Author Topic: Atomic 4 Water Heater Plumbing  (Read 3101 times)

T_schlueter

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Atomic 4 Water Heater Plumbing
« on: November 19, 2020, 10:28:19 AM »
Anyone have a water heater that operates off either engine raw water cooling or 110VAC?  The plumbing from engine to heater baffles me.  It's very hard to regulate engine temperature.  There is a gate valve with round handle that I believe is meant to control the temperature but is quite temperamental.  It's very easy for raw water to completely bypass the engine and circulate through the manifold causing overheating.  It further baffles me why the external inlet to the thermostat housing is bypassed.  Any suggestions as to how best to plumb this?  Picture attached.
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Alma

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Re: Atomic 4 Water Heater Plumbing
« Reply #1 on: November 19, 2020, 05:35:01 PM »
Yes- That is a lousy setup and restricting the output from the flexible impeller pump with that gate valve can cause the bearing in the pump to be ruined. I ruined 3 expensive pumps with that setup and even the Oberdorfer engineers were stumped. I stumbled onto the answer when I realized the wear on the bearing was exactly opposite of the vanes and cam and caused by restricting the output. Water cannot be compressed and after the threshold of elasticity of the impeller huge forces maul and gall the shaft and bronze bushing bearing. At one time I had 4 very expensive pump housings and galled shafts-

If you can afford it buy the Indigo Electronics fresh-water cooling setup that uses antifreeze and a heat exchanger. The engine will run at 180 degrees and not have the condensation issues A-4s have running at 150-160. You will also extend the use of your hot water since it will reach 180 degrees. Remember that when you open the hot tap after running an hour...

If not you'll need to get rid of that gate valve- Someone at Pearson thought it a good idea to be able to regulate the water to the water heater... It wasn't well thought out.



T_schlueter

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Re: Atomic 4 Water Heater Plumbing
« Reply #2 on: November 19, 2020, 06:02:37 PM »
That is tempting even at $725!  This boat has always been in fresh water so I may have to wait on that.  I'm also considering PSS dripless packing gland/stuffing box.  My engine is also mechanical fuel pump and points/condenser ignition both which I should upgrade.
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Alma

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Re: Atomic 4 Water Heater Plumbing
« Reply #3 on: November 22, 2020, 12:14:59 PM »
At one time a 15 years or so ago the mechanical fuel pump certification by the USCG was rescinded. Rebuild kits and new pumps became very hard to acquire.

There was concern of shore-side automotive equivalent pumps being used in boats and the automotive pumps have a vent hole that allows gasoline to drip on the road- This enabled the savvy driver to see a problem with the pump before it failed completely- Aboard a boat this fuel dripping in a closed engine compartment would be a fire hazard.

That issue isn't a problem with genuine marine grade pumps. There is no vent hole.

I was able to but a rebuild kit for my old pump and it is still in my spares locker. My original 1978 fuel pump works perfectly. It has never been modified except for paint when the engine was rebuilt.

The supplied mechanical pump is a robust, simple and safe unit. It features a 'tickler' lever that enables you to prime the fuel circuit in the Spring for first start up so you don't risk flooding the engine cylinders with seawater while waiting for fuel to arrive at the carb at first crank-  This is also helpful if you don't use the boat for a month and the fuel in the float boat evaporates- A quick couple of 'tickles' and the carb is full again and ready to start immediately.
We had some lousy HOT weather this season so ALMA sat unused for a couple weeks- That tickler enabled me to start the A-4 without shutting off the seawater intake and risking burning the cooling pump seawater impeller.

I would recommend you stick with the original fuel pump. An electric pump cannot be repaired, requires an oil pressure safety switch to prevent pumping fuel when the engine isn't turning, a fuse and busy wiring. That's at least 10 wiring crimps and lugs all of which can fail from corrosion usually at the worst possible moment.

The 'fresh water cooling' kit was about $600 20 years ago. It has performed flawlessly. The heat exchanger has been cleaned and painted several times and works perfectly.

Having a boat sailed in Fresh Water has saved your Atomic Four from internal corrosion.

A 'fresh water cooling kit's anti-freeze is even less corrosive than lake water and the big bonus for you is a hotter running engine that is more efficient and longer lasting. Again watch out for the 180 degree water in the shower and sink taps- Another bonus is a 6 gallon hot water tank will give long luxurious showers at 180 degrees.

Save the money for the electric pump and get a (pair) of Pertronix electronic ignitors. You'll want a spare.
You'll also want the matching Pertronix ignition coil. I got good deals on eBay.

I do NOT recommend the "Hot Spark" brand ignitor. I have had them fail in cars and boats. Their customer service is abysmal.

I love my PYI dripless stuffing box gland.

Originally (20 years ago) I had the original "low-speed" version and I needed to 'burp' the bellows every time I went sailing. In saltwater the same organisms that die and make sulfur smells in the head create sulfur gas that displaces the water within the bellows and that is a problem because the water cushions vibrations and cools the friction surface in the gland.

The newer PSS shaft seals all have the vent tube that allows the built up gas to escape and there is no need to 'burp' the bellows. My new one has worked perfectly this first season with the new engine.

 

T_schlueter

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Re: Atomic 4 Water Heater Plumbing
« Reply #4 on: November 22, 2020, 11:05:19 PM »
I just ran across Indigo's alternative thermostat and housing that mounts separately from my existing thermostat/housing.  It will also feed my water heater.  Looks like $150 or so. I'll call them in the morning.
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