Keel coolers etc., for Outboards I/Os ?

With an outboard or even an I/O using raw sea water to cool hot parts is not a good idea.
You plug in your fuel supply so why not plug in a keel cooler or heat exchanger
and have a long lasting efficient reliable fluid cooling system reducing constant maintenance.

 

Lots of rework for that
How do you get the air out of the high part of the engine?
What pumps it around?
Could an outboard stand to have warm water enter the engine when its designed to take ambient temp water?
You still need a total loss water to cool the exhaust.

 

Also an outboard turns to steer, you would either need a flexible joint of some kind, causing restricitions on the turning and a source of unreliablity. Or a "radiator" arrangement causing much water resistance on the outboard.
Though if you were to fit hollow steering fins either side of the prop, that were also the radiator, it might work.

I had an inboard Diesel with keel cooling, no worry about weed blockages or winterizing the engine. I was very happy with that. There was a auxilliary water pump to feed the exhaust, that did need regular weed cleaning of its filter, but at least you couldn't cook the engine.

 

I use to do maintenance on a boat 1960`s powered by a Sunbeam Rapier with header tank and heat exchanger cooling running an I/O drive and that set the standard for me
for what I would want any of my boat motors to be like.Especially large expensive installs.

A fresh, treated water cooling system is well recognized as an effective way to preserve your engine. By routing raw water, with its included salt, mud, marine organisms and debris into the corrosion resistant, long lasting heat exchanger system instead of the coolant passages in your engine block, there are fewer places for accumulation of deposits, and the raw water is never exposed to the high temperatures of the block—which can lead to undesirable deposition. The block is in contact with treated fresh water only, normally including anti-freeze and rust inhibitors, which preserve and protect your valuable engine. A closed cooling system provides a foundation for installing cabin and water heating systems using heat from your engine. We make kits for either FULL Systems or HALF Systems. Click on the navigation buttons for an explanation of the difference. Our heat exchanger kits can be easily installed, even while your boat is in the water. A boat fitted with a fresh water cooling system will hold its resale value far better than one which is direct cooled with raw water. You can enjoy your boating experience more knowing that your engine is protected with a quality ORCA Marine Cooling System.

 

Keel outboard I/O`scoolers etc., for

The best option would be for manufacturers to give you the option of having a long life design instead of one with a guaranteed limited useful life.
Air and water flow must be better in a fresh water treated system like an automotive engine and constant temps and quality.
Ambient water temps vary greatly and anti freeze must be a big plus for colder climes.
Dumping raw sea water into your exhaust is not a good option and an outboard gives better options for cooling the exhaust because it is out side of the boat.

 

TheQ,Also an outboard turns to steer, you would either need a flexible joint of some kind, causing restricitions on the turning

That is another reason why swinging all that weight of and outboard from side to side and tilting up and down is not a good way to steer a boat when just moving the lower propeller must be much better, and also it would keep the G/Box out of the water.

 

I seem to recall you were saying these things in the past, Tom, I think it fair to say the swivelling/tilting characrteristics of outboards don't cause much bother.

 

Keel outboard I/O`scoolers etc., for

Fixing bad design was easier a few years ago than it is now.

I had beautifully engineered outboard motor given to me but it had some bad tricks.
It had a gear box with forward and reverse and neutral on the tiller just under the motor.
Cooling was by water scoop and propeller thrust and thermosiphon.
Going slow the motor overheated and also in reverse and it stopped because it was too hot.Heat kills vacuum so induction efficiency dropped.

Waiting for it to cool took too long so cold water had to be poured over it to speed the journey other wise it was a great motor.

The same thing can happen to modern outboards if you leave maintenance to late and probably ruin your motor. A closed water cooling would save the motor from damage.
.

 

Keel outboard I/O`scoolers etc., for

Like adding wrong image to a post things can be changed.

 

you still have to pick up seawater and pump it
plenty of old outboards that have lived in seawater going 50 years later
but outboards are a whole lot better today

 

With the old girl in the image you did not have to have salt water anywhere near it`s insides as it had a dry exhaust and a closed fresh water circulating the motor, after we modified it and we also fitted a ring gear and starter motor and a 12 volt battery for electrics, pumps, When I sold it it was put back to it`s original form as in the photo.

You could run the old penta motor in reverse rotation using a lever fitted to swing the magneto around.
All old outboards were intended to be maintained with regular parts replaced like cylinders, heads, gaskets and other vulnerable parts.

Another bad feature was that the air intake to the carb collected warm air around the motor for induction when cool dense would have been better.

I have saved the lives of many old outboards.

 

As some of you know Seven Marine uses a closed loop cooling system in their outboards. Granted, they are bulky and quite specialized.
http://www.seven-marine.com/technology/cooling/

 

Fresh water cooling in outboards and any marine engine must be a good idea, it just makes sense to protect expensive equipment from corrosion.

http://www.fishing.net.nz/forum/durban-s-70hp-runs-with-radiatorconversion_topic81943_page2.html

 

There are many thousands of good, and even great ideas out there (few of them new), now just try to get people to pay for them. How much would a totally closed cooling system for a 300HP outboard cost? X3 or 4 for many applications.

I have some outboards going on 50 years old that have been used in salt water most of their lives, they still work very well.

 

3 to 4 times as expensive ? How did you arrive at that ?