perhaps you guys can help me with.

I'm just sharing an idea! :D




  1. Not "to" a standard dual pocket set up.... this would be in lieu of a standard dual pocket set up.
  2. So you would need:
  3. Correct. It would require a one-time modification.
  4. Well, again and as said, I'm not a Chrysler Marine expert..... you guys would know whether or not this is required.
  5. See above.
  6. Yes.... I believe that the T-Stat housing would need to provide the by-pass differently than how the Chrysler T-stat housing does it. But again, you guys would know more so than I.
  7. Yes, and again..... a one-time ordeal.
  8. The Johnson F6B-9 is approximately $150- 180.
  9. Ease of a single impeller pump that lends itself easily to impeller changes, and a much simplified system.




For my own personal tastes, I've exclusively owned marine engines that are equipped with the closed cooling system. I'm in the PNW, and we have winter freezing temperatures, and we occasionally run in ocean water.
This same crankshaft pump arrangement can just as easily be used for a CCS.
I see so many set ups like this, and that work well to boot.


.
 
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An oil cooler would install upstream of the sea water pump, and will be first in line for cold sea water.

As for the exhaust manifolds, we'd need to understand the T-Stat housing porting, and how it provides the "by-pass".
What the engine requires for heat removal, is charged into the block via the engine circulating pump.
The T-stat releases this water as required by engine temp.

this schematic supplys hot water to the manifolds it looks to me.
Click to expand...
That is an easy one to explain.
Any and all sea water that is not being charged into the engine block, is being continuously provided to the exhaust manifolds and out the exhaust.
This occurs within the T-Stat housing.
These sea water pumps are designed for enough volume to handle both engine cooling demands and exhaust demands..... baring no restrictions.


Here's a cut view of a Non-Chrysler style.

Blue = incoming cold sea water.
Yellow = sea water to Circ Pump.
**Red = cooling water leaving engine.
Blue at Twin outlets = to exhaust manifolds/risers.
**Where the lines all converge, would be a mixing chamber (so to speak) and where the By-Pass occurs.



With most any Raw Water Cooled Marine Engine, the majority of the sea water is by-passing actual engine demands.
This is just plain physics.


Not fully understanding the engine bay temperature thing.
BTU's are BTU's, and must be removed, yet no system removes all heat.
If they were able to, we'd have engines operating at close to sea water temperatures against all manufacturer's recommendations.

The F6B-9 is commonly used on big block engines..... the F5B-9 is seen used on the small block engines.
Sherwood and Jabsco also offer a large volume crankshaft pump.



And yes..... it would certainly require some work and re-work of the existing system.
Like said, it's a one-time deal, from that point on, you're done.


Again, this is for discussion only, not arguements.

.
 

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Well, first of all, we have to think outside of the box, and be capable of fabrication! If you are not an outside of the box thinker, then this certainly isn't for you!
You have made your points, and I appreciate them.
So what say we just simply let the others chime in and leave their comments?
Fair nuff?

.
 
This actually has zero to do with the Chrysler scenario.

Some of the Mercruiser guys run into difficultly with Merc's belt driven sea water pump on the later MPI engines.
This person needed to replace the entire pump.
The pump is apparently difficult to access and remove.
The new pump was six weeks out.
He'd had it with the belt driven pump location and with the difficulty with impeller replacement.
Upon my suggestion, he went from the OEM low mounted Starboard side belt driven pump location:

(pump had been removed prior to this photo, and would have been just Stbd of the crankshaft)

attachment.php


To this Johnson crankshaft pump:

attachment.php



He suffered no loss in total sea water volume.
This style pump has no side load from a drive belt.
Bearings virtually last for years and years.
No pump removal for impeller access.
Four screws and he can remove the impeller.

Again, I'm just tossing this out there.


.
 
RicardoMarine said:
Jfreeman, they show up on my end. I'll see if I can post them in a different format.

Here's a happy SBC owner who did the crankshaft pumps back in March.
These were not Chrysler engines, but he is happy with the pumps.


Greasemonkey, perhaps you need a reminder of your level of expertise! Do you recall the "Number one on Chrysler Marine 318" thread?
With 6,132 views.... I would be terribly embarrassed.



.
Click to expand...
So if the chebby boys are happy ,it's a universal mod and us Chrysler boys should follow suit?
LOL!!!
 
Now Rick,heres a real duo-prop boat that acctually runs...not just one we talk about like it isnt in the weeds behind the house all butchered up with a butter knife
 

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