Engine fresh water flush

[Contento]

On my prior boat, a Valiant 42 sailboat, I would flush the main engine and genset in prep for summer, inwater, layover by closing the raw water thru hull, then inserting a fresh water garden hose into the raw water inlet strainer, turn on the fresh water, start the engine and let it run until it warmed to the point the thermostat opened and then continue to run it for 15 to 20 minutes to thoroughly flush the engine. Once the engine was running, I'd adjust the garden hose so that the flow would keep up with the engine water pump and overflow into the bilge slightly. The thru hull would be kept closed during the layover. Does anyone see a problem with doing likewise with my D3 and Maze genset? Of course careful observance of the water flow is paramount.

 

[Shano]

Shouldn't be any issue at all - we do the same with our D6 for winterizing, first a flush and then we use the potable antifreeze.

 

[knotflying]

You mentioned running the engine until warmed and the thermostat opened. These systems are closed systems. The raw water is used for cooling the closed system. Hence, there is no thermostat in the system used for the raw water and no need to let the engine warm up. Also, I would assume one was doing the flush when they returned from a trip and the engine would already be warmed up.

Just some thoughts.

 

[Contento]

Knotflying, you are absolutely correct, a lapse in my foggy brain. It is the raw water segment of the system that needs flushed and there is no thermostat therein. Right or wrong, I usually do NOT flush either the main engine or genset at the end of each use. Normally I do a periodic flush. Am rethinking this and think I'll try and be a bit more diligent about more frequent flushing. Side note, taking the covers off the Maze genset the other day I noted salt water encrustations around the raw water pump, in fact it appeared salt water had actually been slung around in the close vicinity of the pump. I am thinking a seal has failed. Anyone had a similar problem and diagnosis?

 

[Capt’nKarl]

My two cents on raw water flushing. I use a 5 gallon bucket drilled at the bottom and fitted with a garden hose connection and a short hose segment to connect to the raw water system. I fill the bucket with water from the garden hose and then use a short hose segment connected from the bucket to the raw water intake. This eliminates the worry of over pressurizing the raw water intake. I control the volume of water going into and out of the bucket according to the engine RPMs to keep enough water flowing into the raw water system. Works great! Cheers!
Karl

 

[NorthernFocus]

My two cents on raw water flushing. I use a 5 gallon bucket drilled at the bottom and fitted with a garden hose connection and a short hose segment to connect to the raw water system. I fill the bucket with water from the garden hose and then use a short hose segment connected from the bucket to the raw water intake. This eliminates the worry of over pressurizing the raw water intake. I control the volume of water going into and out of the bucket according to the engine RPMs to keep enough water flowing into the raw water system. Works great! Cheers!
Karl

Same net effect as closing the sea cock, taking the top off the strainer and sticking a hose in it.

 

[knotflying]

Running a mixture of some salt away through the system does not hurt either.

 

[YukonRon]

My two cents on raw water flushing. I use a 5 gallon bucket drilled at the bottom and fitted with a garden hose connection and a short hose segment to connect to the raw water system. I fill the bucket with water from the garden hose and then use a short hose segment connected from the bucket to the raw water intake. This eliminates the worry of over pressurizing the raw water intake. I control the volume of water going into and out of the bucket according to the engine RPMs to keep enough water flowing into the raw water system. Works great! Cheers!
Karl

Same net effect as closing the sea cock, taking the top off the strainer and sticking a hose in it.

True, but my strainer never stays full with the hose in it.
I'm not sure if I'm keeping up with the demand, or sucking air. The bucket adds a reservoir to give a visual clue. I like it.

 

[Capt’nKarl]

I don’t stick a hose in the strainer. I modified the hose leading to the raw water pump with a tee adapter that has a male garden hose fitting. The hose from the bucket has the female fitting that screws on to the male tee. The water flow from the bucket, which is set up on the swim platform, is totally regulated by the engine RPMs. All I have to do is keep water in the bucket. This method is simple,safe and doesn’t get water everywhere which allows me to do a good engine flush.
Karl