The Fresh Water Cooling Kits Arrived Today !!!

a. k. a. closed cooling system.

2 big boxes awaited me when I arrived home today. My FWC kits for the Mercruiser 7.4's . . . they were a little heavy . . . 60 lbs. each.



Of course, I had to open them up and take a peek at the parts and instructions . . .



These kits are the 'Full' system kits from San Juan Engineering . . . They cool both the engine and the manifolds. So, this should give my engines some longevity in the salt water.

A nice thing about the engines that I have is that the elbows are stainless steel . . . so coolant will be running through the iron exhaust manifolds and sea water running out the SS elbows.

This project will have to wait a week or so, as I am headed to Seattle on business next week.

Re: The Fresh Water Cooling Kits Arrived Today !!!

I just bought an old boat that came with a brand new Sea Kamp FW full cooling system in it. As you said, the only seawater contact is through the riser on the way out. Nice. It appears to work well, as my motor runs a cool 160 degrees. I'd have to say that I'll be doing this conversion on any future motor, especially if the boat will sit in the water.

Re: The Fresh Water Cooling Kits Arrived Today !!!

Yes, my previous experience with a 7.4L engine is that the heads started to rust through around the valve guides after 21 years in salt water. These (new-to-me) engines have only been in fresh water so far, so I figured that a full FWC system would be the way to go.

For the installation process . . . I am wondering if I should install the kits one engine at a time, figuring the second one will go faster than the first . . . or . . . just do them both step-by-step so that they are done together. Not sure what difference it would make???

Re: The Fresh Water Cooling Kits Arrived Today !!!

I started working on installing the FWC kits this weekend. It was a bit tedious and the instructions were a bit vague in places.

I worked both Saturday and Sunday, and have 1 engine almost complete and the other has some work done.

Here are some pics of the weekend.

There is a fair amount of work that needs to be done in the water pump area. I actually had to remove the water pump to get some of the fittings installed.



Here is the front of the engine prepped and put back together.



Then there is this big mounting bracket . . . I was short 1 bolt in the kit . . . so off to the hardware store i went . . .



Then I had to remove the exhaust elbows, because these are "Full system" kits, and place a separating gasket between that exhaust manifold and the elbow. There was also a hex plug that had to be removed and replace with a fitting for the return water lines. Of course, I did not have the proper hex bit for my socket set . . . soooo, it was off the the Auto Parts store to get a hex bit set.

There is a picture of the elbows back on and the heat exchanger installed.



The instructions said to cut the intake hose and the recirculating pump hose so that they can connect to the heat exchanger. Then it was a matter of running the remaining hoses. At that point I was having a tough time routing the hoses where they are supposed to go, it was getting dark, etc.

So, I was hoping to get both engines done this weekend . . . it looks like I have another weekend worth of work ahead of me . . . still.

I hope the systems work well. these engines have only been in fresh water (16 years, 740 hours) . . . and they were really easy to work on . . . bolts loosened up easily, etc. The internal water passages looked to be in great shape.

I also have 2 nice thermostat housings that I can sell on eBay or Craigslist . . .

Re: The Fresh Water Cooling Kits Arrived Today !!!

I got the cooling kits installed on both engines yesterday while waiting for Hurricane T.S Sandy to arrive.

Here is a photo of the Port engine all done.



The installation instructions were a little vague to say the least, so I had to figure some detail things out that were omitted. So, I spent about 12 hours total on the Ports engine and then knocked off the starboard engine in about 4 hours.

I am wondering if I should send the manufacturer a re-write of their instruction guide???

Each engine took about 6 gallons of coolant at a 50/50 mix. I noticed some temperature issues during my testing of the system that I posted on another thread (thermostat question). So I think that I will need to do some tinkering and testing before launching the boat next Spring.

Re: The Fresh Water Cooling Kits Arrived Today !!!

tpenfield said:

I noticed some temperature issues during my testing of the system that I posted on another thread (thermostat question). So I think that I will need to do some tinkering and testing before launching the boat next Spring.

Click to expand...

Very nice write up. I have no direct experience with these kind of kits, but could the temp. issue be due to air in the system somewhere? perhaps try running the engine with the coolant tank cap off and squeeze the coolant lines to see if you can work any air out?

Re: The Fresh Water Cooling Kits Arrived Today !!!

Thanks for your kind words.

The system took 6 gallons of coolant, which is right about what I figured. So, maybe a small amount of air, but not much.

I did initially run the engine with the cap off to see if I could get it to burp, and it did a little bit. So, we shall see how the engine runs on a repeated basis and if it sucks in appreciable amounts of anti-freeze from the reservoir as it cools down, etc.

Re: The Fresh Water Cooling Kits Arrived Today !!!

Update to Closed Cooling Installation . . .

I had a few things that I wanted to do to finish off the new cooling system before the season starts. So, today was the day . . .

I got 2 sea water strainers to filter out marine life, etc from the intake water. I used a sea water strainer on my last boat (which was raw water cooled) and noticed that the impeller suffered little/no damage over the course of a season. I was easily getting 3-4 seasons out of an impeller with the strainer. The new heat exchangers would also have better longevity with a strainer.



I had to shorten the intake hoses by the length of the stainer fitting distance . . . and also removed the fresh water flush kit, since it would no longer be used. When I removed the port side plumbing, I found this. . . interesting application for a spark plug . . .


The starboard side installation was pretty easy . . . the port side engine was a bit tougher, because the engines are quite close to each other . . . only about 2" between the exhaust manifolds . . Here are some pics of the sea water strainers installed. So, everything is new for the cooling systems . . . pump body, impellers, cooling system ,etc.


Then I had to fix an issue that I had with the starboard side engine in the area of the recirculating hose. I was supposed to route a 1" hose to a lower fitting on the recirculating pump . . . but I could not get the plug out of the pump body. So, I fabricated a "T" fitting for the large recirculating hose from some copper pipe. Here is a picture of the new fitting/junction installed.
I'll need to wait to start the engines and give everything a final test and check before launching. It still is getting to and below freezing around here . . . so maybe in another month.

Re: The Fresh Water Cooling Kits Arrived Today !!!

Ayuh,.... Lookin' Good, Ted,.... Interestin' Plug ya found,....

Re: The Fresh Water Cooling Kits Arrived Today !!!

Bond-o said:

Ayuh,.... Lookin' Good, Ted,.... Interestin' Plug ya found,....

Click to expand...

Yes. interesting . . . I am still trying to figure out why the hose was there to begin with and why it needed to be plugged

Maybe it was something that ties the 2 engine flush systems together :noidea:

Re: The Fresh Water Cooling Kits Arrived Today !!!

I'm taking the week off from work. So, I have been finishing off a few boat projects . . .

I finally finished off the closed cooling system project by mounting the coolant overflow tanks. I realized that there is a 1" thick mounting surface on the hull sides inside the engine compartment :frusty: . Not sure why I had not though of it before . . . I found an open spot on each side . . .



So, this should finish this project off. Just waiting for the weather to warm up so I can do some test running of the engines, etc.

Re: The Fresh Water Cooling Kits Arrived Today !!!

tpenfield said:

I hope the systems work well. these engines have only been in fresh water (16 years, 740 hours) . . . and they were really easy to work on . . . bolts loosened up easily, etc. The internal water passages looked to be in great shape.

I also have 2 nice thermostat housings that I can sell on eBay or Craigslist . . .

Click to expand...

Ted, Mine only had 122 hrs on the clock but was 10 years old.

One the things I did was remove the core plugs in my 454 and remove a LOT of loose rust and sand from the block. I also removed a fair amount of loose rust from the manifolds. (did you replace your manifolds?)

By the color, it looks like you used DEXCOOL? (so did I.....it's been in there since 2006)

I have noticed (for winterization) that the only place water pools is the hose that runs under the block (yours is different I presume because you have a cool fuel system?)

I am going to put a "TEE" and PVC ball valve in the hose that runs under the block so that I only need to open the valve to drain the lowest point. The heat exchanger and PS cooler (if not level) drain completely by themselves.

T-stat housing sold on ebay for $53!!

The engine runs 160-180 in 80+ degree water.

Cheers,


Rick

Re: The Fresh Water Cooling Kits Arrived Today !!!

Hi Rick:

The PO put new Mercruiser manifolds on as part of the purchase. The elbows are stainless steel. The closed cooling system includes the manifolds, so there is a separating gasket between the manifold and elbow.

The antifreeze looks a different color in the overflow containers for some reason . . . it is basically yellow . . . I think I might have got some dirty water mixed in or something . . . :noidea:

At some point I might pop one of the core plugs on the engines, just to see how much sediment is in there. I did that on my previous boat/engine, and the water passages were about 1/3 full of sediment, but it was a salt water boat . . .

I still got those t-stat housings . . . so maybe I can sell them on eBay. for about $50 each. :thumb:

Re: The Fresh Water Cooling Kits Arrived Today !!!

The antifreeze looks a different color in the overflow containers for some reason . . . it is basically yellow . . . I think I might have got some dirty water mixed in or something . . . :noidea:

Click to expand...

It's very likely rust.

At some point I might pop one of the core plugs on the engines, just to see how much sediment is in there. I did that on my previous boat/engine, and the water passages were about 1/3 full of sediment, but it was a salt water boat . . .

Click to expand...

I was amazed at how much came out of the block! You might want to do it sooner than later......if you plug up a heat exchanger, it'll be very hard to clear out the "stuff"

I still got those t-stat housings . . . so maybe I can sell them on eBay. for about $50 each. :thumb:

Click to expand...

I think you can. Just don't list them at the same time......... sell one and wait a while before you put the other one on there. You don't want to compete against yourself!!

I actually got more for my old OMC 460 T-stat housing!