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Zinger
10-23-2008, 12:29 AM
Hello All,:pimp::wrench:

I need to replace my heat exchanger and was wondering if I should replace it or not. I run both salt and fresh water but flush after every use. What's some opinions Thanks :worthy:

gcarter
10-23-2008, 07:01 AM
In this group of boaters, the vote and suggestions will split right along their current decisions in their own boats.
I vote for closed cooling...always.
IMHO, the benifits far outweigh the negatives.

MOP
10-23-2008, 07:02 AM
Jeff you are hooked on getting the most out of your setup, there is -0- question that higher temps produce better all around performance. On another note IMO any engine that has had $$$ put into it should be F/W cooled to protect the investment. Guys that run in fresh water can run higher temp Tstats and achieve the same results, they should however run pressure relief valve to keep the head gaskets in tact the system pressures get very high at speed. Randy may chime in with a little more.

Phil

Ghost
10-23-2008, 08:00 AM
Putting my vote in for closed cooling (mine are half systems, not full). At the same time, I don't have anything pushing high performance, but as was was noted above, if you do, you might want closed cooling to protect the investment.

BigGrizzly
10-23-2008, 08:35 AM
Here I come. First a big block chevy suffers from unequal heat dissipation on the left and right banks with a cross over. This is fact, not fiction. With a closed system most if not all that problem goes away. My engine originally, had a crossover and had a restricter in one side but that was still not great. 4 hours on the dyno to get the most balanced system. That motor did come apart because of a valve problem, or hot spot. Next we did it again with a closed system and that was 800 hours ago,knock on wood. Other advantages id faster more controlled heat up and slower cool down which reduces thermo-shock. even with with a t-stat when you slow down with a crossover the block stays hot and then the cold water enters, getting the picture. Now a circulating pump is a little better. Now you guys who have stock motors, you don't have to run out and buy a closed system. now if you re engine do it! Wipple and procharger tells you not to put in a t-stat, because people are stupid. I have a 165 in my procharged unit because I run lean compared to most engine builders. This gives me a buffer in case I miss looking at the gauge. With a blower detonation happens in a hurry. At the time I put this together no one would close cool an engine with over 500 HP. I said why not cars do it. So here I am a closed cooled 690Hp blown engine, not the fastest but darn fast. One other small advantage is fuel economy rivals or betters stock configurations. It is a known fact that cold engines ware faster. GM did the graph and below 150 deg ware increases by 40%. Before you salt water guys jump in with the 140 degree salt crystallizing thing two things. 1) a full system does not have ANY raw water running through the exhaust. 2) A half system the exhaust water isn't hot enoygh nor stagnate enough to cause it. BTW The Corsican runs at a much higher temp because it is not blown. In the end you should close cool it. All the new motors are going that way. Anybody seen a new 496 without it.

VetteLT193
10-23-2008, 09:22 AM
On a trailer boat it's not worth the weight, complexity, or expense...

A boat that sits in the water it's a must.

If I was in your shoes I'd probably just buy a new heat exchanger... it's already set up for it and it might cost you almost as much removing it... it also seems FWC boats do pull a few more bucks in re-sale, especially salt water boats.

MOP
10-23-2008, 09:55 AM
On a trailer boat it's not worth the weight, complexity, or expense...
A boat that sits in the water it's a must.
If I was in your shoes I'd probably just buy a new heat exchanger... it's already set up for it and it might cost you almost as much removing it... it also seems FWC boats do pull a few more bucks in re-sale, especially salt water boats.

Being an old fart boat mechanic I totally disagree with the trailer statement, I trailer and no way would I be without it! The pluses out weigh the minuses. More power, better economy, better internal engine tolerances means less wear, much less stress on head gaskets and the big two no worries about blocks freezing and no corrosion with in the block. Add all those facts up and the initial cost disappears in longevity!

BigGrizzly
10-23-2008, 10:27 AM
As for weight My entire add on is just under 50 pounds. If you have a circulating pump and all but crossovers have one the addition is only a heat exchanger and an expansion tank. Knowing that that would be a big issue on the board I weighed all the parts. At The Fort Walton rally , I pulled the Criterion out and parked it, no flush, no worries. Two days after while I was home I washed it and ran it for 5 minutes. With my system I don't even have to run it, I just plug in the hose and turn it on.

VetteLT193
10-23-2008, 10:53 AM
Being an old fart boat mechanic I totally disagree with the trailer statement, I trailer and no way would I be without it! The pluses out weigh the minuses. More power, better economy, better internal engine tolerances means less wear, much less stress on head gaskets and the big two no worries about blocks freezing and no corrosion with in the block. Add all those facts up and the initial cost disappears in longevity!

you have to understand I live in Florida. It only freezes a couple nights a year where I live and the water temp doesn't fluctuate a whole lot either. For a northern boater you make a good point and it is something well worth weighing in on the decision.

As far as more power and better economy... I have yet to see that in practical use. Higher temperature engines have more power only if the intake air temperature remains constant... but it does not, air temp goes up as engine temp goes up and many times it means a net loss in power... this has been proven time and time again on dynos. It is one of the reasons why many aftermarket computer reprogramming units work in conjunction with a lower T-stat.

I understand the pluses of using closed cooling, but still can't personally justify it for a regular summer use trailer boat that is well treated, flushed, etc. It is just one more thing to deal with :nilly: I do understand others see it as one less thing to deal with

BigGrizzly
10-23-2008, 12:24 PM
Vette we seem to disagree gain. I have gotten consistently over 3 mpg. At rallys. I consistently put less fuel in mine than any other bbc that has traveled the same distance. Since I have a fuel flow meter On my boat, I really DO know the answers. I have proven this time and time again on the dyno. Air temperature is constant for that day. One other small fact is since I worked for an auto manufacturer, we have proven it on EPA test, Why do you think all later model cars run higher temperatures. They all have redesigned the cooling systems to run higher temperatures. Automobiles have the same air the boat has on any given day. I can see your not wanting to put one on your boat, $ and time.

gcarter
10-23-2008, 06:49 PM
Vette we seem to disagree gain. I have gotten consistently over 3 mpg. At rallys. I consistently put less fuel in mine than any other bbc that has traveled the same distance. Since I have a fuel flow meter On my boat, I really DO know the answers. I have proven this time and time again on the dyno. Air temperature is constant for that day. One other small fact is since I worked for an auto manufacturer, we have proven it on EPA test, Why do you think all later model cars run higher temperatures. They all have redesigned the cooling systems to run higher temperatures. Automobiles have the same air the boat has on any given day. I can see your not wanting to put one on your boat, $ and time.
My Minx got just under 4 MPG. This gave me a really good range.
The TR will be Closed also.
I can't wait to get the money together to fulfill my plans.

zimm17
10-24-2008, 09:22 AM
Closed loop for me too. If you go in salt- run one. Lake/river boat- raw water is ok.

maddad
10-24-2008, 10:23 AM
Closed cooling does offer some real power pluses. Raw water cooling is as simple and uncluttered as it gets. I use the raw water and know my motor will never last long enough to rot away from the inside. Not the way I use it.:shades:

zelatore
10-24-2008, 12:18 PM
You'd be a fool to remove the closed cooling system.

If you didn't have it and wanted to stay raw water, that's one thing. But to take it off? No way.

ANY boat that sees salt NEEDS closed cooling. There's a reason most engine makers don't even offer raw water cooled engines for big boats these days, weather your talking gas (merc, volvo, or crusader) or diesel.

My 22 doesn't have it. I'm not running out to add it, but it's not used in salt and it lives on a trailer and has a flush so it's easy to deal with. My Carver (and every boat we sell new) has a closed system. I wouldn't have bought it without it.

BigGrizzly
10-24-2008, 12:30 PM
I have been using closed cooling for 40 years. In fact when I bough the Criterion and it did not have it I almost ran out and did it. Since I knew I was going to re engine it, I waited. When it came time with aluminum heads and intake I decided to make it happen. After playing with the dyno it was a no brainier, it was the only way to go.

NLMO
12-05-2008, 01:31 PM
I have been using closed cooling for 40 years. In fact when I bough the Criterion and it did not have it I almost ran out and did it. Since I knew I was going to re engine it, I waited. When it came time with aluminum heads and intake I decided to make it happen. After playing with the dyno it was a no brainier, it was the only way to go.
Mr. Big Grizzly et all,
How complex was it plumbing and relocating the closed loop cooling with the procharger/intercooler on the critter. I have a 454 MAG/MPI 22 Classic with an add on closed loop cooling system, the heat exchanger hangs off the front off the engine. I am considering a procharger set up but it looks like the procharger system swallows up all the real estate up front, just wondering what tips or lessons you all have learned by combining the procharger and a closed loop system. Just trying to get a reality check since my 4 hour jobs usually end up being 40 hourshttp://www.donzi.net/forums/images/smilies/bonk.gif. Omar

gcarter
12-05-2008, 02:08 PM
There are a number of suppliers that offer remote mount HE's.
They can be mounted under the engine on a stringer like Zim did, or on the small transverse frame in front of the engine like Griz did. That's what I'm planning on the TR.
My boat will end up w/an extraordinarily clean engine with the HE mounted low and in front of the engine along w/the Meziere electric remote coolant pump.

Last Real Texan
12-05-2008, 02:24 PM
Hello All,:pimp::wrench:
I need to replace my heat exchanger and was wondering if I should replace it or not. I run both salt and fresh water but flush after every use. What's some opinions Thanks :worthy:
Keep it.....cheap insurance

Tex

joseph m. hahnl
12-05-2008, 02:29 PM
1) a full system does not have ANY raw water running through the exhaust. 2) A half system the exhaust water isn't hot enoygh nor stagnate enough to cause it..

A full system has coolant running through the exhaust manifolds:wink:.
The raw water enters the Risers and exits through the exhaust to escape :cool:.

A half system only has coolant in the block. The exhaust manifolds are at the mercy of the sediments


I have closed cooling:shades:. It is definitely better to have than have not:crossfing:

:mad:"Salt is evil " :mad: It never comes out:shocking: It impregnates itself to the rough surface texture and porositic nature of cast iron.
:mad:No salt ever :mad:

Donzigo
12-06-2008, 06:10 AM
I have been boating in salt water for 25 years and closed cooling is the way to go. The benefits, which have been well documented by others in the this thread, are so evident. I have FWC in the 2 496s I intalled last summer in the Z-33. It is amazing!

I have had boats that were not FWC and I much prefer the FWC.

mattyboy
12-06-2008, 07:27 AM
can't speak for closed cooling or running in salt but i can say with a raw water system in fresh water I had a 40 year old motor with the original HM crossover and HM risers and never had any corroded block or riser problems and I know it was drained for the last 15 years and the boat was a west coast boat in it's early days so i would imagine it ran in the pacific a few times before it came back east .

so worrying about the block rusting for the inside out is a very small worry, you see alot of original old classics up in lake george done the same way drained every year and still going strong

oh one more thing salt is for my pretzels not my boat ;)

BigGrizzly
12-06-2008, 08:34 AM
Well as for starters I don't have a full system. since I have ss headders corousin is not an issue in the Criterion or the Corsican. On the 16 with I don't worry about the exhaust. A quick flush and it id over. Unlike Matty I had a timing cover corrode on the 16 in less than 2 years but it stayed in salt 6 month a year. then I switched and it has been 40 years since a problem. Basically it is like swapping a radiator if yoy still have the circ pump. It will take about a weekend if you think about it and get a kit made for your engine. I had my kits made for my high out put engines special and now they are in their catalog. The Criterion was expensive but is what I wanted because nothing is on the engine. and looks normal. It is from PPM. but these guys have som less expensive ones
http://www.marineexhaustmanifolds.com/index.cfm.

Pismo
12-06-2008, 12:23 PM
Someone needs to develop totally closed cooling system like in a car or a lobster boat for a stern drive. Antifreeze and a radiator. Year round boating. Use the drive as a radiator or something. When is the last time you worried about or even thought about your car's cooling system..Boats should be the same.

gcarter
12-06-2008, 12:46 PM
If you were 100% in salt water, you could develop an internal keel cooler.
Salt water wouldn't freeze. But the same thing could be said for any kind of cooling system in salt.

Pismo
12-07-2008, 06:28 AM
Pismo, the disbursement of heat is the problem. Would you mind if there were a radiator on the top of the engine hatch? I wish I knew how to do Corel draw .......... it would be cute to see it.

I was more thinking along the lines of a a lobster boat setup where they have a totally closed antifreeze system with a radiator in the keel. Keels are big tho and lobster boats are slow so it works well. To do it on a stern drive you would have to build a long lower unit or something and pump the coolant thru it to cool. Or have some kind of totally flush radiator in the bottom of the boat or both. I'm reaching here but I'm sure it could be done somehow. Would have to work the numbers and see how much area and flow you would need. Those big blocks at 5000+ rpm make a lot of heat.

BigGrizzly
12-07-2008, 10:51 AM
pismo, the TRS drive has no water going through it at all neither does the Konrad drive. Hull coolers have been around since I can remember. I remember a Jersey Garvy with a 327 chevy with just copper pipe running down the hull and nothing else. Now I almost have it One valve and it empties the heat exchanger and exhaust at the same time as well as the water pump.

joseph m. hahnl
12-08-2008, 07:14 PM
Someone needs to develop totally closed cooling system like in a car or a lobster boat for a stern drive. Antifreeze and a radiator. Year round boating. Use the drive as a radiator or something. When is the last time you worried about or even thought about your car's cooling system..Boats should be the same.

Do you mean for the outdrive itself:confused:?????????????

Pismo
12-09-2008, 06:45 AM
Do you mean for the outdrive itself:confused:?????????????

No for the engine, put the radiator in the drive or the bottom of the boat.

joseph m. hahnl
12-09-2008, 04:54 PM
No for the engine, put the radiator in the drive or the bottom of the boat.

That's what I thought you meant:confused:. They doo: that is what we are discussing:wink:.Rather then using a radiator with air passing through they use a copper heat exchanger with raw cold water(supplied by impeller in the out drive) that runs through one chamber to cool coolant(driven by the engines water pump) that is running through another chamber and through the block (1/2 cooler) and additionally the exhaust manifold (full cooler).
It is completely closed and doesn't need draining in winter or flushing.
"Fog and your done". Although some will still run coolant Through the out drive
to purge the raw system of any residual water that may have been left behind.

The only difference between the 2 is: The full runs much hotter as the exhaust gas in the manifolds is roughly 1200F degrees. When coming off full throttle or 100 degree ++ days I will high idle @ 1200 rpm in drive a small lap to basically do a cool down.

This is what I have:shades:
http://orcamarine.thomasnet.com/viewitems/marine-cooling-system-kits/conventional-marine-cooling-system-kits?&forward=1

As far as this thread goes if your already geared up for it "as you are"
you should definitely keep it in place.

One thing that you may want to keep in mind is the boiling temperature of water to coolant. In the event that you should get an over heat:shocking:Water will form high pressure steam (212F)and could potentially pop head gaskets. Coolant is more forgiving as it has a higher boiling temp.

BigGrizzly
12-10-2008, 08:50 AM
Beem ther5e done that. there is a world of difference between the off the shelf heat exchanger and the ones for over 600 HP on a big block. My Criterion is a modern style whith what is called a full flow system. It would be hard to explain except it is a 5 pass system and very efficient, compared to most on the market. There is more to this heat exchanger when more hp is encountered.

mphatc
12-10-2008, 06:43 PM
I have a closed loop cooling system FS in the Parts FS section:
http://www.donzi.net/forums/showthread.php?t=55187

It is brand new . . . I didn't use because the boat gets fresh water use, and I had my aluminum heads coated to protect them against any corrosion.

Mario L.