Another electric FWC system installed

[sailbristol]

nice but

very nice clean setup but I see two potential problems
the clear hose on the pump is only rated for 150 degree water
the pump is in wrong orentation they suggest either horizontal or vertical with motor up not down as you have

[ndutton]

Thanks sailbristol but not to worry, things are a changin'.

I'm posting this a little early as I have little real information but yesterday I tested the system for the first time and the cooling capacity of the HX is insufficient. It's a single pass exchanger. I had a nagging concern when I first realized it but figured I'd give it a try anyway. You'll see in my posts a recurring theme of "Let's see if it works."

Other than that, everything else worked beautifully, electric pump had excellent flow, header tank position and plumbing functioned well, the entire system purged itself of air easily. I'll be testing a borrowed HX this week and pending a successful test, will be shopping for a multi-pass HX. Everything I've seen so far will have the pump mounted differently and because of that there will no longer be a concern over an air pocket at the pump, the reason for the clear hose in the first place. And frankly, I wasn't expecting temps over 160 anyway.

Too bad, that stainless HX sure was purdy.

[ndutton]

Update

Replaced the HX with a borrowed one and ran her up at the slip with some moderate alternator load and no thermostat. Temp never exceeded 140 so the original stainless HX is confirmed to be of insufficient capacity. Of particular note is the performance of the Mustang supercharger intercooler electric pump, couldn't be happier.

Just now pulled the trigger on a new Sendure HX. Update to follow when there's something to report.

[ndutton]

Follow-up

Electric FWC system is complete and tested, works great. I had my share of problems but they were easily resolved thanks to the generous help of a listmate both with the loan of a heat exchanger for testing and as a sounding board. You know who you are, my deepest thanks. Fortunately none of the tweaks required a departure from the original design. Here's the latest:

1. My original stainless heat exchanger was a single pass type and didn't have enough thermal exchange capacity. Installed and tested, it ran up to 200.
2. I installed and tested a borrowed 2 pass exchanger, engine ran at 140, solid as a rock.
3. Purchased a 2 pass exchanger, modified the fittings slightly, painted it up (presentation is everything) and installed it Sunday. Started the engine to test, engine died after 60 seconds.
4. Pulled the carb, brought it home and cleaned it up (hadn't been done in at least 2 years), re-installed it tonight, primed the bowl and started the engine. Ran for 60 seconds and died.
5. Primed the bowl again, started the engine, ran for 60 seconds and died. Y'know, it's a sign of mental illness when you repeat the same action and expect a different result but man, all I wanted to do was test my new FWC!!
6. Jumpered the oil pressure safety switch (electric fuel pump) and started her up, ran smooth at the slip for an hour. Oil pressure gauge read normal. Running problem solved.
7. Running at the slip with moderate alternator load, temp never went above 120 during the hour, exhaust manifold, heat exchanger and hoses were only warm to the touch, infrared thermometer read around 117 on the manifold and hoses, 95 on the HX shell, 45 on the bottle of beer. Cross another project off the list.

Didn't have the camera with me at the boat but here are some pics of the replacement exchanger prior to installation.

[Administrator]

Way to go, Neil!

When the dust settles, would you consider posting the make, model, dimensions, etc. for the single pass HX? Sometimes, it just as important to know what didn't work as it is to know what did.

Bill

[ndutton]

We learn more from our failures

The single pass exchanger was an absolutely gorgeous fabrication of unknown origin. I found it on eBay for $75 and after learning it was unsatisfactory, sold it on eBay in 4 hours for $75. The gentleman who bought it is using it in a chemical process, I suspect that was the intent of the design in the first place.

As I said in a previous post, neither the Moyer nor Indigo systems would work for me due to zero clearance at the flywheel and a water heater in the loop mounted higher than the engine. Because of that I was left to my own devices to assemble a system. For those in a similar position, an important feature in selecting an exchanger besides the multiple pass design is the internal tube bundle. It's common in engine type exchangers, not so in others. My original exchanger didn't have the tube bundle and that should have been a red flag right there. I treated it as a yellow flag and although it didn't cost me any additional money it did add about three weeks to the project finding and installing a replacement.

Here's a pic of the unsatisfactory exchanger. There were no markings on it anywhere but it had the look of professional manufacture, certainly not home grown.

[ATTACH]4721[/ATTACH]

The dimensions were similar to other exchangers used successfully on A-4's. 3" diameter x approx. 16" length. I learned the hard way that what goes on inside means more than dimension.

[sastanley]

Oooo..nice!

Neil, looking good..

For those of us stumbling down this same road, what are the hose & fitting sizes you were able to get on the installed HX? I know we've discussed some data offline that you thought at least 1/2" NPT as the minimum (I've had plenty of success locating reasonably priced HX's with 3/8" NPT ) - but I also know you have the out-of-the-ordinary hot water loop in yours too. So, I was just curious what yours ended up being...hard to tell from the pics since there isn't really a good frame of reference.
My current thought is that I'd like to go 1/2" NPT & 5/8" hose wherever possible.

[ndutton]

All hoses, both salt and fresh water, are 5/8" with one exception - the hose from the electric pump discharge to the sideplate Tee is 3/4". The raw water pump and header tank fittings are 3/8" NPT x 5/8" hose barb. Manifold elbows are 1/2" NPT x 5/8" hose barb. The exchanger came with 1" copper elbows on the FW side and 1/2" elbows on the RW side. I kept the 1/2" RW elbows as they were a perfect fit for 5/8" hose. I reduced the FW elbows to fit either the electric pump (1/2" NPT) or water heater hose (5/8").

Based on previous flow testing and this installation process I would consider 3/8" NPT and 5/8" hose minimum sizes for electric FWC. I have numerous 3/8" NPT fittings and a long water heater loop in the system and I'm very satisfied with my coolant flow rate. You won't have the water heater loop so you should be even better off.

You may recall that I was holding out the option of an additional electric pump to boost the flow through the water heater loop. As of right now there's no need, excellent flow with the single pump and the fitting sizes as noted.

edit:
As this electric FWC concept is relatively new, until we have decades of reliable pump operation behind us I feel rather strongly that a complete and proper electric FWC system includes carrying a spare pump onboard.

[ndutton]

Here's an updated drawing with the new exchanger.

[ATTACH]4724[/ATTACH]

edit:
and a couple of pictures

[ndutton]

It's a Wrap

I went sailing today and put the new electric FWC system to the test. 6.3 knots at 2000 RPM and temp rock solid at 180. Couldn't be happier.

[roadnsky]

Congrats Neil! Beautiful job.
I'll follow your lead if I ever get back to the coast...

[joe_db]

I think I was first with electric cooling by a few years.
This was around 1994 or so:
I needed to get to Annapolis to pick up a date and my cooling pump died. Not wanting to risk the wrath of a women scorned (or at least left waiting at the seawall), I did a quick hose-monster conversion of the anchor washdown pump to a cooling pump and off I went It actually worked fairly well, but you had to watch the temp. The pump seemed to have the right flow for about 2/3s power.
Also don't forget to turn it OFF after shutdown or

BTW - anyone using an oil cooler?

[hanleyclifford]

Funny you should mention that. I have my washdown pump plumbed in with a "T" for just that eventuality.