Indigo FWC

[alcodiesel]

10-4, thank you Neil.

My son and I installed it today, minus the wiring. Had a great dad n lad time working together listening to Christmas music then Led Zeppelin. Nice mix. Of course he gets lunch out of the deal- that's the rules, right?

Everything went together easily. I had studied Tom's instructions, measured for all the plumbing yesterday and got $47 worth of heater hoses today.

[Marty Levenson]

Location?

Wondering where you mounted the HX? On our Tartan 27 I put it in the starboard sail locker.

Don't forget to keep an eye on the HX pencil zinc - had quite a hassle replacing mine after neglecting it for a few years.

[joe_db]

WARNING!
Bleeding the air out of the system with the electric pump is about 20 times harder than you think. It is very easy to get some circulation that will hold temp at idle and still have air pockets that will cause the engine to overheat badly under load.
Run a jumper so you can use the pump with the ignition off and run with the heat exchanger cap off until all the air is bled. I had a couple of air bleed valves that helped a lot.

[thatch]

Hose Size

Alcodiesel, Out of curiosity, what are the hose sizes on the coolant and raw water sides?.
Tom

[alcodiesel]

To answer your ?s:
The HX is in the lazerette. Hoses: seawater-5/8, coolant- 3/4 and pressure gauge to the diverter 1/2
The pump is in a locker next to the engine and is about 3 feet lower than the HX.
This thing takes hardly any effort to bleed. The pump shuts down when the impeller is dry then restarts a few seconds later. I'm adding water at the HX as the air is bubbles out. I did this several times during my testing.

Today was an all in test:
The cooling water was cloudy at worst, nothing large enough to get caught in the filter so I removed it.

I ran the A4 at 1000rpm with a barnacled prop engaged ( big load) for 15 min. the temp was 100- barely off the pin.

I'm sitting in the cockpit in the sun just listening. Then the engine sputtered once. I look at the temp- 200!

I slowed to idle, disengage the prop and shut down. Turns out the jumper I had on the pump lead fell off.

I re connected it, restarted, engaged prop, went to 1k rpm again and it cooled off quickly (like a minute)to 120 and stayed there till I shut down 10 mins later.

I'd say this test was a success, especially it's ability to cool off while under load.

[toddster]

Nice. Does the kit not come with an expansion tank? The cobbled-up FWC in my boat didn’t have one and HX just overflowed to the bilge, requiring daily topping-up. Just one of many weird PO tricks.

I too moved the HX to the sail locker. Actually, I installed a water heater outboard of the standpipe and the HX and expansion tank aft of that. It’s easy to open the locker and do a quick visual inspection of coolant level in the translucent exp tank.

Strangely, I seem to go through a (NAPA) pressure cap almost every season. It’s like the cap is more sacrificial than the zinc. Someday I’ll have to sit down and think about that...

[joe_db]

FYI - 1000 RPM is not that big a load. Did you try running flat out for an hour?

[Dave Neptune]

Be sure

Bill, if you are checking the performance of the cooling system then test it under a cruising load.

AND be sure that the engine box is closed as a lot of heat radiates out when open adding to the cooling and it is gone when the box is closed. I have been on boats (power & sail) when cooling starts to be an issue as the temps were rising. In many cases when we opened the engine(s) up to the open air we could run a few hundred more RPM's and stay cooler than when closed.

Dave Neptune

[ndutton]

While absolutely true you want to test at full cruising speed, you also want to crank it up to wide open throttle for a while. If you ever need to push it that hard you'll want to know what to expect. Temps will be higher, guaranteed.

[alcodiesel]

Oh yeah, I concur on the full load test. That's coming.

I am still getting too much pressure on the coolant circuit (14psi), like there's a blockage somewhere. Yet when I pull off the hose from the manifold exit it really blasts the water out. It's a work in progress.

I am not in a huge rush as the boat is still mast-less. Now the holidays are getting in the way of the rigger finishing the job.

[joe_db]

14 PSI would blow right past the cap on my HX. Is that cold?
Also watch for side effects from a hotter engine. You can run a glycol mix to at least 220 degrees, but that much heat may cause other issues. In my case steady running at 180 causes vapor lock issues after a couple of hours, which is why for now I am back to RWC.

[ndutton]

14# sounds like something's constipated.

[joe_db]

14# sounds like something's constipated.

My 3 guesses:
1. The side plate injector.
2. Thermostat housing and related fittings.
3. The manifold.

[ndutton]

My 3 guesses:
1. The side plate injector.
2. Thermostat housing and related fittings.
3. The manifold.

. . . . or any combination thereof.

Bill, I did not read where you took any measures to enlarge or clean out the coolant passages as part of this installation. Also, what is the current thermostat/bypass configuration?

[alcodiesel]

Tom came down yesterday and we experimented with regards to lowering the pressure.
We tried:
With and without the thermostat (MMI), with and without the bypass valve (MMI), larger (5/8) thermostat housing to manifold hose and fittings, circumvent the manifold all together.

Lowered the psi a pound or two at best.

So far conclusions: the main restriction is T inlet (which also has a hole directed between #2 and 3 cyl.), all the fittings and hoses add up. The 14psi appears to be on the injector T not anywhere else.

Results thus far: There is good flow and we did 2 full power runs (1600rpm) for half an hr each 165 to 170 was highest temp. The thermostat hardly opened but when it did the delta P was - 1/2 psi. Yes the box was open. Yes the prop is barnacled up and yes tied to the dock(good load), and yes the bay water is cooler than in the summer.

BTW: purging that air from this is very easy. The pump shuts down temporarily when it cavitates. Adding water to the HX while it does that, it takes about 30 seconds to a minute before all the air is out. I think having the HX 3 feet+ above the pump and no dips or valleys in the hose runs helps.

This is a new head and while I replaced it I cleaned all passages and the side cooling plenum (or whatever it is called). All new hoses.

I hope I answered all questions in my write up and faithfully described our attempts to discover where the high pressure is coming from.

Now the great news: the rigger said he'd most likely install the new mast (and all new rigging) Friday. Still a hope I'll be sailing again by New Years.