automatic raw water drain

[bostonhatteras]

Here's an idea for those times when you just don't have enough to keep yourself busy. An automatic drain for the raw water side of the heat exchangers and, if the particular set up requires , the exhaust risers. the two main components are a fuel pressure switch and a normally open electrovalve. The set up is straightforward. plumb in the fuel pressure switch and supply 12 v or whatever low voltage you use. plumb the electrovalve to the heat exchangers existing drain and to the bilge. wire the electrovalve to the fuel pressure switch. when the engine starts the fuel pressure will close the fuel pressure switch sending 12v to the electrovalve. when the electrovalve is energized it will close and hold the raw water in. as soon as you shut down, the electrovalve reverts to its normally open position and drains the raw water. Just a thought.

[GJH]

Why would you want to do that? Did you think of the implications of failure due to bad connections, lose of 12v power etc? Far outweigh any benefit I can think of, what exactly are you trying to accomplish?

[bostonhatteras]

I have drains in there now. they are manual ball valves with 1/4'' thread do you really think one or even three 1/4'' holes would cause a catastrophic failure? the raw water pump flows so much water the system wouldn't even notice the difference and the bilge pump could easily keep up with it. Why would someone want to drain the raw water side of the heat exchanger? To prolong the intervals between cleaning the heat exchanger element. you don't need zincs to protect metal that isn't immersed in salt water. there are two very good reasons to drain the heat exchangers and why I have manual valves and do it every time I return to the dock.

[Boatsb]

Salt water leaves a residue. Unless you rinse it your not gaining much. The best way to keep them clean is to run them. Spend time using the boat and you get more enjoyment out of it.

[jim rosenthal]

I agree. Why introduce more complexity if it isn't absolutely necessary? I also wonder if anything that makes maintenance less frequent is a good idea. It seems to me that recreational boats need more attention generally, not less.

[bostonhatteras]

[ I also wonder if anything that makes maintenance less frequent is a good idea. It seems to me that recreational boats need more attention generally, not less.

I definitely think this depends on your perspective. I know you say generally, but where is that line drawn? I would say dripless shaft seals eliminate a fair amount of maintenance. as needed coolant filters (sca's leaching filters) do also. hydrocaps on batteries or even gel batteries. Getting to total basics, float switches and antifouling paint. there are things we just don't have to deal with and we take it for granted. the trip into the engine room to drain the heat exchanger does give me a look around for things amiss, however so does going in to check the oil. as mentioned previously salt leaves a residue but for the most part it is water soluble and doesn't build up the way shell creatures will. the little shell stuff that eventually clogs up the heat exchanger cant grow out of water and that is what is eliminated by draining the heat exchanger. albeit, the kiss principle does carry some weight here but dealing with caustic acids or total disassembly isn't a picnic either. I bet no one here misses the regular 25,000 mile or less tune ups on the old cars where you had to change and set the points and condenser rotor and cap, change the spark plugs, set the idle speed and adjust a finicky bimetal choke! yeah everybody forgot about that because it was so easy to forget! No one is looking back either!

[Boatnut]

You truly must be kidding here. Boats are work, no way around it, if you want a hobby with no work, you might consider tidly winks, or a game of Old Maid. Boating is not for you unless you can afford to pay someone to do the routine stuff needed..

[Boatsb]

Maintenance is always necessary. Using a vessel keeps things lubed and dry. If the engine runs at temp for an hour there's less chance of corrosion on points. You will get more hours of use between maintenance and corrective repairs if they run weekly .

[bostonhatteras]

You truly must be kidding here. Boats are work, no way around it, if you want a hobby with no work, you might consider tidly winks, or a game of Old Maid. Boating is not for you unless you can afford to pay someone to do the routine stuff needed..

I can see I'm talking to the 'it just can't be done" crowd. That foolish wheel invention will never catch on either! If these diesel engines came with self cleaning heat exchangers from the start, you would never have known the difference but since you know one way of doing something clearly in your mind there will never be a deviation from that course. Are you really pissed off about boats that have bow thrusters? What about electronic chartplotters over dead reckoning navigation? Still use a sounding lead over the electronic depth finder? Those new fangled things just aren't reliable! Going with your idea of the routine stuff, maybe you should remove the float switches and bilge pumps and pay someone to come down and check the bilges and pump them manually when necessary.

The whole concept of progress is missed when you don't realize invention and innovation let you do more things in less time and with less effort. When I invent the self cleaning heat exchanger, Ill let you be the first customer

[GJH]

Of course it can be done, that's not the issue. But the risk/reward ratio is way out of balance in my opinion, but I have been wrong about a lot of things over the course of my life.

Most of the engines we have here are turbo charged, so what of the after/intercoolers?

Why, in the entire history of marine diesel engines, hasn't an engine manufacturer recommended (and installed easy to use valves) draining the raw water side after every use?

By all means go ahead and install this on your boat and report back to us. Someone has to go first, why not the inventor?