Fresh Water Flush set up for engines, genset, AC

[drapem1]

Anyone with experience and/or opinions on installing T type valves with hose connectors so able to flush raw water systems on engine, genset, and AC units that use salt water cooling?
It would make sense (from my experience fresh water flushing outboards and other inboard engines) to put a connector just above the thru hull sea cock valve on raw water intakes (specifically talking about a 50 ft monohull with 110 yanmar and 12kw genset). Then when leaving boat for more than a couple weeks, hook up fresh water hose to intakes and run engines for a few mins to clear out the salt water. Also through the AC intake to clear salt water in AC pump and small tube lines.
Has anyone made this installation and operation work?

[ranger58sb]

We have Groco flush valves attached to main engine and AC intake thru-hulls... with hose from there to strainer and then to engine or AC raw water pumps. In our case, mostly used for winterizing (mains) and periodic system clean-out (ACs).

Haven't added one to the genset line yet, though that's for this year. Can't reach the thru hull easily, so I'll likely add the flush valve after the strainer...

-Chris

[drapem1]

Is there a issue (or potential issue) with using a fresh water faucet source to flush as the water pressure may cause a problem with too much water entering the exhaust mixing elbow and possibly allowing water entry into cylinders?

Other idea would be to attach hose to flush fitting and then use a 5-10 gallon water jug as fresh water source and let the engine, pump, etc pull water from jug as it normally would through the seacock.

Thoughts?

[laika]

The mr. bucket solution is elegant and simple. Feed hose and raw water intake into bucket with whatever solution you want. Could be pure fresh water, a mix of polypropylene glycol, etc. No reason to pressurize the system with a direct hose hookup, or introduce more rarely-used valves when a bucket can easily accomplish the task at hand.

My two cents at least.

[flyingfin]

Did it for years on a twin engine sportfish with no problems. Install the tee fitting with a hose bibb between your thru hull, or strainer, and raw water pump. Use an old washing machine hose to make the final connection.

Do not close the thru hull when first starting the engine, and measure garden hose delivery (gallons per minute) so you have an idea of how much flow to allow thru the hose into your raw water supply so it matches your normal exhaust water flow. Be CAREFUL to not over-pressure your raw water system. I always left the garden hose connection loose so some fresh water flowed into the bilge, wrap a rag around it so it doesnt spray over the engine but still lets you know you have flow.

Run for several minutes to ensure your engine thermostats open. Shut down engine, let fresh water run another 30 seconds then 1. shut off fresh water garden hose 2. Close hose bibb and finally 3. close the thru hull.
You will trap enough fresh water in your thru hull valve and raw water strainer. Leave the ignition key hanging on the thru hull so you dont start without opening.

[ranger58sb]

Originally Posted by drapem1

Other idea would be to attach hose to flush fitting and then use a 5-10 gallon water jug as fresh water source and let the engine, pump, etc pull water from jug as it normally would through the seacock.

We do a version of that. I'm hesitant to use dock water pressure on engines...

And we use the clean-out idea several times throughout the year (AC, winterization, etc.)... so I made up a faucet on a clear storage box... so I can monitor flow and then afterwards the box becomes the storage container for a transfer pump and several different hose/fitting (water and compressed air) combinations...

-Chris