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Generator cooling from garden hose.

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captcwc

New member
I am curious why you cant' bypass the raw water pump and feed water from a garden hose directly into a generator's water cooling system. I always hear everyone say let the inboard engine raw water pump draw the water in, never force it. I am wondering why? The westerbeke generator's raw water pump failed and at the same time I have having carburetor issues. It's going to take a while to get the pump fixed so I wanted to hook up the garden hose and run it that way. Does anyone see a problem?
 
The cooling water, via the seawater pump, is RPM controlled, allowing the engine and exhaust system to receive the correct amount of water for a particular RPM.
This also controls the amount of water that enters the exhaust manifold’s “mixing chamber“.

If you were to bypass the seawater pump and were to force garden hose water in, you will risk sending too much water into the system.

If you simply need to hear it run, do a quick 5 to 10 second dry start.
If you need to run the engine and fiddle with the carburetor, you'd better wait for your seawater pump parts.





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Sounds responsible to me, but two questions, what does RPM stand for (I think I know but want to make sure), and what happens if one overcomes the RPM regulation, does water end up in the oil?

I took the exhaust manifold chamber off and it appeared that the water exits the chamber at the same time the exhaust exits and I didn't see how the water could overcome the system, accept in the exhaust muffler/silence, which I would not use because I have taken the generator out of the boat.
 
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captcwc said:
Sounds responsible to me, but two questions, what does RPM stand for (I think I know but want to make sure),
RPM = revolutions per minute... i.e., engine speed in revolutions per minute.

Gasoline Marine generators are governor controlled to operate at between 1500 / 3000 rpm 50 Hz or 1800 / 3600 rpm 60Hz.
(this may vary depending on the manufacture)

This means (unless it has a "warm up" cycle) that when you fire it up, the governor is going take over and increase RPM to their specification.
So don't be surprised if it revs up when you start it.
However, you should be able to reach around and hold the governor linkage and operate it near idle speed..... although these carburetors typically do not have a low speed circuit.

and what happens if one overcomes the RPM regulation,
As said, the seawater pump's volume is RPM controlled. In other words, at the operating engine speed, the pump's volume has been pre-determined.
If you were to force garden hose water into the cooling system, you will risk forcing more water in than what the system is designed for (as per RPM).

does water end up in the oil?
Not necessarily. That would get us into another topic.

I took the exhaust manifold chamber off and it appeared that the water exits the chamber at the same time the exhaust exits
Well, as the seawater cools the engine (via the Heat Exchanger) the remaining and exiting seawater cools the exhaust manifold.
As the seawater leaves the exhaust manifold, it enters what we refer to as a "mixing chamber", where it then enters the exhaust gas flow and out to the muffler.

and I didn't see how the water could overcome the system, except in the exhaust muffler/silence, which I would not use because I have taken the generator out of the boat.
If the generator is removed from the boat, and if the exhaust manifold has also been removed from the generator engine, I would NOT run it.

I would suggest that you wait until the manifold is re-installed, and only after the seawater pump parts arrive and are installed.
Then you will be able to supply Non-Forced garden hose water to the seawater pump's inlet.


Also, since this is a gasoline engine generator, you will want to make sure that the wire harness and controls are able to activate the solenoid shut-down valve.
(this is a needle type valve that closed off the carburetor's main jet upon engine shut-down)

If you are unfamiliar with this and/or are not comfortable doing all of this, I would suggest taking it to an authorized dealer.
The fuel/air mixture must be correct, the governor controlled engine RPM must be correct, and so on.
Click to expand...



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You can run your genset off the garden hose with out the raw water pump... Start the genset, turn on the hose and regulated the water with the hose bib, it does not take much to cool it. Most WB gensets run around 1800 rpm.
 
I don't see any issue using a hose, assuming it has adequate product....

If the set is out of the boat, you'll need some thing to ensure the wet exhaust product doesn't soak the equipment...
 
If you do this, you will want to re-install the exhaust manifold and direct the wet exhaust away from the area, as Mark suggests.

I would regulate the water supply, as Chris suggests, and would also turn the water supply off just prior to shutting down the engine.


Keep in mind that with the generator out of the boat, you will not have an active remote instrument panel.
In other words, you will not have an operational temperature gauge to monitor the engine temp.


I believe that all else will work, including the main jet shut-down solenoid.

Westerbeke gas engine shut down solenoid.jpg
 
My comments are a little vague and I appreciate the concerns. I only removed the exhaust manifold to see what would happen when I ran water through it. I intend to install it before running.

Also, I am pretty knowledgeable about boats/mechanics but I just recently purchased a boat that has 2 454 crusaders and a generator, the one not working. And all three have hose fittings on the raw water strainers so, apparently they are used to flush each engine with fresh water. I have always heard to not hook up a garden hose to a generator and that is where my questions come from. But, in the the same line, I am wondering what damage would happen if I hooked up a hose to the main engines as well. (maybe the strainer inlets are for drawing in antifreeze for winterization since the boat came from the north). Granted, the engines are fresh water cooled and so, I think, hooking a hose to the engine raw water strainers would only run through the heat exchanges. The generator is different, it is raw water cooled. I am a bit confused here. Is the set up on my boat for drawing in antifreeze for winter or is it a flush system to remove saltwater on a routine bases?
 
the major issue with raw water pumps and garden hoses is inadequate flow from the hose....many impeller based pumps can provide much more output than the hose can deliver....run the pump starved and it may be damaged in short order...

Regular hose fittings on the strainer are potential red flags....many 'home made flushing attachments' have been shown to leak air which impacts the cooling capacity of the water flow.....they could be for routine flushing or annual winterization....
 
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captcwc said:
My comments are a little vague and I appreciate the concerns. I only removed the exhaust manifold to see what would happen when I ran water through it. I intend to install it before running.
That would be good!

Also, I am pretty knowledgeable about boats/mechanics but I just recently purchased a boat that has 2 454 crusaders and a generator, the one not working. And all three have hose fittings on the raw water strainers so, apparently they are used to flush each engine with fresh water.
Yes, that is most likely why that has been done.
It's typical to see a back-flow prevention valve on a system like that.
Pictures would be helpful.

I have always heard to not hook up a garden hose to a generator and that is where my questions come from. But, in the the same line, I am wondering what damage would happen if I hooked up a hose to the main engines as well.
***(maybe the strainer inlets are for drawing in antifreeze for winterization since the boat came from the north).
Possibly.

Granted, the engines are fresh water cooled
By "fresh water cooled" are you saying that they are fitted with Closed Cooling Systems?
If so, the above *** would be safe to do.


and so, I think, hooking a hose to the engine raw water strainers would only run through the heat exchanges.
That system would push AF through the seawater side of the heat exchanger and through the seawater side of the exhaust system.

The generator is different, it is raw water cooled.
Are you certain that your Westerbeke generator is not fitted with a Closed Cooling System?

I am a bit confused here. Is the set up on my boat for drawing in antifreeze for winter or is it a flush system to remove saltwater on a routine bases?
It could be for either/both.
Again, pictures would be very helpful.
Click to expand...
 
captcwc said:
My comments are a little vague and I appreciate the concerns. I only removed the exhaust manifold to see what would happen when I ran water through it. I intend to install it before running.

Also, I am pretty knowledgeable about boats/mechanics but I just recently purchased a boat that has 2 454 crusaders and a generator, the one not working. And all three have hose fittings on the raw water strainers so, apparently they are used to flush each engine with fresh water. I have always heard to not hook up a garden hose to a generator and that is where my questions come from. But, in the the same line, I am wondering what damage would happen if I hooked up a hose to the main engines as well. (maybe the strainer inlets are for drawing in antifreeze for winterization since the boat came from the north). Granted, the engines are fresh water cooled and so, I think, hooking a hose to the engine raw water strainers would only run through the heat exchanges. The generator is different, it is raw water cooled. I am a bit confused here. Is the set up on my boat for drawing in antifreeze for winter or is it a flush system to remove saltwater on a routine bases?
Click to expand...

They are there for flushing and for antifreeze. I would remove them, As Makomark Suggested. As for your 454's I would also remove the sea strainers and install eel grass strainers on the bottom of the hull....The heat exchanger on a Crusader 454 is inadequate and any restriction IE..(sea strainer) will have the exhaust steaming. There is a large size Heat exchanger for the Crusader 454, if you can find them, that will allow your engines to run at actual thermostat spec.
 
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