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Is Open Cooling system a Deal Breaker ?


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HI,

I went down yesterday for A survey, motor diagnostic, and sea test of a '08 256 SSI with 496 Volvo Open cooling system 375 hp motor. I didn't realize it was open cooling system.

The boat is in impeccable condition inside and out. The motor looks like factory new. The out drive and props look new. It has 48 hours on it, and has been on a lift in the bay in Ocean City Md. There is no bottom paint on her either. The mechanic did a compression test, extracted oil for diagnostics, and I don't have the results in hand, but he said everything was perfect.

We dunked her in the water, and she purred like a kitten. When given a little gas, she jumped out of the water and on plane quickly. It was a little choppy, but felt as smooth as butter. With 5 adults on board, and 3/4 tank of gas, we were able to get 61 mph on the speedometer. The power steering makes turning a pleasure.

We drove around for a bout 15 minutes. Stopped a few times for the mechanic to make a few checks, then headed back to the dock.

After having a lengthy talk with the mechanic, he explained that although a closed system would be more desirable, in 20 years of servicing boats, he as never changed a motor just due to salt being in an open system, for closed systems can get anti freeze in the motor and it does the same damage. Unfortunately, there is no way to look inside the motor to see if there is any corosion, but from the looks of the rest of the boat, the previous (1) owner is very meticulous.

Is this a deal breaker in your opinion ? How many boats out there have open cooling systems that dont have problems as long as rinsed thoroughly after use ?

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There used to be a argument about the good & bad of using a boat lift. As that would cause more or less corrosion / rusting when the air circulated thru the drained raw water passages.

My old mind can not recall the correct answer.

A accurate & correct temperature thermostat is VERY important to prevent building up salt deposits .

Cold engines, low salt build up & black plugs & transom. Can only go so high on plug heat ranges.

Hot engines, fast salt buildup & clean plugs & transom.

Medication is after me.

Trust the mechanic.

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This should not be a problem. A thorough rinsing/flushing after use should be fine. Lots of boats in saltwater use open systems. With and outdirve or standard inboard, a residual amount of water remains in the manifold, risers and cooling lines. if it is saltwater, it accelerates corrosion and shortens the life of the cooling system. Obviously, if left unattended to, it will cause overheating problems that will ultimately damage the engine. Worst case for you, since the boat is very young is that you will have to replace manifolds and risers more often than with the closed system. BTW, the closed system uses seawater to keep cool. This would not stop me from buying the boat.

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Not a dealbreaker at all, in my opinion. My boat (raw water cooled), is 10 years of straight salt use with regular flushing after every use. I have my original manifolds, my engine runs steady at 160 degrees (even after a hard full throttle blast), and, according to my mechanic, the manifolds and risers look fine and did not need changing when I had the motor out two months ago for an oil pan change. Flushing makes all the difference, so I'm told (and the evidence supports with my boat). That 256 sounds like a very nice boat.

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I agree... Our 2007 Maxum 2400SC didnt have closed cooling... We just made sure flushed after salt water use .... & you can always add closed cooling if ya want.... A friend just bought a 2005 Doral Monticello out go Santa Barbara ... Only has 180 hrs on her ... & is raw water cooled. He is gonna add the closed cooling system to it.

Cheers !

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I would add the closed system!! But first I would pull the Tstat to see how much rust in in there. If theres too much it will clog the heat exchanger. I have added them to my 2 past boats but both had under 20hrs on them.

For me, I would not buy a boat with out a full closed system. But thats me! The engine will last longer, less work in the fall and the boat will hold its $$$ more.

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I'd still go for it. I had 4 previous boats that were raw water cooled and never had any issues with any of them. One was run exclusively in the salt water of the Jersey Shore. Closed cooling is a nice feature but I wouldn't call it a deal breaker.

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I thought with the Volvo 8.1 the engine was closed. ? The raw water only cooled the exhaust and power steering? At least that is what i was told by a dealer. Being a habitual flusher it doesn't worry me that much, especially with those hours. I have been trying very hard to find a fresh water boat as I am also in Ocean City. Only because i don't want to buy corrosion but i am not worried down the road as i flush everytime it leaves the lift. I have to admit though , as of yesterday i am giving up the freshwater fight. The boat in Atlanta is just a little to rough and some of the people there make it to difficult. Their are a million boats out there living in salt. In slips, never flushed, going to 2,000 hours before internal engine issues.

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To build on my earlier post: I would want closed cooling on any boat that is stored in the salt without the ability to flush the motor. For any boat that is pulled and can be flushed, it does not seem as necessary. There are two types of closed systems. Some use a closed loop for the engine only, some include the manifolds. Either way, the heat exchanger, raw water pump and drive are still circulating saltwater, and maybe the manifolds. I looked into a closed system for my boat when I got it, and was advised that it wouldn't really buy me anything, because my boat is stored dry and I flush it anyway (why leave the heat exchanger and drive filled with saltwater if you don't have to?). Again, if the boat is slipped in the salt water, closed loop is the way to go, for sure.

Depending on what type of system you get for the 256, if you decide to, expect to spend one to two large herd of deer.

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I think most all say they do, but I question if every marina does well enough or every time. A friend in my local squadron just replaced the risers and manifolds on his Volvo that is only about 5 years old and always rack stored. They were very clogged and the engine was overheating. He has about 300 hours, if I remember right. To me, that seems too soon for an engine that was supposedly always flushed. If it were my boat I would stay around long enough to see it being done, or do it yourself.

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A half system kit is around 700 to 800 and a full kit is about 900 to 1000 depending on the engine. The kits are not hard to install. About 4 to 6 hours if you never done it before.

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Scaling / build up, is very dependant on the minerals in the water & engine temperature. Mucky dock areas can do a number also.

Add muck, minerals & a small waterflow while near idle rpms & buildup can be faster than expected.

St. Lawrence River between USA & Canada. Friend is always in mucky docking water. When he gets in clean stuff he revs it up & blows a browm plume behind him.

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I would not add a closed system to a boat that was in saltwater. There will be some rust that could easily clog the heat exchanger. I have an open system - would I prefer a closed system? Yes. Would it stop me from buying the boat - No. If in salt, I would change the risers and manifolds every 5 to 6 years regardless of flushing and hours of use.

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